|
|
@@ -0,0 +1,1894 @@
|
|
|
+/*
|
|
|
+ *
|
|
|
+ * Copyright 2018 gRPC authors.
|
|
|
+ *
|
|
|
+ * Licensed under the Apache License, Version 2.0 (the "License");
|
|
|
+ * you may not use this file except in compliance with the License.
|
|
|
+ * You may obtain a copy of the License at
|
|
|
+ *
|
|
|
+ * http://www.apache.org/licenses/LICENSE-2.0
|
|
|
+ *
|
|
|
+ * Unless required by applicable law or agreed to in writing, software
|
|
|
+ * distributed under the License is distributed on an "AS IS" BASIS,
|
|
|
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
|
+ * See the License for the specific language governing permissions and
|
|
|
+ * limitations under the License.
|
|
|
+ *
|
|
|
+ */
|
|
|
+
|
|
|
+/// Implementation of the gRPC LB policy.
|
|
|
+///
|
|
|
+/// This policy takes as input a list of resolved addresses, which must
|
|
|
+/// include at least one balancer address.
|
|
|
+///
|
|
|
+/// An internal channel (\a lb_channel_) is created for the addresses
|
|
|
+/// from that are balancers. This channel behaves just like a regular
|
|
|
+/// channel that uses pick_first to select from the list of balancer
|
|
|
+/// addresses.
|
|
|
+///
|
|
|
+/// The first time the policy gets a request for a pick, a ping, or to exit
|
|
|
+/// the idle state, \a StartPickingLocked() is called. This method is
|
|
|
+/// responsible for instantiating the internal *streaming* call to the LB
|
|
|
+/// server (whichever address pick_first chose). The call will be complete
|
|
|
+/// when either the balancer sends status or when we cancel the call (e.g.,
|
|
|
+/// because we are shutting down). In needed, we retry the call. If we
|
|
|
+/// received at least one valid message from the server, a new call attempt
|
|
|
+/// will be made immediately; otherwise, we apply back-off delays between
|
|
|
+/// attempts.
|
|
|
+///
|
|
|
+/// We maintain an internal round_robin policy instance for distributing
|
|
|
+/// requests across backends. Whenever we receive a new serverlist from
|
|
|
+/// the balancer, we update the round_robin policy with the new list of
|
|
|
+/// addresses. If we cannot communicate with the balancer on startup,
|
|
|
+/// however, we may enter fallback mode, in which case we will populate
|
|
|
+/// the RR policy's addresses from the backend addresses returned by the
|
|
|
+/// resolver.
|
|
|
+///
|
|
|
+/// Once an RR policy instance is in place (and getting updated as described),
|
|
|
+/// calls for a pick, a ping, or a cancellation will be serviced right
|
|
|
+/// away by forwarding them to the RR instance. Any time there's no RR
|
|
|
+/// policy available (i.e., right after the creation of the gRPCLB policy),
|
|
|
+/// pick and ping requests are added to a list of pending picks and pings
|
|
|
+/// to be flushed and serviced when the RR policy instance becomes available.
|
|
|
+///
|
|
|
+/// \see https://github.com/grpc/grpc/blob/master/doc/load-balancing.md for the
|
|
|
+/// high level design and details.
|
|
|
+
|
|
|
+// With the addition of a libuv endpoint, sockaddr.h now includes uv.h when
|
|
|
+// using that endpoint. Because of various transitive includes in uv.h,
|
|
|
+// including windows.h on Windows, uv.h must be included before other system
|
|
|
+// headers. Therefore, sockaddr.h must always be included first.
|
|
|
+#include <grpc/support/port_platform.h>
|
|
|
+
|
|
|
+#include "src/core/lib/iomgr/sockaddr.h"
|
|
|
+#include "src/core/lib/iomgr/socket_utils.h"
|
|
|
+
|
|
|
+#include <inttypes.h>
|
|
|
+#include <limits.h>
|
|
|
+#include <string.h>
|
|
|
+
|
|
|
+#include <grpc/byte_buffer_reader.h>
|
|
|
+#include <grpc/grpc.h>
|
|
|
+#include <grpc/support/alloc.h>
|
|
|
+#include <grpc/support/string_util.h>
|
|
|
+#include <grpc/support/time.h>
|
|
|
+
|
|
|
+#include "src/core/ext/filters/client_channel/client_channel.h"
|
|
|
+#include "src/core/ext/filters/client_channel/client_channel_factory.h"
|
|
|
+#include "src/core/ext/filters/client_channel/lb_policy/xds/client_load_reporting_filter.h"
|
|
|
+#include "src/core/ext/filters/client_channel/lb_policy/xds/load_balancer_api.h"
|
|
|
+#include "src/core/ext/filters/client_channel/lb_policy/xds/xds.h"
|
|
|
+#include "src/core/ext/filters/client_channel/lb_policy/xds/xds_channel.h"
|
|
|
+#include "src/core/ext/filters/client_channel/lb_policy/xds/xds_client_stats.h"
|
|
|
+#include "src/core/ext/filters/client_channel/lb_policy_factory.h"
|
|
|
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
|
|
|
+#include "src/core/ext/filters/client_channel/parse_address.h"
|
|
|
+#include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h"
|
|
|
+#include "src/core/ext/filters/client_channel/subchannel_index.h"
|
|
|
+#include "src/core/lib/backoff/backoff.h"
|
|
|
+#include "src/core/lib/channel/channel_args.h"
|
|
|
+#include "src/core/lib/channel/channel_stack.h"
|
|
|
+#include "src/core/lib/gpr/host_port.h"
|
|
|
+#include "src/core/lib/gpr/string.h"
|
|
|
+#include "src/core/lib/gprpp/manual_constructor.h"
|
|
|
+#include "src/core/lib/gprpp/memory.h"
|
|
|
+#include "src/core/lib/gprpp/mutex_lock.h"
|
|
|
+#include "src/core/lib/gprpp/orphanable.h"
|
|
|
+#include "src/core/lib/gprpp/ref_counted_ptr.h"
|
|
|
+#include "src/core/lib/iomgr/combiner.h"
|
|
|
+#include "src/core/lib/iomgr/sockaddr.h"
|
|
|
+#include "src/core/lib/iomgr/sockaddr_utils.h"
|
|
|
+#include "src/core/lib/iomgr/timer.h"
|
|
|
+#include "src/core/lib/slice/slice_hash_table.h"
|
|
|
+#include "src/core/lib/slice/slice_internal.h"
|
|
|
+#include "src/core/lib/slice/slice_string_helpers.h"
|
|
|
+#include "src/core/lib/surface/call.h"
|
|
|
+#include "src/core/lib/surface/channel.h"
|
|
|
+#include "src/core/lib/surface/channel_init.h"
|
|
|
+#include "src/core/lib/transport/static_metadata.h"
|
|
|
+
|
|
|
+#define GRPC_XDS_INITIAL_CONNECT_BACKOFF_SECONDS 1
|
|
|
+#define GRPC_XDS_RECONNECT_BACKOFF_MULTIPLIER 1.6
|
|
|
+#define GRPC_XDS_RECONNECT_MAX_BACKOFF_SECONDS 120
|
|
|
+#define GRPC_XDS_RECONNECT_JITTER 0.2
|
|
|
+#define GRPC_XDS_DEFAULT_FALLBACK_TIMEOUT_MS 10000
|
|
|
+
|
|
|
+namespace grpc_core {
|
|
|
+
|
|
|
+TraceFlag grpc_lb_xds_trace(false, "xds");
|
|
|
+
|
|
|
+namespace {
|
|
|
+
|
|
|
+class XdsLb : public LoadBalancingPolicy {
|
|
|
+ public:
|
|
|
+ XdsLb(const grpc_lb_addresses* addresses, const Args& args);
|
|
|
+
|
|
|
+ void UpdateLocked(const grpc_channel_args& args) override;
|
|
|
+ bool PickLocked(PickState* pick, grpc_error** error) override;
|
|
|
+ void CancelPickLocked(PickState* pick, grpc_error* error) override;
|
|
|
+ void CancelMatchingPicksLocked(uint32_t initial_metadata_flags_mask,
|
|
|
+ uint32_t initial_metadata_flags_eq,
|
|
|
+ grpc_error* error) override;
|
|
|
+ void NotifyOnStateChangeLocked(grpc_connectivity_state* state,
|
|
|
+ grpc_closure* closure) override;
|
|
|
+ grpc_connectivity_state CheckConnectivityLocked(
|
|
|
+ grpc_error** connectivity_error) override;
|
|
|
+ void HandOffPendingPicksLocked(LoadBalancingPolicy* new_policy) override;
|
|
|
+ void ExitIdleLocked() override;
|
|
|
+ void ResetBackoffLocked() override;
|
|
|
+ void FillChildRefsForChannelz(
|
|
|
+ channelz::ChildRefsList* child_subchannels,
|
|
|
+ channelz::ChildRefsList* child_channels) override;
|
|
|
+
|
|
|
+ private:
|
|
|
+ /// Linked list of pending pick requests. It stores all information needed to
|
|
|
+ /// eventually call (Round Robin's) pick() on them. They mainly stay pending
|
|
|
+ /// waiting for the RR policy to be created.
|
|
|
+ ///
|
|
|
+ /// Note that when a pick is sent to the RR policy, we inject our own
|
|
|
+ /// on_complete callback, so that we can intercept the result before
|
|
|
+ /// invoking the original on_complete callback. This allows us to set the
|
|
|
+ /// LB token metadata and add client_stats to the call context.
|
|
|
+ /// See \a pending_pick_complete() for details.
|
|
|
+ struct PendingPick {
|
|
|
+ // The xds lb instance that created the wrapping. This instance is not
|
|
|
+ // owned; reference counts are untouched. It's used only for logging
|
|
|
+ // purposes.
|
|
|
+ XdsLb* xdslb_policy;
|
|
|
+ // The original pick.
|
|
|
+ PickState* pick;
|
|
|
+ // Our on_complete closure and the original one.
|
|
|
+ grpc_closure on_complete;
|
|
|
+ grpc_closure* original_on_complete;
|
|
|
+ // The LB token associated with the pick. This is set via user_data in
|
|
|
+ // the pick.
|
|
|
+ grpc_mdelem lb_token;
|
|
|
+ // Stats for client-side load reporting.
|
|
|
+ RefCountedPtr<XdsLbClientStats> client_stats;
|
|
|
+ // Next pending pick.
|
|
|
+ PendingPick* next = nullptr;
|
|
|
+ };
|
|
|
+
|
|
|
+ /// Contains a call to the LB server and all the data related to the call.
|
|
|
+ class BalancerCallState
|
|
|
+ : public InternallyRefCountedWithTracing<BalancerCallState> {
|
|
|
+ public:
|
|
|
+ explicit BalancerCallState(
|
|
|
+ RefCountedPtr<LoadBalancingPolicy> parent_xdslb_policy);
|
|
|
+
|
|
|
+ // It's the caller's responsibility to ensure that Orphan() is called from
|
|
|
+ // inside the combiner.
|
|
|
+ void Orphan() override;
|
|
|
+
|
|
|
+ void StartQuery();
|
|
|
+
|
|
|
+ XdsLbClientStats* client_stats() const { return client_stats_.get(); }
|
|
|
+
|
|
|
+ bool seen_initial_response() const { return seen_initial_response_; }
|
|
|
+
|
|
|
+ private:
|
|
|
+ // So Delete() can access our private dtor.
|
|
|
+ template <typename T>
|
|
|
+ friend void grpc_core::Delete(T*);
|
|
|
+
|
|
|
+ ~BalancerCallState();
|
|
|
+
|
|
|
+ XdsLb* xdslb_policy() const {
|
|
|
+ return static_cast<XdsLb*>(xdslb_policy_.get());
|
|
|
+ }
|
|
|
+
|
|
|
+ void ScheduleNextClientLoadReportLocked();
|
|
|
+ void SendClientLoadReportLocked();
|
|
|
+
|
|
|
+ static bool LoadReportCountersAreZero(xds_grpclb_request* request);
|
|
|
+
|
|
|
+ static void MaybeSendClientLoadReportLocked(void* arg, grpc_error* error);
|
|
|
+ static void ClientLoadReportDoneLocked(void* arg, grpc_error* error);
|
|
|
+ static void OnInitialRequestSentLocked(void* arg, grpc_error* error);
|
|
|
+ static void OnBalancerMessageReceivedLocked(void* arg, grpc_error* error);
|
|
|
+ static void OnBalancerStatusReceivedLocked(void* arg, grpc_error* error);
|
|
|
+
|
|
|
+ // The owning LB policy.
|
|
|
+ RefCountedPtr<LoadBalancingPolicy> xdslb_policy_;
|
|
|
+
|
|
|
+ // The streaming call to the LB server. Always non-NULL.
|
|
|
+ grpc_call* lb_call_ = nullptr;
|
|
|
+
|
|
|
+ // recv_initial_metadata
|
|
|
+ grpc_metadata_array lb_initial_metadata_recv_;
|
|
|
+
|
|
|
+ // send_message
|
|
|
+ grpc_byte_buffer* send_message_payload_ = nullptr;
|
|
|
+ grpc_closure lb_on_initial_request_sent_;
|
|
|
+
|
|
|
+ // recv_message
|
|
|
+ grpc_byte_buffer* recv_message_payload_ = nullptr;
|
|
|
+ grpc_closure lb_on_balancer_message_received_;
|
|
|
+ bool seen_initial_response_ = false;
|
|
|
+
|
|
|
+ // recv_trailing_metadata
|
|
|
+ grpc_closure lb_on_balancer_status_received_;
|
|
|
+ grpc_metadata_array lb_trailing_metadata_recv_;
|
|
|
+ grpc_status_code lb_call_status_;
|
|
|
+ grpc_slice lb_call_status_details_;
|
|
|
+
|
|
|
+ // The stats for client-side load reporting associated with this LB call.
|
|
|
+ // Created after the first serverlist is received.
