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@ -109,12 +109,20 @@ class RoundRobin : public LoadBalancingPolicy { |
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void* user_data() const { return user_data_; } |
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grpc_connectivity_state connectivity_state() const { |
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return last_connectivity_state_; |
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} |
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void UpdateConnectivityStateLocked( |
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grpc_connectivity_state connectivity_state, grpc_error* error); |
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private: |
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void ProcessConnectivityChangeLocked(grpc_error* error) override; |
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void ProcessConnectivityChangeLocked( |
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grpc_connectivity_state connectivity_state, grpc_error* error) override; |
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const grpc_lb_user_data_vtable* user_data_vtable_; |
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void* user_data_ = nullptr; |
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grpc_connectivity_state prev_connectivity_state_ = GRPC_CHANNEL_IDLE; |
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grpc_connectivity_state last_connectivity_state_ = GRPC_CHANNEL_IDLE; |
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}; |
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// A list of subchannels.
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@ -137,9 +145,6 @@ class RoundRobin : public LoadBalancingPolicy { |
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// Starts watching the subchannels in this list.
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void StartWatchingLocked(); |
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// Returns true if we have started watching.
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bool started_watching() const { return started_watching_; } |
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// Updates the counters of subchannels in each state when a
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// subchannel transitions from old_state to new_state.
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// transient_failure_error is the error that is reported when
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@ -158,7 +163,6 @@ class RoundRobin : public LoadBalancingPolicy { |
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void UpdateRoundRobinStateFromSubchannelStateCountsLocked(); |
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private: |
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bool started_watching_ = false; |
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size_t num_ready_ = 0; |
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size_t num_connecting_ = 0; |
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size_t num_transient_failure_ = 0; |
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@ -416,29 +420,16 @@ void RoundRobin::RoundRobinSubchannelList::StartWatchingLocked() { |
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if (num_subchannels() == 0) return; |
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// Check current state of each subchannel synchronously, since any
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// subchannel already used by some other channel may have a non-IDLE
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// state. This will invoke ProcessConnectivityChangeLocked() for each
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// subchannel whose state is not IDLE. However, because started_watching_
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// is still false, the code there will do two special things:
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//
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// - It will skip re-resolution for any subchannel in state
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// TRANSIENT_FAILURE, since doing this at start-watching-time would
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// cause us to enter an endless loop of re-resolution (i.e.,
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// re-resolution would cause a new update, and the new update would
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// immediately trigger a new re-resolution).
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//
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// - It will not call UpdateRoundRobinStateFromSubchannelStateCountsLocked();
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// instead, we call that here after all subchannels have been checked.
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// This allows us to act more intelligently based on the state