|
|
|
+ RefCountedPtr<XdsLbClientStats> client_stats_;
|
|
|
+ grpc_millis client_stats_report_interval_ = 0;
|
|
|
+ grpc_timer client_load_report_timer_;
|
|
|
+ bool client_load_report_timer_callback_pending_ = false;
|
|
|
+ bool last_client_load_report_counters_were_zero_ = false;
|
|
|
+ bool client_load_report_is_due_ = false;
|
|
|
+ // The closure used for either the load report timer or the callback for
|
|
|
+ // completion of sending the load report.
|
|
|
+ grpc_closure client_load_report_closure_;
|
|
|
+ };
|
|
|
+
|
|
|
+ ~XdsLb();
|
|
|
+
|
|
|
+ void ShutdownLocked() override;
|
|
|
+
|
|
|
+ // Helper function used in ctor and UpdateLocked().
|
|
|
+ void ProcessChannelArgsLocked(const grpc_channel_args& args);
|
|
|
+
|
|
|
+ // Methods for dealing with the balancer channel and call.
|
|
|
+ void StartPickingLocked();
|
|
|
+ void StartBalancerCallLocked();
|
|
|
+ static void OnFallbackTimerLocked(void* arg, grpc_error* error);
|
|
|
+ void StartBalancerCallRetryTimerLocked();
|
|
|
+ static void OnBalancerCallRetryTimerLocked(void* arg, grpc_error* error);
|
|
|
+ static void OnBalancerChannelConnectivityChangedLocked(void* arg,
|
|
|
+ grpc_error* error);
|
|
|
+
|
|
|
+ // Pending pick methods.
|
|
|
+ static void PendingPickSetMetadataAndContext(PendingPick* pp);
|
|
|
+ PendingPick* PendingPickCreate(PickState* pick);
|
|
|
+ void AddPendingPick(PendingPick* pp);
|
|
|
+ static void OnPendingPickComplete(void* arg, grpc_error* error);
|
|
|
+
|
|
|
+ // Methods for dealing with the RR policy.
|
|
|
+ void CreateOrUpdateRoundRobinPolicyLocked();
|
|
|
+ grpc_channel_args* CreateRoundRobinPolicyArgsLocked();
|
|
|
+ void CreateRoundRobinPolicyLocked(const Args& args);
|
|
|
+ bool PickFromRoundRobinPolicyLocked(bool force_async, PendingPick* pp,
|
|
|
+ grpc_error** error);
|
|
|
+ void UpdateConnectivityStateFromRoundRobinPolicyLocked(
|
|
|
+ grpc_error* rr_state_error);
|
|
|
+ static void OnRoundRobinConnectivityChangedLocked(void* arg,
|
|
|
+ grpc_error* error);
|
|
|
+ static void OnRoundRobinRequestReresolutionLocked(void* arg,
|
|
|
+ grpc_error* error);
|
|
|
+
|
|
|
+ // Who the client is trying to communicate with.
|
|
|
+ const char* server_name_ = nullptr;
|
|
|
+
|
|
|
+ // Current channel args from the resolver.
|
|
|
+ grpc_channel_args* args_ = nullptr;
|
|
|
+
|
|
|
+ // Internal state.
|
|
|
+ bool started_picking_ = false;
|
|
|
+ bool shutting_down_ = false;
|
|
|
+ grpc_connectivity_state_tracker state_tracker_;
|
|
|
+
|
|
|
+ // The channel for communicating with the LB server.
|
|
|
+ grpc_channel* lb_channel_ = nullptr;
|
|
|
+ // Mutex to protect the channel to the LB server. This is used when
|
|
|
+ // processing a channelz request.
|
|
|
+ gpr_mu lb_channel_mu_;
|
|
|
+ grpc_connectivity_state lb_channel_connectivity_;
|
|
|
+ grpc_closure lb_channel_on_connectivity_changed_;
|
|
|
+ // Are we already watching the LB channel's connectivity?
|
|
|
+ bool watching_lb_channel_ = false;
|
|
|
+ // Response generator to inject address updates into lb_channel_.
|
|
|
+ RefCountedPtr<FakeResolverResponseGenerator> response_generator_;
|
|
|
+
|
|
|
+ // The data associated with the current LB call. It holds a ref to this LB
|
|
|
+ // policy. It's initialized every time we query for backends. It's reset to
|
|
|
+ // NULL whenever the current LB call is no longer needed (e.g., the LB policy
|
|
|
+ // is shutting down, or the LB call has ended). A non-NULL lb_calld_ always
|
|
|
+ // contains a non-NULL lb_call_.
|
|
|
+ OrphanablePtr<BalancerCallState> lb_calld_;
|
|
|
+ // Timeout in milliseconds for the LB call. 0 means no deadline.
|
|
|
+ int lb_call_timeout_ms_ = 0;
|
|
|
+ // Balancer call retry state.
|
|
|
+ BackOff lb_call_backoff_;
|
|
|
+ bool retry_timer_callback_pending_ = false;
|
|
|
+ grpc_timer lb_call_retry_timer_;
|
|
|
+ grpc_closure lb_on_call_retry_;
|
|
|
+
|
|
|
+ // The deserialized response from the balancer. May be nullptr until one
|
|
|
+ // such response has arrived.
|
|
|
+ xds_grpclb_serverlist* serverlist_ = nullptr;
|
|
|
+ // Index into serverlist for next pick.
|
|
|
+ // If the server at this index is a drop, we return a drop.
|
|
|
+ // Otherwise, we delegate to the RR policy.
|
|
|
+ size_t serverlist_index_ = 0;
|
|
|
+
|
|
|
+ // Timeout in milliseconds for before using fallback backend addresses.
|
|
|
+ // 0 means not using fallback.
|
|
|
+ int lb_fallback_timeout_ms_ = 0;
|
|
|
+ // The backend addresses from the resolver.
|
|
|
+ grpc_lb_addresses* fallback_backend_addresses_ = nullptr;
|
|
|
+ // Fallback timer.
|
|
|
+ bool fallback_timer_callback_pending_ = false;
|
|
|
+ grpc_timer lb_fallback_timer_;
|
|
|
+ grpc_closure lb_on_fallback_;
|
|
|
+
|
|
|
+ // Pending picks that are waiting on the RR policy's connectivity.
|
|
|
+ PendingPick* pending_picks_ = nullptr;
|
|
|
+
|
|
|
+ // The RR policy to use for the backends.
|
|
|
+ OrphanablePtr<LoadBalancingPolicy> rr_policy_;
|
|
|
+ grpc_connectivity_state rr_connectivity_state_;
|
|
|
+ grpc_closure on_rr_connectivity_changed_;
|
|
|
+ grpc_closure on_rr_request_reresolution_;
|
|
|
+};
|
|
|
+
|
|
|
+//
|
|
|
+// serverlist parsing code
|
|
|
+//
|
|
|
+
|
|
|
+// vtable for LB tokens in grpc_lb_addresses
|
|
|
+void* lb_token_copy(void* token) {
|
|
|
+ return token == nullptr
|
|
|
+ ? nullptr
|
|
|
+ : (void*)GRPC_MDELEM_REF(grpc_mdelem{(uintptr_t)token}).payload;
|
|
|
+}
|
|
|
+void lb_token_destroy(void* token) {
|
|
|
+ if (token != nullptr) {
|
|
|
+ GRPC_MDELEM_UNREF(grpc_mdelem{(uintptr_t)token});
|
|
|
+ }
|
|
|
+}
|
|
|
+int lb_token_cmp(void* token1, void* token2) {
|
|
|
+ if (token1 > token2) return 1;
|
|
|
+ if (token1 < token2) return -1;
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+const grpc_lb_user_data_vtable lb_token_vtable = {
|
|
|
+ lb_token_copy, lb_token_destroy, lb_token_cmp};
|
|
|
+
|
|
|
+// Returns the backend addresses extracted from the given addresses.
|
|
|
+grpc_lb_addresses* ExtractBackendAddresses(const grpc_lb_addresses* addresses) {
|
|
|
+ // First pass: count the number of backend addresses.
|
|
|
+ size_t num_backends = 0;
|
|
|
+ for (size_t i = 0; i < addresses->num_addresses; ++i) {
|
|
|
+ if (!addresses->addresses[i].is_balancer) {
|
|
|
+ ++num_backends;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ // Second pass: actually populate the addresses and (empty) LB tokens.
|
|
|
+ grpc_lb_addresses* backend_addresses =
|
|
|
+ grpc_lb_addresses_create(num_backends, &lb_token_vtable);
|
|
|
+ size_t num_copied = 0;
|
|
|
+ for (size_t i = 0; i < addresses->num_addresses; ++i) {
|
|
|
+ if (addresses->addresses[i].is_balancer) continue;
|
|
|
+ const grpc_resolved_address* addr = &addresses->addresses[i].address;
|
|
|
+ grpc_lb_addresses_set_address(backend_addresses, num_copied, &addr->addr,
|
|
|
+ addr->len, false /* is_balancer */,
|
|
|
+ nullptr /* balancer_name */,
|
|
|
+ (void*)GRPC_MDELEM_LB_TOKEN_EMPTY.payload);
|
|
|
+ ++num_copied;
|
|
|
+ }
|
|
|
+ return backend_addresses;
|
|
|
+}
|
|
|
+
|
|
|
+bool IsServerValid(const xds_grpclb_server* server, size_t idx, bool log) {
|
|
|
+ if (server->drop) return false;
|
|
|
+ const xds_grpclb_ip_address* ip = &server->ip_address;
|
|
|
+ if (GPR_UNLIKELY(server->port >> 16 != 0)) {
|
|
|
+ if (log) {
|
|
|
+ gpr_log(GPR_ERROR,
|
|
|
+ "Invalid port '%d' at index %lu of serverlist. Ignoring.",
|
|
|
+ server->port, (unsigned long)idx);
|
|
|
+ }
|
|
|
+ return false;
|
|
|
+ }
|
|
|
+ if (GPR_UNLIKELY(ip->size != 4 && ip->size != 16)) {
|
|
|
+ if (log) {
|
|
|
+ gpr_log(GPR_ERROR,
|
|
|
+ "Expected IP to be 4 or 16 bytes, got %d at index %lu of "
|
|
|
+ "serverlist. Ignoring",
|
|
|
+ ip->size, (unsigned long)idx);
|
|
|
+ }
|
|
|
+ return false;
|
|
|
+ }
|
|
|
+ return true;
|
|
|
+}
|
|
|
+
|
|
|
+void ParseServer(const xds_grpclb_server* server, grpc_resolved_address* addr) {
|
|
|
+ memset(addr, 0, sizeof(*addr));
|
|
|
+ if (server->drop) return;
|
|
|
+ const uint16_t netorder_port = grpc_htons((uint16_t)server->port);
|
|
|
+ /* the addresses are given in binary format (a in(6)_addr struct) in
|
|
|
+ * server->ip_address.bytes. */
|
|
|
+ const xds_grpclb_ip_address* ip = &server->ip_address;
|
|
|
+ if (ip->size == 4) {
|
|
|
+ addr->len = static_cast<socklen_t>(sizeof(grpc_sockaddr_in));
|
|
|
+ grpc_sockaddr_in* addr4 = reinterpret_cast<grpc_sockaddr_in*>(&addr->addr);
|
|
|
+ addr4->sin_family = GRPC_AF_INET;
|
|
|
+ memcpy(&addr4->sin_addr, ip->bytes, ip->size);
|
|
|
+ addr4->sin_port = netorder_port;
|
|
|
+ } else if (ip->size == 16) {
|
|
|
+ addr->len = static_cast<socklen_t>(sizeof(grpc_sockaddr_in6));
|
|
|
+ grpc_sockaddr_in6* addr6 = (grpc_sockaddr_in6*)&addr->addr;
|
|
|
+ addr6->sin6_family = GRPC_AF_INET6;
|
|
|
+ memcpy(&addr6->sin6_addr, ip->bytes, ip->size);
|
|
|
+ addr6->sin6_port = netorder_port;
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+// Returns addresses extracted from \a serverlist.
|
|
|
+grpc_lb_addresses* ProcessServerlist(const xds_grpclb_serverlist* serverlist) {
|
|
|
+ size_t num_valid = 0;
|
|
|
+ /* first pass: count how many are valid in order to allocate the necessary
|
|
|
+ * memory in a single block */
|
|
|
+ for (size_t i = 0; i < serverlist->num_servers; ++i) {
|
|
|
+ if (IsServerValid(serverlist->servers[i], i, true)) ++num_valid;
|
|
|
+ }
|
|
|
+ grpc_lb_addresses* lb_addresses =
|
|
|
+ grpc_lb_addresses_create(num_valid, &lb_token_vtable);
|
|
|
+ /* second pass: actually populate the addresses and LB tokens (aka user data
|
|
|
+ * to the outside world) to be read by the RR policy during its creation.
|
|
|
+ * Given that the validity tests are very cheap, they are performed again
|
|
|
+ * instead of marking the valid ones during the first pass, as this would
|
|
|
+ * incurr in an allocation due to the arbitrary number of server */
|
|
|
+ size_t addr_idx = 0;
|
|
|
+ for (size_t sl_idx = 0; sl_idx < serverlist->num_servers; ++sl_idx) {
|
|
|
+ const xds_grpclb_server* server = serverlist->servers[sl_idx];
|
|
|
+ if (!IsServerValid(serverlist->servers[sl_idx], sl_idx, false)) continue;
|
|
|
+ GPR_ASSERT(addr_idx < num_valid);
|
|
|
+ /* address processing */
|
|
|
+ grpc_resolved_address addr;
|
|
|
+ ParseServer(server, &addr);
|
|
|
+ /* lb token processing */
|
|
|
+ void* user_data;
|
|
|
+ if (server->has_load_balance_token) {
|
|
|
+ const size_t lb_token_max_length =
|
|
|
+ GPR_ARRAY_SIZE(server->load_balance_token);
|
|
|
+ const size_t lb_token_length =
|
|
|
+ strnlen(server->load_balance_token, lb_token_max_length);
|
|
|
+ grpc_slice lb_token_mdstr = grpc_slice_from_copied_buffer(
|
|
|
+ server->load_balance_token, lb_token_length);
|
|
|
+ user_data =
|
|
|
+ (void*)grpc_mdelem_from_slices(GRPC_MDSTR_LB_TOKEN, lb_token_mdstr)
|
|
|
+ .payload;
|
|
|
+ } else {
|
|
|
+ char* uri = grpc_sockaddr_to_uri(&addr);
|
|
|
+ gpr_log(GPR_INFO,
|
|
|
+ "Missing LB token for backend address '%s'. The empty token will "
|
|
|
+ "be used instead",
|
|
|
+ uri);
|
|
|
+ gpr_free(uri);
|
|
|
+ user_data = (void*)GRPC_MDELEM_LB_TOKEN_EMPTY.payload;
|
|
|
+ }
|
|
|
+ grpc_lb_addresses_set_address(lb_addresses, addr_idx, &addr.addr, addr.len,
|
|
|
+ false /* is_balancer */,
|
|
|
+ nullptr /* balancer_name */, user_data);
|
|
|
+ ++addr_idx;
|
|
|
+ }
|
|
|
+ GPR_ASSERT(addr_idx == num_valid);
|
|
|
+ return lb_addresses;
|
|
|
+}
|
|
|
+
|
|
|
+//
|
|
|
+// XdsLb::BalancerCallState
|
|
|
+//
|
|
|
+
|
|
|
+XdsLb::BalancerCallState::BalancerCallState(
|
|
|
+ RefCountedPtr<LoadBalancingPolicy> parent_xdslb_policy)
|
|
|
+ : InternallyRefCountedWithTracing<BalancerCallState>(&grpc_lb_xds_trace),
|
|
|
+ xdslb_policy_(std::move(parent_xdslb_policy)) {
|
|
|
+ GPR_ASSERT(xdslb_policy_ != nullptr);
|
|
|
+ GPR_ASSERT(!xdslb_policy()->shutting_down_);
|
|
|
+ // Init the LB call. Note that the LB call will progress every time there's
|
|
|
+ // activity in xdslb_policy_->interested_parties(), which is comprised of
|
|
|
+ // the polling entities from client_channel.
|
|
|
+ GPR_ASSERT(xdslb_policy()->server_name_ != nullptr);
|
|
|
+ GPR_ASSERT(xdslb_policy()->server_name_[0] != '\0');
|
|
|
+ const grpc_millis deadline =
|
|
|
+ xdslb_policy()->lb_call_timeout_ms_ == 0
|
|
|
+ ? GRPC_MILLIS_INF_FUTURE
|
|
|
+ : ExecCtx::Get()->Now() + xdslb_policy()->lb_call_timeout_ms_;
|
|
|
+ lb_call_ = grpc_channel_create_pollset_set_call(
|
|
|
+ xdslb_policy()->lb_channel_, nullptr, GRPC_PROPAGATE_DEFAULTS,
|
|
|
+ xdslb_policy_->interested_parties(),
|
|
|
+ GRPC_MDSTR_SLASH_GRPC_DOT_LB_DOT_V1_DOT_LOADBALANCER_SLASH_BALANCELOAD,
|
|
|
+ nullptr, deadline, nullptr);
|
|
|
+ // Init the LB call request payload.
|
|
|
+ xds_grpclb_request* request =
|
|
|
+ xds_grpclb_request_create(xdslb_policy()->server_name_);
|
|
|
+ grpc_slice request_payload_slice = xds_grpclb_request_encode(request);
|
|
|
+ send_message_payload_ =
|
|
|
+ grpc_raw_byte_buffer_create(&request_payload_slice, 1);
|
|
|
+ grpc_slice_unref_internal(request_payload_slice);
|
|
|
+ xds_grpclb_request_destroy(request);
|
|
|
+ // Init other data associated with the LB call.
|
|
|
+ grpc_metadata_array_init(&lb_initial_metadata_recv_);
|
|
|
+ grpc_metadata_array_init(&lb_trailing_metadata_recv_);
|
|
|
+ GRPC_CLOSURE_INIT(&lb_on_initial_request_sent_, OnInitialRequestSentLocked,
|
|
|
+ this, grpc_combiner_scheduler(xdslb_policy()->combiner()));
|
|
|
+ GRPC_CLOSURE_INIT(&lb_on_balancer_message_received_,
|
|
|
+ OnBalancerMessageReceivedLocked, this,
|
|
|
+ grpc_combiner_scheduler(xdslb_policy()->combiner()));
|
|
|
+ GRPC_CLOSURE_INIT(&lb_on_balancer_status_received_,
|
|
|
+ OnBalancerStatusReceivedLocked, this,
|
|
|
+ grpc_combiner_scheduler(xdslb_policy()->combiner()));
|
|
|
+}
|
|
|
+
|
|
|
+XdsLb::BalancerCallState::~BalancerCallState() {
|
|
|
+ GPR_ASSERT(lb_call_ != nullptr);
|
|
|
+ grpc_call_unref(lb_call_);
|
|
|
+ grpc_metadata_array_destroy(&lb_initial_metadata_recv_);
|
|
|
+ grpc_metadata_array_destroy(&lb_trailing_metadata_recv_);
|
|
|
+ grpc_byte_buffer_destroy(send_message_payload_);
|
|
|
+ grpc_byte_buffer_destroy(recv_message_payload_);
|
|
|
+ grpc_slice_unref_internal(lb_call_status_details_);
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::BalancerCallState::Orphan() {
|
|
|
+ GPR_ASSERT(lb_call_ != nullptr);
|
|
|
+ // If we are here because xdslb_policy wants to cancel the call,
|
|
|
+ // lb_on_balancer_status_received_ will complete the cancellation and clean
|
|
|
+ // up. Otherwise, we are here because xdslb_policy has to orphan a failed
|
|
|
+ // call, then the following cancellation will be a no-op.
|
|
|
+ grpc_call_cancel(lb_call_, nullptr);
|
|
|
+ if (client_load_report_timer_callback_pending_) {
|
|
|
+ grpc_timer_cancel(&client_load_report_timer_);
|
|
|
+ }
|
|
|
+ // Note that the initial ref is hold by lb_on_balancer_status_received_
|
|
|
+ // instead of the caller of this function. So the corresponding unref happens
|
|
|
+ // in lb_on_balancer_status_received_ instead of here.
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::BalancerCallState::StartQuery() {
|
|
|
+ GPR_ASSERT(lb_call_ != nullptr);
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] Starting LB call (lb_calld: %p, lb_call: %p)",
|
|
|
+ xdslb_policy_.get(), this, lb_call_);
|
|
|
+ }
|
|
|
+ // Create the ops.
|
|
|
+ grpc_call_error call_error;
|
|
|
+ grpc_op ops[3];
|
|
|
+ memset(ops, 0, sizeof(ops));
|
|
|
+ // Op: send initial metadata.
|
|
|
+ grpc_op* op = ops;
|
|
|
+ op->op = GRPC_OP_SEND_INITIAL_METADATA;
|
|
|
+ op->data.send_initial_metadata.count = 0;
|
|
|
+ op->flags = 0;
|
|
|
+ op->reserved = nullptr;
|
|
|
+ op++;
|
|
|
+ // Op: send request message.
|
|
|
+ GPR_ASSERT(send_message_payload_ != nullptr);
|
|
|
+ op->op = GRPC_OP_SEND_MESSAGE;
|
|
|
+ op->data.send_message.send_message = send_message_payload_;
|
|
|
+ op->flags = 0;
|
|
|
+ op->reserved = nullptr;
|
|
|
+ op++;
|
|
|
+ // TODO(roth): We currently track this ref manually. Once the
|
|
|
+ // ClosureRef API is ready, we should pass the RefCountedPtr<> along
|
|
|
+ // with the callback.
|
|
|
+ auto self = Ref(DEBUG_LOCATION, "on_initial_request_sent");
|
|
|
+ self.release();
|
|
|
+ call_error = grpc_call_start_batch_and_execute(
|
|
|
+ lb_call_, ops, (size_t)(op - ops), &lb_on_initial_request_sent_);
|
|
|
+ GPR_ASSERT(GRPC_CALL_OK == call_error);
|
|
|
+ // Op: recv initial metadata.
|
|
|
+ op = ops;
|
|
|
+ op->op = GRPC_OP_RECV_INITIAL_METADATA;
|
|
|
+ op->data.recv_initial_metadata.recv_initial_metadata =
|
|
|
+ &lb_initial_metadata_recv_;
|
|
|
+ op->flags = 0;
|
|
|
+ op->reserved = nullptr;
|
|
|
+ op++;
|
|
|
+ // Op: recv response.
|
|
|
+ op->op = GRPC_OP_RECV_MESSAGE;
|
|
|
+ op->data.recv_message.recv_message = &recv_message_payload_;
|
|
|
+ op->flags = 0;
|
|
|
+ op->reserved = nullptr;
|
|
|
+ op++;
|
|
|
+ // TODO(roth): We currently track this ref manually. Once the
|
|
|
+ // ClosureRef API is ready, we should pass the RefCountedPtr<> along
|
|
|
+ // with the callback.
|
|
|
+ self = Ref(DEBUG_LOCATION, "on_message_received");
|
|
|
+ self.release();
|
|
|
+ call_error = grpc_call_start_batch_and_execute(
|
|
|
+ lb_call_, ops, (size_t)(op - ops), &lb_on_balancer_message_received_);
|
|
|
+ GPR_ASSERT(GRPC_CALL_OK == call_error);
|
|
|
+ // Op: recv server status.
|
|
|
+ op = ops;
|
|
|
+ op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
|
|
|
+ op->data.recv_status_on_client.trailing_metadata =
|
|
|
+ &lb_trailing_metadata_recv_;
|
|
|
+ op->data.recv_status_on_client.status = &lb_call_status_;
|
|
|
+ op->data.recv_status_on_client.status_details = &lb_call_status_details_;
|
|
|
+ op->flags = 0;
|
|
|
+ op->reserved = nullptr;
|
|
|
+ op++;
|
|
|
+ // This callback signals the end of the LB call, so it relies on the initial
|
|
|
+ // ref instead of a new ref. When it's invoked, it's the initial ref that is
|
|
|
+ // unreffed.
|
|
|
+ call_error = grpc_call_start_batch_and_execute(
|
|
|
+ lb_call_, ops, (size_t)(op - ops), &lb_on_balancer_status_received_);
|
|
|
+ GPR_ASSERT(GRPC_CALL_OK == call_error);
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::BalancerCallState::ScheduleNextClientLoadReportLocked() {
|
|
|
+ const grpc_millis next_client_load_report_time =
|
|
|
+ ExecCtx::Get()->Now() + client_stats_report_interval_;
|
|
|
+ GRPC_CLOSURE_INIT(&client_load_report_closure_,
|
|
|
+ MaybeSendClientLoadReportLocked, this,
|
|
|
+ grpc_combiner_scheduler(xdslb_policy()->combiner()));
|
|
|
+ grpc_timer_init(&client_load_report_timer_, next_client_load_report_time,
|
|
|
+ &client_load_report_closure_);
|
|
|
+ client_load_report_timer_callback_pending_ = true;
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::BalancerCallState::MaybeSendClientLoadReportLocked(
|
|
|
+ void* arg, grpc_error* error) {
|
|
|
+ BalancerCallState* lb_calld = static_cast<BalancerCallState*>(arg);
|
|
|
+ XdsLb* xdslb_policy = lb_calld->xdslb_policy();
|
|
|
+ lb_calld->client_load_report_timer_callback_pending_ = false;
|
|
|
+ if (error != GRPC_ERROR_NONE || lb_calld != xdslb_policy->lb_calld_.get()) {
|
|
|
+ lb_calld->Unref(DEBUG_LOCATION, "client_load_report");
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ // If we've already sent the initial request, then we can go ahead and send
|
|
|
+ // the load report. Otherwise, we need to wait until the initial request has
|
|
|
+ // been sent to send this (see OnInitialRequestSentLocked()).
|
|
|
+ if (lb_calld->send_message_payload_ == nullptr) {
|
|
|
+ lb_calld->SendClientLoadReportLocked();
|
|
|
+ } else {
|
|
|
+ lb_calld->client_load_report_is_due_ = true;
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+bool XdsLb::BalancerCallState::LoadReportCountersAreZero(
|
|
|
+ xds_grpclb_request* request) {
|
|
|
+ XdsLbClientStats::DroppedCallCounts* drop_entries =
|
|
|
+ static_cast<XdsLbClientStats::DroppedCallCounts*>(
|
|
|
+ request->client_stats.calls_finished_with_drop.arg);
|
|
|
+ return request->client_stats.num_calls_started == 0 &&
|
|
|
+ request->client_stats.num_calls_finished == 0 &&
|
|
|
+ request->client_stats.num_calls_finished_with_client_failed_to_send ==
|
|
|
+ 0 &&
|
|
|
+ request->client_stats.num_calls_finished_known_received == 0 &&
|
|
|
+ (drop_entries == nullptr || drop_entries->empty());
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::BalancerCallState::SendClientLoadReportLocked() {
|
|
|
+ // Construct message payload.
|
|
|
+ GPR_ASSERT(send_message_payload_ == nullptr);
|
|
|
+ xds_grpclb_request* request =
|
|
|
+ xds_grpclb_load_report_request_create_locked(client_stats_.get());
|
|
|
+ // Skip client load report if the counters were all zero in the last
|
|
|
+ // report and they are still zero in this one.
|
|
|
+ if (LoadReportCountersAreZero(request)) {
|
|
|
+ if (last_client_load_report_counters_were_zero_) {
|
|
|
+ xds_grpclb_request_destroy(request);
|
|
|
+ ScheduleNextClientLoadReportLocked();
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ last_client_load_report_counters_were_zero_ = true;
|
|
|
+ } else {
|
|
|
+ last_client_load_report_counters_were_zero_ = false;
|
|
|
+ }
|
|
|
+ grpc_slice request_payload_slice = xds_grpclb_request_encode(request);
|
|
|
+ send_message_payload_ =
|
|
|
+ grpc_raw_byte_buffer_create(&request_payload_slice, 1);
|
|
|
+ grpc_slice_unref_internal(request_payload_slice);
|
|
|
+ xds_grpclb_request_destroy(request);
|
|
|
+ // Send the report.
|
|
|
+ grpc_op op;
|
|
|
+ memset(&op, 0, sizeof(op));
|
|
|
+ op.op = GRPC_OP_SEND_MESSAGE;
|
|
|
+ op.data.send_message.send_message = send_message_payload_;
|
|
|
+ GRPC_CLOSURE_INIT(&client_load_report_closure_, ClientLoadReportDoneLocked,
|
|
|
+ this, grpc_combiner_scheduler(xdslb_policy()->combiner()));
|
|
|
+ grpc_call_error call_error = grpc_call_start_batch_and_execute(
|
|
|
+ lb_call_, &op, 1, &client_load_report_closure_);
|
|
|
+ if (GPR_UNLIKELY(call_error != GRPC_CALL_OK)) {
|
|
|
+ gpr_log(GPR_ERROR, "[xdslb %p] call_error=%d", xdslb_policy_.get(),
|
|
|
+ call_error);
|
|
|
+ GPR_ASSERT(GRPC_CALL_OK == call_error);
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::BalancerCallState::ClientLoadReportDoneLocked(void* arg,
|
|
|
+ grpc_error* error) {
|
|
|
+ BalancerCallState* lb_calld = static_cast<BalancerCallState*>(arg);
|
|
|
+ XdsLb* xdslb_policy = lb_calld->xdslb_policy();
|
|
|
+ grpc_byte_buffer_destroy(lb_calld->send_message_payload_);
|
|
|
+ lb_calld->send_message_payload_ = nullptr;
|
|
|
+ if (error != GRPC_ERROR_NONE || lb_calld != xdslb_policy->lb_calld_.get()) {
|
|
|
+ lb_calld->Unref(DEBUG_LOCATION, "client_load_report");
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ lb_calld->ScheduleNextClientLoadReportLocked();
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::BalancerCallState::OnInitialRequestSentLocked(void* arg,
|
|
|
+ grpc_error* error) {
|
|
|
+ BalancerCallState* lb_calld = static_cast<BalancerCallState*>(arg);
|
|
|
+ grpc_byte_buffer_destroy(lb_calld->send_message_payload_);
|
|
|
+ lb_calld->send_message_payload_ = nullptr;
|
|
|
+ // If we attempted to send a client load report before the initial request was
|
|
|
+ // sent (and this lb_calld is still in use), send the load report now.
|
|
|
+ if (lb_calld->client_load_report_is_due_ &&
|
|
|
+ lb_calld == lb_calld->xdslb_policy()->lb_calld_.get()) {
|
|
|
+ lb_calld->SendClientLoadReportLocked();
|
|
|
+ lb_calld->client_load_report_is_due_ = false;
|
|
|
+ }
|
|
|
+ lb_calld->Unref(DEBUG_LOCATION, "on_initial_request_sent");
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::BalancerCallState::OnBalancerMessageReceivedLocked(
|
|
|
+ void* arg, grpc_error* error) {
|
|
|
+ BalancerCallState* lb_calld = static_cast<BalancerCallState*>(arg);
|
|
|
+ XdsLb* xdslb_policy = lb_calld->xdslb_policy();
|
|
|
+ // Empty payload means the LB call was cancelled.
|
|
|
+ if (lb_calld != xdslb_policy->lb_calld_.get() ||
|
|
|
+ lb_calld->recv_message_payload_ == nullptr) {
|
|
|
+ lb_calld->Unref(DEBUG_LOCATION, "on_message_received");
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ grpc_byte_buffer_reader bbr;
|
|
|
+ grpc_byte_buffer_reader_init(&bbr, lb_calld->recv_message_payload_);
|
|
|
+ grpc_slice response_slice = grpc_byte_buffer_reader_readall(&bbr);
|
|
|
+ grpc_byte_buffer_reader_destroy(&bbr);
|
|
|
+ grpc_byte_buffer_destroy(lb_calld->recv_message_payload_);
|
|
|
+ lb_calld->recv_message_payload_ = nullptr;
|
|
|
+ xds_grpclb_initial_response* initial_response;
|
|
|
+ xds_grpclb_serverlist* serverlist;
|
|
|
+ if (!lb_calld->seen_initial_response_ &&
|
|
|
+ (initial_response = xds_grpclb_initial_response_parse(response_slice)) !=
|
|
|
+ nullptr) {
|
|
|
+ // Have NOT seen initial response, look for initial response.
|
|
|
+ if (initial_response->has_client_stats_report_interval) {
|
|
|
+ lb_calld->client_stats_report_interval_ = GPR_MAX(
|
|
|
+ GPR_MS_PER_SEC, xds_grpclb_duration_to_millis(
|
|
|
+ &initial_response->client_stats_report_interval));
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO,
|
|
|
+ "[xdslb %p] Received initial LB response message; "
|
|
|
+ "client load reporting interval = %" PRId64 " milliseconds",
|
|
|
+ xdslb_policy, lb_calld->client_stats_report_interval_);
|
|
|
+ }
|
|
|
+ } else if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO,
|
|
|
+ "[xdslb %p] Received initial LB response message; client load "
|
|
|
+ "reporting NOT enabled",
|
|
|
+ xdslb_policy);
|
|
|
+ }
|
|
|
+ xds_grpclb_initial_response_destroy(initial_response);
|
|
|
+ lb_calld->seen_initial_response_ = true;
|
|
|
+ } else if ((serverlist = xds_grpclb_response_parse_serverlist(
|
|
|
+ response_slice)) != nullptr) {
|
|
|
+ // Have seen initial response, look for serverlist.
|
|
|
+ GPR_ASSERT(lb_calld->lb_call_ != nullptr);
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO,
|
|
|
+ "[xdslb %p] Serverlist with %" PRIuPTR " servers received",
|
|
|
+ xdslb_policy, serverlist->num_servers);
|
|
|
+ for (size_t i = 0; i < serverlist->num_servers; ++i) {
|
|
|
+ grpc_resolved_address addr;
|
|
|
+ ParseServer(serverlist->servers[i], &addr);
|
|
|
+ char* ipport;
|
|
|
+ grpc_sockaddr_to_string(&ipport, &addr, false);
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] Serverlist[%" PRIuPTR "]: %s",
|
|
|
+ xdslb_policy, i, ipport);
|
|
|
+ gpr_free(ipport);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ /* update serverlist */
|
|
|
+ if (serverlist->num_servers > 0) {
|
|
|
+ // Start sending client load report only after we start using the
|
|
|
+ // serverlist returned from the current LB call.
|
|
|
+ if (lb_calld->client_stats_report_interval_ > 0 &&
|
|
|
+ lb_calld->client_stats_ == nullptr) {
|
|
|
+ lb_calld->client_stats_.reset(New<XdsLbClientStats>());
|
|
|
+ // TODO(roth): We currently track this ref manually. Once the
|
|
|
+ // ClosureRef API is ready, we should pass the RefCountedPtr<> along
|
|
|
+ // with the callback.
|
|
|
+ auto self = lb_calld->Ref(DEBUG_LOCATION, "client_load_report");
|
|
|
+ self.release();
|
|
|
+ lb_calld->ScheduleNextClientLoadReportLocked();
|
|
|
+ }
|
|
|
+ if (xds_grpclb_serverlist_equals(xdslb_policy->serverlist_, serverlist)) {
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO,
|
|
|
+ "[xdslb %p] Incoming server list identical to current, "
|
|
|
+ "ignoring.",
|
|
|
+ xdslb_policy);
|
|
|
+ }
|
|
|
+ xds_grpclb_destroy_serverlist(serverlist);
|
|
|
+ } else { /* new serverlist */
|
|
|
+ if (xdslb_policy->serverlist_ != nullptr) {
|
|
|
+ /* dispose of the old serverlist */
|
|
|
+ xds_grpclb_destroy_serverlist(xdslb_policy->serverlist_);
|
|
|
+ } else {
|
|
|
+ /* or dispose of the fallback */
|
|
|
+ grpc_lb_addresses_destroy(xdslb_policy->fallback_backend_addresses_);
|
|
|
+ xdslb_policy->fallback_backend_addresses_ = nullptr;
|
|
|
+ if (xdslb_policy->fallback_timer_callback_pending_) {
|
|
|
+ grpc_timer_cancel(&xdslb_policy->lb_fallback_timer_);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ // and update the copy in the XdsLb instance. This
|
|
|
+ // serverlist instance will be destroyed either upon the next
|
|
|
+ // update or when the XdsLb instance is destroyed.
|
|
|
+ xdslb_policy->serverlist_ = serverlist;
|
|
|
+ xdslb_policy->serverlist_index_ = 0;
|
|
|
+ xdslb_policy->CreateOrUpdateRoundRobinPolicyLocked();
|
|
|
+ }
|
|
|
+ } else {
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] Received empty server list, ignoring.",
|
|
|
+ xdslb_policy);
|
|
|
+ }
|
|
|
+ xds_grpclb_destroy_serverlist(serverlist);
|
|
|
+ }
|
|
|
+ } else {
|
|
|
+ // No valid initial response or serverlist found.
|
|
|
+ char* response_slice_str =
|
|
|
+ grpc_dump_slice(response_slice, GPR_DUMP_ASCII | GPR_DUMP_HEX);
|
|
|
+ gpr_log(GPR_ERROR,
|
|
|
+ "[xdslb %p] Invalid LB response received: '%s'. Ignoring.",
|
|
|
+ xdslb_policy, response_slice_str);
|
|
|
+ gpr_free(response_slice_str);
|
|
|
+ }
|
|
|
+ grpc_slice_unref_internal(response_slice);
|
|
|
+ if (!xdslb_policy->shutting_down_) {
|
|
|
+ // Keep listening for serverlist updates.
|
|
|
+ grpc_op op;
|
|
|
+ memset(&op, 0, sizeof(op));
|
|
|
+ op.op = GRPC_OP_RECV_MESSAGE;
|
|
|
+ op.data.recv_message.recv_message = &lb_calld->recv_message_payload_;
|
|
|
+ op.flags = 0;
|
|
|
+ op.reserved = nullptr;
|
|
|
+ // Reuse the "OnBalancerMessageReceivedLocked" ref taken in StartQuery().
|
|
|
+ const grpc_call_error call_error = grpc_call_start_batch_and_execute(
|
|
|
+ lb_calld->lb_call_, &op, 1,
|
|
|
+ &lb_calld->lb_on_balancer_message_received_);
|
|
|
+ GPR_ASSERT(GRPC_CALL_OK == call_error);
|
|
|
+ } else {
|
|
|
+ lb_calld->Unref(DEBUG_LOCATION, "on_message_received+grpclb_shutdown");
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::BalancerCallState::OnBalancerStatusReceivedLocked(
|
|
|
+ void* arg, grpc_error* error) {
|
|
|
+ BalancerCallState* lb_calld = static_cast<BalancerCallState*>(arg);
|
|
|
+ XdsLb* xdslb_policy = lb_calld->xdslb_policy();
|
|
|
+ GPR_ASSERT(lb_calld->lb_call_ != nullptr);
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ char* status_details =
|
|
|
+ grpc_slice_to_c_string(lb_calld->lb_call_status_details_);
|
|
|
+ gpr_log(GPR_INFO,
|
|
|
+ "[xdslb %p] Status from LB server received. Status = %d, details "
|
|
|
+ "= '%s', (lb_calld: %p, lb_call: %p), error '%s'",
|
|
|
+ xdslb_policy, lb_calld->lb_call_status_, status_details, lb_calld,
|
|
|
+ lb_calld->lb_call_, grpc_error_string(error));
|
|
|
+ gpr_free(status_details);
|
|
|
+ }
|
|
|
+ xdslb_policy->TryReresolutionLocked(&grpc_lb_xds_trace, GRPC_ERROR_NONE);
|
|
|
+ // If this lb_calld is still in use, this call ended because of a failure so
|
|
|
+ // we want to retry connecting. Otherwise, we have deliberately ended this
|
|
|
+ // call and no further action is required.
|
|
|
+ if (lb_calld == xdslb_policy->lb_calld_.get()) {
|
|
|
+ xdslb_policy->lb_calld_.reset();
|
|
|
+ GPR_ASSERT(!xdslb_policy->shutting_down_);
|
|
|
+ if (lb_calld->seen_initial_response_) {
|
|
|
+ // If we lose connection to the LB server, reset the backoff and restart
|
|
|
+ // the LB call immediately.
|
|
|
+ xdslb_policy->lb_call_backoff_.Reset();
|
|
|
+ xdslb_policy->StartBalancerCallLocked();
|
|
|
+ } else {
|
|
|
+ // If this LB call fails establishing any connection to the LB server,
|
|
|
+ // retry later.
|
|
|
+ xdslb_policy->StartBalancerCallRetryTimerLocked();
|
|
|
+ }
|
|
|
+ }
|
|
|
+ lb_calld->Unref(DEBUG_LOCATION, "lb_call_ended");
|
|
|
+}
|
|
|
+
|
|
|
+//
|
|
|
+// helper code for creating balancer channel
|
|
|
+//
|
|
|
+
|
|
|
+grpc_lb_addresses* ExtractBalancerAddresses(
|
|
|
+ const grpc_lb_addresses* addresses) {
|
|
|
+ size_t num_grpclb_addrs = 0;
|
|
|
+ for (size_t i = 0; i < addresses->num_addresses; ++i) {
|
|
|
+ if (addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
|
|
|
+ }
|
|
|
+ // There must be at least one balancer address, or else the
|
|
|
+ // client_channel would not have chosen this LB policy.
|
|
|
+ GPR_ASSERT(num_grpclb_addrs > 0);
|
|
|
+ grpc_lb_addresses* lb_addresses =
|
|
|
+ grpc_lb_addresses_create(num_grpclb_addrs, nullptr);
|
|
|
+ size_t lb_addresses_idx = 0;
|
|
|
+ for (size_t i = 0; i < addresses->num_addresses; ++i) {
|
|
|
+ if (!addresses->addresses[i].is_balancer) continue;
|
|
|
+ if (GPR_UNLIKELY(addresses->addresses[i].user_data != nullptr)) {
|
|
|
+ gpr_log(GPR_ERROR,
|
|
|
+ "This LB policy doesn't support user data. It will be ignored");
|
|
|
+ }
|
|
|
+ grpc_lb_addresses_set_address(
|
|
|
+ lb_addresses, lb_addresses_idx++, addresses->addresses[i].address.addr,
|
|
|
+ addresses->addresses[i].address.len, false /* is balancer */,
|
|
|
+ addresses->addresses[i].balancer_name, nullptr /* user data */);
|
|
|
+ }
|
|
|
+ GPR_ASSERT(num_grpclb_addrs == lb_addresses_idx);
|
|
|
+ return lb_addresses;
|
|
|
+}
|
|
|
+
|
|
|
+/* Returns the channel args for the LB channel, used to create a bidirectional
|
|
|
+ * stream for the reception of load balancing updates.
|
|
|
+ *
|
|
|
+ * Inputs:
|
|
|
+ * - \a addresses: corresponding to the balancers.
|
|
|
+ * - \a response_generator: in order to propagate updates from the resolver
|
|
|
+ * above the grpclb policy.
|
|
|
+ * - \a args: other args inherited from the grpclb policy. */
|
|
|
+grpc_channel_args* BuildBalancerChannelArgs(
|
|
|
+ const grpc_lb_addresses* addresses,
|
|
|
+ FakeResolverResponseGenerator* response_generator,
|
|
|
+ const grpc_channel_args* args) {
|
|
|
+ grpc_lb_addresses* lb_addresses = ExtractBalancerAddresses(addresses);
|
|
|
+ // Channel args to remove.
|
|
|
+ static const char* args_to_remove[] = {
|
|
|
+ // LB policy name, since we want to use the default (pick_first) in
|
|
|
+ // the LB channel.
|
|
|
+ GRPC_ARG_LB_POLICY_NAME,
|
|
|
+ // The channel arg for the server URI, since that will be different for
|
|
|
+ // the LB channel than for the parent channel. The client channel
|
|
|
+ // factory will re-add this arg with the right value.
|
|
|
+ GRPC_ARG_SERVER_URI,
|
|
|
+ // The resolved addresses, which will be generated by the name resolver
|
|
|
+ // used in the LB channel. Note that the LB channel will use the fake
|
|
|
+ // resolver, so this won't actually generate a query to DNS (or some
|
|
|
+ // other name service). However, the addresses returned by the fake
|
|
|
+ // resolver will have is_balancer=false, whereas our own addresses have
|
|
|
+ // is_balancer=true. We need the LB channel to return addresses with
|
|
|
+ // is_balancer=false so that it does not wind up recursively using the
|
|
|
+ // grpclb LB policy, as per the special case logic in client_channel.c.
|
|
|
+ GRPC_ARG_LB_ADDRESSES,
|
|
|
+ // The fake resolver response generator, because we are replacing it
|
|
|
+ // with the one from the grpclb policy, used to propagate updates to
|
|
|
+ // the LB channel.
|
|
|
+ GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR,
|
|
|
+ // The LB channel should use the authority indicated by the target
|
|
|
+ // authority table (see \a grpc_lb_policy_xds_modify_lb_channel_args),
|
|
|
+ // as opposed to the authority from the parent channel.
|
|
|
+ GRPC_ARG_DEFAULT_AUTHORITY,
|
|
|
+ // Just as for \a GRPC_ARG_DEFAULT_AUTHORITY, the LB channel should be
|
|
|
+ // treated as a stand-alone channel and not inherit this argument from the
|
|
|
+ // args of the parent channel.
|
|
|
+ GRPC_SSL_TARGET_NAME_OVERRIDE_ARG,
|
|
|
+ };
|
|
|
+ // Channel args to add.
|
|
|
+ const grpc_arg args_to_add[] = {
|
|
|
+ // New LB addresses.
|
|
|
+ // Note that we pass these in both when creating the LB channel
|
|
|
+ // and via the fake resolver. The latter is what actually gets used.
|
|
|
+ grpc_lb_addresses_create_channel_arg(lb_addresses),
|
|
|
+ // The fake resolver response generator, which we use to inject
|
|
|
+ // address updates into the LB channel.
|
|
|
+ grpc_core::FakeResolverResponseGenerator::MakeChannelArg(
|
|
|
+ response_generator),
|
|
|
+ // A channel arg indicating the target is a grpclb load balancer.
|
|
|
+ grpc_channel_arg_integer_create(
|
|
|
+ const_cast<char*>(GRPC_ARG_ADDRESS_IS_XDS_LOAD_BALANCER), 1),
|
|
|
+ // A channel arg indicating this is an internal channels, aka it is
|
|
|
+ // owned by components in Core, not by the user application.
|
|
|
+ grpc_channel_arg_integer_create(
|
|
|
+ const_cast<char*>(GRPC_ARG_CHANNELZ_CHANNEL_IS_INTERNAL_CHANNEL), 1),
|
|
|
+ };
|
|
|
+ // Construct channel args.
|
|
|
+ grpc_channel_args* new_args = grpc_channel_args_copy_and_add_and_remove(
|
|
|
+ args, args_to_remove, GPR_ARRAY_SIZE(args_to_remove), args_to_add,
|
|
|
+ GPR_ARRAY_SIZE(args_to_add));
|
|
|
+ // Make any necessary modifications for security.
|
|
|
+ new_args = grpc_lb_policy_xds_modify_lb_channel_args(new_args);
|
|
|
+ // Clean up.
|
|
|
+ grpc_lb_addresses_destroy(lb_addresses);
|
|
|
+ return new_args;
|
|
|
+}
|
|
|
+
|
|
|
+//
|
|
|
+// ctor and dtor
|
|
|
+//
|
|
|
+
|
|
|
+XdsLb::XdsLb(const grpc_lb_addresses* addresses,
|
|
|
+ const LoadBalancingPolicy::Args& args)
|
|
|
+ : LoadBalancingPolicy(args),
|
|
|
+ response_generator_(MakeRefCounted<FakeResolverResponseGenerator>()),
|
|
|
+ lb_call_backoff_(
|
|
|
+ BackOff::Options()
|
|
|
+ .set_initial_backoff(GRPC_XDS_INITIAL_CONNECT_BACKOFF_SECONDS *
|
|
|
+ 1000)
|
|
|
+ .set_multiplier(GRPC_XDS_RECONNECT_BACKOFF_MULTIPLIER)
|
|
|
+ .set_jitter(GRPC_XDS_RECONNECT_JITTER)
|
|
|
+ .set_max_backoff(GRPC_XDS_RECONNECT_MAX_BACKOFF_SECONDS * 1000)) {
|
|
|
+ // Initialization.
|
|
|
+ gpr_mu_init(&lb_channel_mu_);
|
|
|
+ grpc_subchannel_index_ref();
|
|
|
+ GRPC_CLOSURE_INIT(&lb_channel_on_connectivity_changed_,
|
|
|
+ &XdsLb::OnBalancerChannelConnectivityChangedLocked, this,
|
|
|
+ grpc_combiner_scheduler(args.combiner));
|
|
|
+ GRPC_CLOSURE_INIT(&on_rr_connectivity_changed_,
|
|
|
+ &XdsLb::OnRoundRobinConnectivityChangedLocked, this,
|
|
|
+ grpc_combiner_scheduler(args.combiner));
|
|
|
+ GRPC_CLOSURE_INIT(&on_rr_request_reresolution_,
|
|
|
+ &XdsLb::OnRoundRobinRequestReresolutionLocked, this,
|
|
|
+ grpc_combiner_scheduler(args.combiner));
|
|
|
+ grpc_connectivity_state_init(&state_tracker_, GRPC_CHANNEL_IDLE, "xds");
|
|
|
+ // Record server name.
|
|
|
+ const grpc_arg* arg = grpc_channel_args_find(args.args, GRPC_ARG_SERVER_URI);
|
|
|
+ const char* server_uri = grpc_channel_arg_get_string(arg);
|
|
|
+ GPR_ASSERT(server_uri != nullptr);
|
|
|
+ grpc_uri* uri = grpc_uri_parse(server_uri, true);
|
|
|
+ GPR_ASSERT(uri->path[0] != '\0');
|
|
|
+ server_name_ = gpr_strdup(uri->path[0] == '/' ? uri->path + 1 : uri->path);
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO,
|
|
|
+ "[xdslb %p] Will use '%s' as the server name for LB request.", this,
|
|
|
+ server_name_);
|
|
|
+ }
|
|
|
+ grpc_uri_destroy(uri);
|
|
|
+ // Record LB call timeout.
|
|
|
+ arg = grpc_channel_args_find(args.args, GRPC_ARG_GRPCLB_CALL_TIMEOUT_MS);
|
|
|
+ lb_call_timeout_ms_ = grpc_channel_arg_get_integer(arg, {0, 0, INT_MAX});
|
|
|
+ // Record fallback timeout.
|
|
|
+ arg = grpc_channel_args_find(args.args, GRPC_ARG_GRPCLB_FALLBACK_TIMEOUT_MS);
|
|
|
+ lb_fallback_timeout_ms_ = grpc_channel_arg_get_integer(
|
|
|
+ arg, {GRPC_XDS_DEFAULT_FALLBACK_TIMEOUT_MS, 0, INT_MAX});
|
|
|
+ // Process channel args.
|
|
|
+ ProcessChannelArgsLocked(*args.args);
|
|
|
+}
|
|
|
+
|
|
|
+XdsLb::~XdsLb() {
|
|
|
+ GPR_ASSERT(pending_picks_ == nullptr);
|
|
|
+ gpr_mu_destroy(&lb_channel_mu_);
|
|
|
+ gpr_free((void*)server_name_);
|
|
|
+ grpc_channel_args_destroy(args_);
|
|
|
+ grpc_connectivity_state_destroy(&state_tracker_);
|
|
|
+ if (serverlist_ != nullptr) {
|
|
|
+ xds_grpclb_destroy_serverlist(serverlist_);
|
|
|
+ }
|
|
|
+ if (fallback_backend_addresses_ != nullptr) {
|
|
|
+ grpc_lb_addresses_destroy(fallback_backend_addresses_);
|
|
|
+ }
|
|
|
+ grpc_subchannel_index_unref();
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::ShutdownLocked() {
|
|
|
+ grpc_error* error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel shutdown");
|
|
|
+ shutting_down_ = true;
|
|
|
+ lb_calld_.reset();
|
|
|
+ if (retry_timer_callback_pending_) {
|
|
|
+ grpc_timer_cancel(&lb_call_retry_timer_);
|
|
|
+ }
|
|
|
+ if (fallback_timer_callback_pending_) {
|
|
|
+ grpc_timer_cancel(&lb_fallback_timer_);
|
|
|
+ }
|
|
|
+ rr_policy_.reset();
|
|
|
+ TryReresolutionLocked(&grpc_lb_xds_trace, GRPC_ERROR_CANCELLED);
|
|
|
+ // We destroy the LB channel here instead of in our destructor because
|
|
|
+ // destroying the channel triggers a last callback to
|
|
|
+ // OnBalancerChannelConnectivityChangedLocked(), and we need to be
|
|
|
+ // alive when that callback is invoked.
|
|
|
+ if (lb_channel_ != nullptr) {
|
|
|
+ gpr_mu_lock(&lb_channel_mu_);
|
|
|
+ grpc_channel_destroy(lb_channel_);
|
|
|
+ lb_channel_ = nullptr;
|
|
|
+ gpr_mu_unlock(&lb_channel_mu_);
|
|
|
+ }
|
|
|
+ grpc_connectivity_state_set(&state_tracker_, GRPC_CHANNEL_SHUTDOWN,
|
|
|
+ GRPC_ERROR_REF(error), "grpclb_shutdown");
|
|
|
+ // Clear pending picks.
|
|
|
+ PendingPick* pp;
|
|
|
+ while ((pp = pending_picks_) != nullptr) {
|
|
|
+ pending_picks_ = pp->next;
|
|
|
+ pp->pick->connected_subchannel.reset();
|
|
|
+ // Note: pp is deleted in this callback.
|
|
|
+ GRPC_CLOSURE_SCHED(&pp->on_complete, GRPC_ERROR_REF(error));
|
|
|
+ }
|
|
|
+ GRPC_ERROR_UNREF(error);
|
|
|
+}
|
|
|
+
|
|
|
+//
|
|
|
+// public methods
|
|
|
+//
|
|
|
+
|
|
|
+void XdsLb::HandOffPendingPicksLocked(LoadBalancingPolicy* new_policy) {
|
|
|
+ PendingPick* pp;
|
|
|
+ while ((pp = pending_picks_) != nullptr) {
|
|
|
+ pending_picks_ = pp->next;
|
|
|
+ pp->pick->on_complete = pp->original_on_complete;
|
|
|
+ pp->pick->user_data = nullptr;
|
|
|
+ grpc_error* error = GRPC_ERROR_NONE;
|
|
|
+ if (new_policy->PickLocked(pp->pick, &error)) {
|
|
|
+ // Synchronous return; schedule closure.
|
|
|
+ GRPC_CLOSURE_SCHED(pp->pick->on_complete, error);
|
|
|
+ }
|
|
|
+ Delete(pp);
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+// Cancel a specific pending pick.
|
|
|
+//
|
|
|
+// A grpclb pick progresses as follows:
|
|
|
+// - If there's a Round Robin policy (rr_policy_) available, it'll be
|
|
|
+// handed over to the RR policy (in CreateRoundRobinPolicyLocked()). From
|
|
|
+// that point onwards, it'll be RR's responsibility. For cancellations, that
|
|
|
+// implies the pick needs also be cancelled by the RR instance.
|
|
|
+// - Otherwise, without an RR instance, picks stay pending at this policy's
|
|
|
+// level (grpclb), inside the pending_picks_ list. To cancel these,
|
|
|
+// we invoke the completion closure and set the pick's connected
|
|
|
+// subchannel to nullptr right here.
|
|
|
+void XdsLb::CancelPickLocked(PickState* pick, grpc_error* error) {
|
|
|
+ PendingPick* pp = pending_picks_;
|
|
|
+ pending_picks_ = nullptr;
|
|
|
+ while (pp != nullptr) {
|
|
|
+ PendingPick* next = pp->next;
|
|
|
+ if (pp->pick == pick) {
|
|
|
+ pick->connected_subchannel.reset();
|
|
|
+ // Note: pp is deleted in this callback.
|
|
|
+ GRPC_CLOSURE_SCHED(&pp->on_complete,
|
|
|
+ GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
|
|
|
+ "Pick Cancelled", &error, 1));
|
|
|
+ } else {
|
|
|
+ pp->next = pending_picks_;
|
|
|
+ pending_picks_ = pp;
|
|
|
+ }
|
|
|
+ pp = next;
|
|
|
+ }
|
|
|
+ if (rr_policy_ != nullptr) {
|
|
|
+ rr_policy_->CancelPickLocked(pick, GRPC_ERROR_REF(error));
|
|
|
+ }
|
|
|
+ GRPC_ERROR_UNREF(error);
|
|
|
+}
|
|
|
+
|
|
|
+// Cancel all pending picks.
|
|
|
+//
|
|
|
+// A grpclb pick progresses as follows:
|
|
|
+// - If there's a Round Robin policy (rr_policy_) available, it'll be
|
|
|
+// handed over to the RR policy (in CreateRoundRobinPolicyLocked()). From
|
|
|
+// that point onwards, it'll be RR's responsibility. For cancellations, that
|
|
|
+// implies the pick needs also be cancelled by the RR instance.
|
|
|
+// - Otherwise, without an RR instance, picks stay pending at this policy's
|
|
|
+// level (grpclb), inside the pending_picks_ list. To cancel these,
|
|
|
+// we invoke the completion closure and set the pick's connected
|
|
|
+// subchannel to nullptr right here.
|
|
|
+void XdsLb::CancelMatchingPicksLocked(uint32_t initial_metadata_flags_mask,
|
|
|
+ uint32_t initial_metadata_flags_eq,
|
|
|
+ grpc_error* error) {
|
|
|
+ PendingPick* pp = pending_picks_;
|
|
|
+ pending_picks_ = nullptr;
|
|
|
+ while (pp != nullptr) {
|
|
|
+ PendingPick* next = pp->next;
|
|
|
+ if ((pp->pick->initial_metadata_flags & initial_metadata_flags_mask) ==
|
|
|
+ initial_metadata_flags_eq) {
|
|
|
+ // Note: pp is deleted in this callback.
|
|
|
+ GRPC_CLOSURE_SCHED(&pp->on_complete,
|
|
|
+ GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
|
|
|
+ "Pick Cancelled", &error, 1));
|
|
|
+ } else {
|
|
|
+ pp->next = pending_picks_;
|
|
|
+ pending_picks_ = pp;
|
|
|
+ }
|
|
|
+ pp = next;
|
|
|
+ }
|
|
|
+ if (rr_policy_ != nullptr) {
|
|
|
+ rr_policy_->CancelMatchingPicksLocked(initial_metadata_flags_mask,
|
|
|
+ initial_metadata_flags_eq,
|
|
|
+ GRPC_ERROR_REF(error));
|
|
|
+ }
|
|
|
+ GRPC_ERROR_UNREF(error);
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::ExitIdleLocked() {
|
|
|
+ if (!started_picking_) {
|
|
|
+ StartPickingLocked();
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::ResetBackoffLocked() {
|
|
|
+ if (lb_channel_ != nullptr) {
|
|
|
+ grpc_channel_reset_connect_backoff(lb_channel_);
|
|
|
+ }
|
|
|
+ if (rr_policy_ != nullptr) {
|
|
|
+ rr_policy_->ResetBackoffLocked();
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+bool XdsLb::PickLocked(PickState* pick, grpc_error** error) {
|
|
|
+ PendingPick* pp = PendingPickCreate(pick);
|
|
|
+ bool pick_done = false;
|
|
|
+ if (rr_policy_ != nullptr) {
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] about to PICK from RR %p", this,
|
|
|
+ rr_policy_.get());
|
|
|
+ }
|
|
|
+ pick_done =
|
|
|
+ PickFromRoundRobinPolicyLocked(false /* force_async */, pp, error);
|
|
|
+ } else { // rr_policy_ == NULL
|
|
|
+ if (pick->on_complete == nullptr) {
|
|
|
+ *error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
|
|
|
+ "No pick result available but synchronous result required.");
|
|
|
+ pick_done = true;
|
|
|
+ } else {
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO,
|
|
|
+ "[xdslb %p] No RR policy. Adding to grpclb's pending picks",
|
|
|
+ this);
|
|
|
+ }
|
|
|
+ AddPendingPick(pp);
|
|
|
+ if (!started_picking_) {
|
|
|
+ StartPickingLocked();
|
|
|
+ }
|
|
|
+ pick_done = false;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return pick_done;
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::FillChildRefsForChannelz(channelz::ChildRefsList* child_subchannels,
|
|
|
+ channelz::ChildRefsList* child_channels) {
|
|
|
+ // delegate to the RoundRobin to fill the children subchannels.
|
|
|
+ rr_policy_->FillChildRefsForChannelz(child_subchannels, child_channels);
|
|
|
+ MutexLock lock(&lb_channel_mu_);
|
|
|
+ if (lb_channel_ != nullptr) {
|
|
|
+ grpc_core::channelz::ChannelNode* channel_node =
|
|
|
+ grpc_channel_get_channelz_node(lb_channel_);
|
|
|
+ if (channel_node != nullptr) {
|
|
|
+ child_channels->push_back(channel_node->uuid());
|
|
|
+ }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+grpc_connectivity_state XdsLb::CheckConnectivityLocked(
|
|
|
+ grpc_error** connectivity_error) {
|
|
|
+ return grpc_connectivity_state_get(&state_tracker_, connectivity_error);
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::NotifyOnStateChangeLocked(grpc_connectivity_state* current,
|
|
|
+ grpc_closure* closure) {
|
|
|
+ grpc_connectivity_state_notify_on_state_change(&state_tracker_, current,
|
|
|
+ closure);
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::ProcessChannelArgsLocked(const grpc_channel_args& args) {
|
|
|
+ const grpc_arg* arg = grpc_channel_args_find(&args, GRPC_ARG_LB_ADDRESSES);
|
|
|
+ if (GPR_UNLIKELY(arg == nullptr || arg->type != GRPC_ARG_POINTER)) {
|
|
|
+ // Ignore this update.
|
|
|
+ gpr_log(GPR_ERROR,
|
|
|
+ "[xdslb %p] No valid LB addresses channel arg in update, ignoring.",
|
|
|
+ this);
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ const grpc_lb_addresses* addresses =
|
|
|
+ static_cast<const grpc_lb_addresses*>(arg->value.pointer.p);
|
|
|
+ // Update fallback address list.
|
|
|
+ if (fallback_backend_addresses_ != nullptr) {
|
|
|
+ grpc_lb_addresses_destroy(fallback_backend_addresses_);
|
|
|
+ }
|
|
|
+ fallback_backend_addresses_ = ExtractBackendAddresses(addresses);
|
|
|
+ // Make sure that GRPC_ARG_LB_POLICY_NAME is set in channel args,
|
|
|
+ // since we use this to trigger the client_load_reporting filter.
|
|
|
+ static const char* args_to_remove[] = {GRPC_ARG_LB_POLICY_NAME};
|
|
|
+ grpc_arg new_arg = grpc_channel_arg_string_create(
|
|
|
+ (char*)GRPC_ARG_LB_POLICY_NAME, (char*)"xds");
|
|
|
+ grpc_channel_args_destroy(args_);
|
|
|
+ args_ = grpc_channel_args_copy_and_add_and_remove(
|
|
|
+ &args, args_to_remove, GPR_ARRAY_SIZE(args_to_remove), &new_arg, 1);
|
|
|
+ // Construct args for balancer channel.
|
|
|
+ grpc_channel_args* lb_channel_args =
|
|
|
+ BuildBalancerChannelArgs(addresses, response_generator_.get(), &args);
|
|
|
+ // Create balancer channel if needed.
|
|
|
+ if (lb_channel_ == nullptr) {
|
|
|
+ char* uri_str;
|
|
|
+ gpr_asprintf(&uri_str, "fake:///%s", server_name_);
|
|
|
+ gpr_mu_lock(&lb_channel_mu_);
|
|
|
+ lb_channel_ = grpc_client_channel_factory_create_channel(
|
|
|
+ client_channel_factory(), uri_str,
|
|
|
+ GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, lb_channel_args);
|
|
|
+ gpr_mu_unlock(&lb_channel_mu_);
|
|
|
+ GPR_ASSERT(lb_channel_ != nullptr);
|
|
|
+ gpr_free(uri_str);
|
|
|
+ }
|
|
|
+ // Propagate updates to the LB channel (pick_first) through the fake
|
|
|
+ // resolver.
|
|
|
+ response_generator_->SetResponse(lb_channel_args);
|
|
|
+ grpc_channel_args_destroy(lb_channel_args);
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::UpdateLocked(const grpc_channel_args& args) {
|
|
|
+ ProcessChannelArgsLocked(args);
|
|
|
+ // If fallback is configured and the RR policy already exists, update
|
|
|
+ // it with the new fallback addresses.
|
|
|
+ if (lb_fallback_timeout_ms_ > 0 && rr_policy_ != nullptr) {
|
|
|
+ CreateOrUpdateRoundRobinPolicyLocked();
|
|
|
+ }
|
|
|
+ // Start watching the LB channel connectivity for connection, if not
|
|
|
+ // already doing so.
|
|
|
+ if (!watching_lb_channel_) {
|
|
|
+ lb_channel_connectivity_ = grpc_channel_check_connectivity_state(
|
|
|
+ lb_channel_, true /* try to connect */);
|
|
|
+ grpc_channel_element* client_channel_elem = grpc_channel_stack_last_element(
|
|
|
+ grpc_channel_get_channel_stack(lb_channel_));
|
|
|
+ GPR_ASSERT(client_channel_elem->filter == &grpc_client_channel_filter);
|
|
|
+ watching_lb_channel_ = true;
|
|
|
+ // TODO(roth): We currently track this ref manually. Once the
|
|
|
+ // ClosureRef API is ready, we should pass the RefCountedPtr<> along
|
|
|
+ // with the callback.
|
|
|
+ auto self = Ref(DEBUG_LOCATION, "watch_lb_channel_connectivity");
|
|
|
+ self.release();
|
|
|
+ grpc_client_channel_watch_connectivity_state(
|
|
|
+ client_channel_elem,
|
|
|
+ grpc_polling_entity_create_from_pollset_set(interested_parties()),
|
|
|
+ &lb_channel_connectivity_, &lb_channel_on_connectivity_changed_,
|
|
|
+ nullptr);
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+//
|
|
|
+// code for balancer channel and call
|
|
|
+//
|
|
|
+
|
|
|
+void XdsLb::StartPickingLocked() {
|
|
|
+ // Start a timer to fall back.
|
|
|
+ if (lb_fallback_timeout_ms_ > 0 && serverlist_ == nullptr &&
|
|
|
+ !fallback_timer_callback_pending_) {
|
|
|
+ grpc_millis deadline = ExecCtx::Get()->Now() + lb_fallback_timeout_ms_;
|
|
|
+ // TODO(roth): We currently track this ref manually. Once the
|
|
|
+ // ClosureRef API is ready, we should pass the RefCountedPtr<> along
|
|
|
+ // with the callback.
|
|
|
+ auto self = Ref(DEBUG_LOCATION, "on_fallback_timer");
|
|
|
+ self.release();
|
|
|
+ GRPC_CLOSURE_INIT(&lb_on_fallback_, &XdsLb::OnFallbackTimerLocked, this,
|
|
|
+ grpc_combiner_scheduler(combiner()));
|
|
|
+ fallback_timer_callback_pending_ = true;
|
|
|
+ grpc_timer_init(&lb_fallback_timer_, deadline, &lb_on_fallback_);
|
|
|
+ }
|
|
|
+ started_picking_ = true;
|
|
|
+ StartBalancerCallLocked();
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::StartBalancerCallLocked() {
|
|
|
+ GPR_ASSERT(lb_channel_ != nullptr);
|
|
|
+ if (shutting_down_) return;
|
|
|
+ // Init the LB call data.
|
|
|
+ GPR_ASSERT(lb_calld_ == nullptr);
|
|
|
+ lb_calld_ = MakeOrphanable<BalancerCallState>(Ref());
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO,
|
|
|
+ "[xdslb %p] Query for backends (lb_channel: %p, lb_calld: %p)",
|
|
|
+ this, lb_channel_, lb_calld_.get());
|
|
|
+ }
|
|
|
+ lb_calld_->StartQuery();
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::OnFallbackTimerLocked(void* arg, grpc_error* error) {
|
|
|
+ XdsLb* xdslb_policy = static_cast<XdsLb*>(arg);
|
|
|
+ xdslb_policy->fallback_timer_callback_pending_ = false;
|
|
|
+ // If we receive a serverlist after the timer fires but before this callback
|
|
|
+ // actually runs, don't fall back.
|
|
|
+ if (xdslb_policy->serverlist_ == nullptr && !xdslb_policy->shutting_down_ &&
|
|
|
+ error == GRPC_ERROR_NONE) {
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] Falling back to use backends from resolver",
|
|
|
+ xdslb_policy);
|
|
|
+ }
|
|
|
+ GPR_ASSERT(xdslb_policy->fallback_backend_addresses_ != nullptr);
|
|
|
+ xdslb_policy->CreateOrUpdateRoundRobinPolicyLocked();
|
|
|
+ }
|
|
|
+ xdslb_policy->Unref(DEBUG_LOCATION, "on_fallback_timer");
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::StartBalancerCallRetryTimerLocked() {
|
|
|
+ grpc_millis next_try = lb_call_backoff_.NextAttemptTime();
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] Connection to LB server lost...", this);
|
|
|
+ grpc_millis timeout = next_try - ExecCtx::Get()->Now();
|
|
|
+ if (timeout > 0) {
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] ... retry_timer_active in %" PRId64 "ms.",
|
|
|
+ this, timeout);
|
|
|
+ } else {
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] ... retry_timer_active immediately.", this);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ // TODO(roth): We currently track this ref manually. Once the
|
|
|
+ // ClosureRef API is ready, we should pass the RefCountedPtr<> along
|
|
|
+ // with the callback.
|
|
|
+ auto self = Ref(DEBUG_LOCATION, "on_balancer_call_retry_timer");
|
|
|
+ self.release();
|
|
|
+ GRPC_CLOSURE_INIT(&lb_on_call_retry_, &XdsLb::OnBalancerCallRetryTimerLocked,
|
|
|
+ this, grpc_combiner_scheduler(combiner()));
|
|
|
+ retry_timer_callback_pending_ = true;
|
|
|
+ grpc_timer_init(&lb_call_retry_timer_, next_try, &lb_on_call_retry_);
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::OnBalancerCallRetryTimerLocked(void* arg, grpc_error* error) {
|
|
|
+ XdsLb* xdslb_policy = static_cast<XdsLb*>(arg);
|
|
|
+ xdslb_policy->retry_timer_callback_pending_ = false;
|
|
|
+ if (!xdslb_policy->shutting_down_ && error == GRPC_ERROR_NONE &&
|
|
|
+ xdslb_policy->lb_calld_ == nullptr) {
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] Restarting call to LB server",
|
|
|
+ xdslb_policy);
|
|
|
+ }
|
|
|
+ xdslb_policy->StartBalancerCallLocked();
|
|
|
+ }
|
|
|
+ xdslb_policy->Unref(DEBUG_LOCATION, "on_balancer_call_retry_timer");
|
|
|
+}
|
|
|
+
|
|
|
+// Invoked as part of the update process. It continues watching the LB channel
|
|
|
+// until it shuts down or becomes READY. It's invoked even if the LB channel
|
|
|
+// stayed READY throughout the update (for example if the update is identical).
|
|
|
+void XdsLb::OnBalancerChannelConnectivityChangedLocked(void* arg,
|
|
|
+ grpc_error* error) {
|
|
|
+ XdsLb* xdslb_policy = static_cast<XdsLb*>(arg);
|
|
|
+ if (xdslb_policy->shutting_down_) goto done;
|
|
|
+ // Re-initialize the lb_call. This should also take care of updating the
|
|
|
+ // embedded RR policy. Note that the current RR policy, if any, will stay in
|
|
|
+ // effect until an update from the new lb_call is received.
|
|
|
+ switch (xdslb_policy->lb_channel_connectivity_) {
|
|
|
+ case GRPC_CHANNEL_CONNECTING:
|
|
|
+ case GRPC_CHANNEL_TRANSIENT_FAILURE: {
|
|
|
+ // Keep watching the LB channel.
|
|
|
+ grpc_channel_element* client_channel_elem =
|
|
|
+ grpc_channel_stack_last_element(
|
|
|
+ grpc_channel_get_channel_stack(xdslb_policy->lb_channel_));
|
|
|
+ GPR_ASSERT(client_channel_elem->filter == &grpc_client_channel_filter);
|
|
|
+ grpc_client_channel_watch_connectivity_state(
|
|
|
+ client_channel_elem,
|
|
|
+ grpc_polling_entity_create_from_pollset_set(
|
|
|
+ xdslb_policy->interested_parties()),
|
|
|
+ &xdslb_policy->lb_channel_connectivity_,
|
|
|
+ &xdslb_policy->lb_channel_on_connectivity_changed_, nullptr);
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ // The LB channel may be IDLE because it's shut down before the update.
|
|
|
+ // Restart the LB call to kick the LB channel into gear.
|
|
|
+ case GRPC_CHANNEL_IDLE:
|
|
|
+ case GRPC_CHANNEL_READY:
|
|
|
+ xdslb_policy->lb_calld_.reset();
|
|
|
+ if (xdslb_policy->started_picking_) {
|
|
|
+ if (xdslb_policy->retry_timer_callback_pending_) {
|
|
|
+ grpc_timer_cancel(&xdslb_policy->lb_call_retry_timer_);
|
|
|
+ }
|
|
|
+ xdslb_policy->lb_call_backoff_.Reset();
|
|
|
+ xdslb_policy->StartBalancerCallLocked();
|
|
|
+ }
|
|
|
+ [[fallthrough]];
|
|
|
+ // Fall through.
|
|
|
+ case GRPC_CHANNEL_SHUTDOWN:
|
|
|
+ done:
|
|
|
+ xdslb_policy->watching_lb_channel_ = false;
|
|
|
+ xdslb_policy->Unref(DEBUG_LOCATION,
|
|
|
+ "watch_lb_channel_connectivity_cb_shutdown");
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+//
|
|
|
+// PendingPick
|
|
|
+//
|
|
|
+
|
|
|
+// Adds lb_token of selected subchannel (address) to the call's initial
|
|
|
+// metadata.
|
|
|
+grpc_error* AddLbTokenToInitialMetadata(
|
|
|
+ grpc_mdelem lb_token, grpc_linked_mdelem* lb_token_mdelem_storage,
|
|
|
+ grpc_metadata_batch* initial_metadata) {
|
|
|
+ GPR_ASSERT(lb_token_mdelem_storage != nullptr);
|
|
|
+ GPR_ASSERT(!GRPC_MDISNULL(lb_token));
|
|
|
+ return grpc_metadata_batch_add_tail(initial_metadata, lb_token_mdelem_storage,
|
|
|
+ lb_token);
|
|
|
+}
|
|
|
+
|
|
|
+// Destroy function used when embedding client stats in call context.
|
|
|
+void DestroyClientStats(void* arg) {
|
|
|
+ static_cast<XdsLbClientStats*>(arg)->Unref();
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::PendingPickSetMetadataAndContext(PendingPick* pp) {
|
|
|
+ /* if connected_subchannel is nullptr, no pick has been made by the RR
|
|
|
+ * policy (e.g., all addresses failed to connect). There won't be any
|
|
|
+ * user_data/token available */
|
|
|
+ if (pp->pick->connected_subchannel != nullptr) {
|
|
|
+ if (GPR_LIKELY(!GRPC_MDISNULL(pp->lb_token))) {
|
|
|
+ AddLbTokenToInitialMetadata(GRPC_MDELEM_REF(pp->lb_token),
|
|
|
+ &pp->pick->lb_token_mdelem_storage,
|
|
|
+ pp->pick->initial_metadata);
|
|
|
+ } else {
|
|
|
+ gpr_log(GPR_ERROR,
|
|
|
+ "[xdslb %p] No LB token for connected subchannel pick %p",
|
|
|
+ pp->xdslb_policy, pp->pick);
|
|
|
+ abort();
|
|
|
+ }
|
|
|
+ // Pass on client stats via context. Passes ownership of the reference.
|
|
|
+ if (pp->client_stats != nullptr) {
|
|
|
+ pp->pick->subchannel_call_context[GRPC_GRPCLB_CLIENT_STATS].value =
|
|
|
+ pp->client_stats.release();
|
|
|
+ pp->pick->subchannel_call_context[GRPC_GRPCLB_CLIENT_STATS].destroy =
|
|
|
+ DestroyClientStats;
|
|
|
+ }
|
|
|
+ } else {
|
|
|
+ pp->client_stats.reset();
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+/* The \a on_complete closure passed as part of the pick requires keeping a
|
|
|
+ * reference to its associated round robin instance. We wrap this closure in
|
|
|
+ * order to unref the round robin instance upon its invocation */
|
|
|
+void XdsLb::OnPendingPickComplete(void* arg, grpc_error* error) {
|
|
|
+ PendingPick* pp = static_cast<PendingPick*>(arg);
|
|
|
+ PendingPickSetMetadataAndContext(pp);
|
|
|
+ GRPC_CLOSURE_SCHED(pp->original_on_complete, GRPC_ERROR_REF(error));
|
|
|
+ Delete(pp);
|
|
|
+}
|
|
|
+
|
|
|
+XdsLb::PendingPick* XdsLb::PendingPickCreate(PickState* pick) {
|
|
|
+ PendingPick* pp = New<PendingPick>();
|
|
|
+ pp->xdslb_policy = this;
|
|
|
+ pp->pick = pick;
|
|
|
+ GRPC_CLOSURE_INIT(&pp->on_complete, &XdsLb::OnPendingPickComplete, pp,
|
|
|
+ grpc_schedule_on_exec_ctx);
|
|
|
+ pp->original_on_complete = pick->on_complete;
|
|
|
+ pick->on_complete = &pp->on_complete;
|
|
|
+ return pp;
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::AddPendingPick(PendingPick* pp) {
|
|
|
+ pp->next = pending_picks_;
|
|
|
+ pending_picks_ = pp;
|
|
|
+}
|
|
|
+
|
|
|
+//
|
|
|
+// code for interacting with the RR policy
|
|
|
+//
|
|
|
+
|
|
|
+// Performs a pick over \a rr_policy_. Given that a pick can return
|
|
|
+// immediately (ignoring its completion callback), we need to perform the
|
|
|
+// cleanups this callback would otherwise be responsible for.
|
|
|
+// If \a force_async is true, then we will manually schedule the
|
|
|
+// completion callback even if the pick is available immediately.
|
|
|
+bool XdsLb::PickFromRoundRobinPolicyLocked(bool force_async, PendingPick* pp,
|
|
|
+ grpc_error** error) {
|
|
|
+ // Check for drops if we are not using fallback backend addresses.
|
|
|
+ if (serverlist_ != nullptr) {
|
|
|
+ // Look at the index into the serverlist to see if we should drop this call.
|
|
|
+ xds_grpclb_server* server = serverlist_->servers[serverlist_index_++];
|
|
|
+ if (serverlist_index_ == serverlist_->num_servers) {
|
|
|
+ serverlist_index_ = 0; // Wrap-around.
|
|
|
+ }
|
|
|
+ if (server->drop) {
|
|
|
+ // Update client load reporting stats to indicate the number of
|
|
|
+ // dropped calls. Note that we have to do this here instead of in
|
|
|
+ // the client_load_reporting filter, because we do not create a
|
|
|
+ // subchannel call (and therefore no client_load_reporting filter)
|
|
|
+ // for dropped calls.
|
|
|
+ if (lb_calld_ != nullptr && lb_calld_->client_stats() != nullptr) {
|
|
|
+ lb_calld_->client_stats()->AddCallDroppedLocked(
|
|
|
+ server->load_balance_token);
|
|
|
+ }
|
|
|
+ if (force_async) {
|
|
|
+ GRPC_CLOSURE_SCHED(pp->original_on_complete, GRPC_ERROR_NONE);
|
|
|
+ Delete(pp);
|
|
|
+ return false;
|
|
|
+ }
|
|
|
+ Delete(pp);
|
|
|
+ return true;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ // Set client_stats and user_data.
|
|
|
+ if (lb_calld_ != nullptr && lb_calld_->client_stats() != nullptr) {
|
|
|
+ pp->client_stats = lb_calld_->client_stats()->Ref();
|
|
|
+ }
|
|
|
+ GPR_ASSERT(pp->pick->user_data == nullptr);
|
|
|
+ pp->pick->user_data = (void**)&pp->lb_token;
|
|
|
+ // Pick via the RR policy.
|
|
|
+ bool pick_done = rr_policy_->PickLocked(pp->pick, error);
|
|
|
+ if (pick_done) {
|
|
|
+ PendingPickSetMetadataAndContext(pp);
|
|
|
+ if (force_async) {
|
|
|
+ GRPC_CLOSURE_SCHED(pp->original_on_complete, *error);
|
|
|
+ *error = GRPC_ERROR_NONE;
|
|
|
+ pick_done = false;
|
|
|
+ }
|
|
|
+ Delete(pp);
|
|
|
+ }
|
|
|
+ // else, the pending pick will be registered and taken care of by the
|
|
|
+ // pending pick list inside the RR policy. Eventually,
|
|
|
+ // OnPendingPickComplete() will be called, which will (among other
|
|
|
+ // things) add the LB token to the call's initial metadata.
|
|
|
+ return pick_done;
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::CreateRoundRobinPolicyLocked(const Args& args) {
|
|
|
+ GPR_ASSERT(rr_policy_ == nullptr);
|
|
|
+ rr_policy_ = LoadBalancingPolicyRegistry::CreateLoadBalancingPolicy(
|
|
|
+ "round_robin", args);
|
|
|
+ if (GPR_UNLIKELY(rr_policy_ == nullptr)) {
|
|
|
+ gpr_log(GPR_ERROR, "[xdslb %p] Failure creating a RoundRobin policy", this);
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ // TODO(roth): We currently track this ref manually. Once the new
|
|
|
+ // ClosureRef API is done, pass the RefCountedPtr<> along with the closure.
|
|
|
+ auto self = Ref(DEBUG_LOCATION, "on_rr_reresolution_requested");
|
|
|
+ self.release();
|
|
|
+ rr_policy_->SetReresolutionClosureLocked(&on_rr_request_reresolution_);
|
|
|
+ grpc_error* rr_state_error = nullptr;
|
|
|
+ rr_connectivity_state_ = rr_policy_->CheckConnectivityLocked(&rr_state_error);
|
|
|
+ // Connectivity state is a function of the RR policy updated/created.
|
|
|
+ UpdateConnectivityStateFromRoundRobinPolicyLocked(rr_state_error);
|
|
|
+ // Add the gRPC LB's interested_parties pollset_set to that of the newly
|
|
|
+ // created RR policy. This will make the RR policy progress upon activity on
|
|
|
+ // gRPC LB, which in turn is tied to the application's call.
|
|
|
+ grpc_pollset_set_add_pollset_set(rr_policy_->interested_parties(),
|
|
|
+ interested_parties());
|
|
|
+ // Subscribe to changes to the connectivity of the new RR.
|
|
|
+ // TODO(roth): We currently track this ref manually. Once the new
|
|
|
+ // ClosureRef API is done, pass the RefCountedPtr<> along with the closure.
|
|
|
+ self = Ref(DEBUG_LOCATION, "on_rr_connectivity_changed");
|
|
|
+ self.release();
|
|
|
+ rr_policy_->NotifyOnStateChangeLocked(&rr_connectivity_state_,
|
|
|
+ &on_rr_connectivity_changed_);
|
|
|
+ rr_policy_->ExitIdleLocked();
|
|
|
+ // Send pending picks to RR policy.
|
|
|
+ PendingPick* pp;
|
|
|
+ while ((pp = pending_picks_)) {
|
|
|
+ pending_picks_ = pp->next;
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO,
|
|
|
+ "[xdslb %p] Pending pick about to (async) PICK from RR %p", this,
|
|
|
+ rr_policy_.get());
|
|
|
+ }
|
|
|
+ grpc_error* error = GRPC_ERROR_NONE;
|
|
|
+ PickFromRoundRobinPolicyLocked(true /* force_async */, pp, &error);
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+grpc_channel_args* XdsLb::CreateRoundRobinPolicyArgsLocked() {
|
|
|
+ grpc_lb_addresses* addresses;
|
|
|
+ bool is_backend_from_grpclb_load_balancer = false;
|
|
|
+ if (serverlist_ != nullptr) {
|
|
|
+ GPR_ASSERT(serverlist_->num_servers > 0);
|
|
|
+ addresses = ProcessServerlist(serverlist_);
|
|
|
+ is_backend_from_grpclb_load_balancer = true;
|
|
|
+ } else {
|
|
|
+ // If CreateOrUpdateRoundRobinPolicyLocked() is invoked when we haven't
|
|
|
+ // received any serverlist from the balancer, we use the fallback backends
|
|
|
+ // returned by the resolver. Note that the fallback backend list may be
|
|
|
+ // empty, in which case the new round_robin policy will keep the requested
|
|
|
+ // picks pending.
|
|
|
+ GPR_ASSERT(fallback_backend_addresses_ != nullptr);
|
|
|
+ addresses = grpc_lb_addresses_copy(fallback_backend_addresses_);
|
|
|
+ }
|
|
|
+ GPR_ASSERT(addresses != nullptr);
|
|
|
+ // Replace the LB addresses in the channel args that we pass down to
|
|
|
+ // the subchannel.
|
|
|
+ static const char* keys_to_remove[] = {GRPC_ARG_LB_ADDRESSES};
|
|
|
+ const grpc_arg args_to_add[] = {
|
|
|
+ grpc_lb_addresses_create_channel_arg(addresses),
|
|
|
+ // A channel arg indicating if the target is a backend inferred from a
|
|
|
+ // grpclb load balancer.
|
|
|
+ grpc_channel_arg_integer_create(
|
|
|
+ const_cast<char*>(GRPC_ARG_ADDRESS_IS_BACKEND_FROM_XDS_LOAD_BALANCER),
|
|
|
+ is_backend_from_grpclb_load_balancer),
|
|
|
+ };
|
|
|
+ grpc_channel_args* args = grpc_channel_args_copy_and_add_and_remove(
|
|
|
+ args_, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), args_to_add,
|
|
|
+ GPR_ARRAY_SIZE(args_to_add));
|
|
|
+ grpc_lb_addresses_destroy(addresses);
|
|
|
+ return args;
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::CreateOrUpdateRoundRobinPolicyLocked() {
|
|
|
+ if (shutting_down_) return;
|
|
|
+ grpc_channel_args* args = CreateRoundRobinPolicyArgsLocked();
|
|
|
+ GPR_ASSERT(args != nullptr);
|
|
|
+ if (rr_policy_ != nullptr) {
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] Updating RR policy %p", this,
|
|
|
+ rr_policy_.get());
|
|
|
+ }
|
|
|
+ rr_policy_->UpdateLocked(*args);
|
|
|
+ } else {
|
|
|
+ LoadBalancingPolicy::Args lb_policy_args;
|
|
|
+ lb_policy_args.combiner = combiner();
|
|
|
+ lb_policy_args.client_channel_factory = client_channel_factory();
|
|
|
+ lb_policy_args.args = args;
|
|
|
+ CreateRoundRobinPolicyLocked(lb_policy_args);
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(GPR_INFO, "[xdslb %p] Created new RR policy %p", this,
|
|
|
+ rr_policy_.get());
|
|
|
+ }
|
|
|
+ }
|
|
|
+ grpc_channel_args_destroy(args);
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::OnRoundRobinRequestReresolutionLocked(void* arg,
|
|
|
+ grpc_error* error) {
|
|
|
+ XdsLb* xdslb_policy = static_cast<XdsLb*>(arg);
|
|
|
+ if (xdslb_policy->shutting_down_ || error != GRPC_ERROR_NONE) {
|
|
|
+ xdslb_policy->Unref(DEBUG_LOCATION, "on_rr_reresolution_requested");
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(
|
|
|
+ GPR_INFO,
|
|
|
+ "[xdslb %p] Re-resolution requested from the internal RR policy (%p).",
|
|
|
+ xdslb_policy, xdslb_policy->rr_policy_.get());
|
|
|
+ }
|
|
|
+ // If we are talking to a balancer, we expect to get updated addresses form
|
|
|
+ // the balancer, so we can ignore the re-resolution request from the RR
|
|
|
+ // policy. Otherwise, handle the re-resolution request using the
|
|
|
+ // grpclb policy's original re-resolution closure.
|
|
|
+ if (xdslb_policy->lb_calld_ == nullptr ||
|
|
|
+ !xdslb_policy->lb_calld_->seen_initial_response()) {
|
|
|
+ xdslb_policy->TryReresolutionLocked(&grpc_lb_xds_trace, GRPC_ERROR_NONE);
|
|
|
+ }
|
|
|
+ // Give back the wrapper closure to the RR policy.
|
|
|
+ xdslb_policy->rr_policy_->SetReresolutionClosureLocked(
|
|
|
+ &xdslb_policy->on_rr_request_reresolution_);
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::UpdateConnectivityStateFromRoundRobinPolicyLocked(
|
|
|
+ grpc_error* rr_state_error) {
|
|
|
+ const grpc_connectivity_state curr_glb_state =
|
|
|
+ grpc_connectivity_state_check(&state_tracker_);
|
|
|
+ /* The new connectivity status is a function of the previous one and the new
|
|
|
+ * input coming from the status of the RR policy.
|
|
|
+ *
|
|
|
+ * current state (grpclb's)
|
|
|
+ * |
|
|
|
+ * v || I | C | R | TF | SD | <- new state (RR's)
|
|
|
+ * ===++====+=====+=====+======+======+
|
|
|
+ * I || I | C | R | [I] | [I] |
|
|
|
+ * ---++----+-----+-----+------+------+
|
|
|
+ * C || I | C | R | [C] | [C] |
|
|
|
+ * ---++----+-----+-----+------+------+
|
|
|
+ * R || I | C | R | [R] | [R] |
|
|
|
+ * ---++----+-----+-----+------+------+
|
|
|
+ * TF || I | C | R | [TF] | [TF] |
|
|
|
+ * ---++----+-----+-----+------+------+
|
|
|
+ * SD || NA | NA | NA | NA | NA | (*)
|
|
|
+ * ---++----+-----+-----+------+------+
|
|
|
+ *
|
|
|
+ * A [STATE] indicates that the old RR policy is kept. In those cases, STATE
|
|
|
+ * is the current state of grpclb, which is left untouched.
|
|
|
+ *
|
|
|
+ * In summary, if the new state is TRANSIENT_FAILURE or SHUTDOWN, stick to
|
|
|
+ * the previous RR instance.
|
|
|
+ *
|
|
|
+ * Note that the status is never updated to SHUTDOWN as a result of calling
|
|
|
+ * this function. Only glb_shutdown() has the power to set that state.
|
|
|
+ *
|
|
|
+ * (*) This function mustn't be called during shutting down. */
|
|
|
+ GPR_ASSERT(curr_glb_state != GRPC_CHANNEL_SHUTDOWN);
|
|
|
+ switch (rr_connectivity_state_) {
|
|
|
+ case GRPC_CHANNEL_TRANSIENT_FAILURE:
|
|
|
+ case GRPC_CHANNEL_SHUTDOWN:
|
|
|
+ GPR_ASSERT(rr_state_error != GRPC_ERROR_NONE);
|
|
|
+ break;
|
|
|
+ case GRPC_CHANNEL_IDLE:
|
|
|
+ case GRPC_CHANNEL_CONNECTING:
|
|
|
+ case GRPC_CHANNEL_READY:
|
|
|
+ GPR_ASSERT(rr_state_error == GRPC_ERROR_NONE);
|
|
|
+ }
|
|
|
+ if (grpc_lb_xds_trace.enabled()) {
|
|
|
+ gpr_log(
|
|
|
+ GPR_INFO,
|
|
|
+ "[xdslb %p] Setting grpclb's state to %s from new RR policy %p state.",
|
|
|
+ this, grpc_connectivity_state_name(rr_connectivity_state_),
|
|
|
+ rr_policy_.get());
|
|
|
+ }
|
|
|
+ grpc_connectivity_state_set(&state_tracker_, rr_connectivity_state_,
|
|
|
+ rr_state_error,
|
|
|
+ "update_lb_connectivity_status_locked");
|
|
|
+}
|
|
|
+
|
|
|
+void XdsLb::OnRoundRobinConnectivityChangedLocked(void* arg,
|
|
|
+ grpc_error* error) {
|
|
|
+ XdsLb* xdslb_policy = static_cast<XdsLb*>(arg);
|
|
|
+ if (xdslb_policy->shutting_down_) {
|
|
|
+ xdslb_policy->Unref(DEBUG_LOCATION, "on_rr_connectivity_changed");
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ xdslb_policy->UpdateConnectivityStateFromRoundRobinPolicyLocked(
|
|
|
+ GRPC_ERROR_REF(error));
|
|
|
+ // Resubscribe. Reuse the "on_rr_connectivity_changed" ref.
|
|
|
+ xdslb_policy->rr_policy_->NotifyOnStateChangeLocked(
|
|
|
+ &xdslb_policy->rr_connectivity_state_,
|
|
|
+ &xdslb_policy->on_rr_connectivity_changed_);
|
|
|
+}
|
|
|
+
|
|
|
+//
|
|
|
+// factory
|
|
|
+//
|
|
|
+
|
|
|
+class XdsFactory : public LoadBalancingPolicyFactory {
|
|
|
+ public:
|
|
|
+ OrphanablePtr<LoadBalancingPolicy> CreateLoadBalancingPolicy(
|
|
|
+ const LoadBalancingPolicy::Args& args) const override {
|
|
|
+ /* Count the number of gRPC-LB addresses. There must be at least one. */
|
|
|
+ const grpc_arg* arg =
|
|
|
+ grpc_channel_args_find(args.args, GRPC_ARG_LB_ADDRESSES);
|
|
|
+ if (arg == nullptr || arg->type != GRPC_ARG_POINTER) {
|
|
|
+ return nullptr;
|
|
|
+ }
|
|
|
+ grpc_lb_addresses* addresses =
|
|
|
+ static_cast<grpc_lb_addresses*>(arg->value.pointer.p);
|
|
|
+ size_t num_grpclb_addrs = 0;
|
|
|
+ for (size_t i = 0; i < addresses->num_addresses; ++i) {
|
|
|
+ if (addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
|
|
|
+ }
|
|
|
+ if (num_grpclb_addrs == 0) return nullptr;
|
|
|
+ return OrphanablePtr<LoadBalancingPolicy>(New<XdsLb>(addresses, args));
|
|
|
+ }
|
|
|
+
|
|
|
+ const char* name() const override { return "xds"; }
|
|
|
+};
|
|
|
+
|
|
|
+} // namespace
|
|
|
+
|
|
|
+} // namespace grpc_core
|
|
|
+
|
|
|
+//
|
|
|
+// Plugin registration
|
|
|
+//
|
|
|
+
|
|
|
+namespace {
|
|
|
+
|
|
|
+// Only add client_load_reporting filter if the grpclb LB policy is used.
|
|
|
+bool maybe_add_client_load_reporting_filter(grpc_channel_stack_builder* builder,
|
|
|
+ void* arg) {
|
|
|
+ const grpc_channel_args* args =
|
|
|
+ grpc_channel_stack_builder_get_channel_arguments(builder);
|
|
|
+ const grpc_arg* channel_arg =
|
|
|
+ grpc_channel_args_find(args, GRPC_ARG_LB_POLICY_NAME);
|
|
|
+ if (channel_arg != nullptr && channel_arg->type == GRPC_ARG_STRING &&
|
|
|
+ strcmp(channel_arg->value.string, "grpclb") == 0) {
|
|
|
+ return grpc_channel_stack_builder_append_filter(
|
|
|
+ builder, (const grpc_channel_filter*)arg, nullptr, nullptr);
|
|
|
+ }
|
|
|
+ return true;
|
|
|
+}
|
|
|
+
|
|
|
+} // namespace
|
|
|
+
|
|
|
+void grpc_lb_policy_xds_init() {
|
|
|
+ grpc_core::LoadBalancingPolicyRegistry::Builder::
|
|
|
+ RegisterLoadBalancingPolicyFactory(
|
|
|
+ grpc_core::UniquePtr<grpc_core::LoadBalancingPolicyFactory>(
|
|
|
+ grpc_core::New<grpc_core::XdsFactory>()));
|
|
|
+ grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL,
|
|
|
+ GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
|
|
|
+ maybe_add_client_load_reporting_filter,
|
|
|
+ (void*)&xds_client_load_reporting_filter);
|
|
|
+}
|
|
|
+
|
|
|
+void grpc_lb_policy_xds_shutdown() {}
|
Muxi Yan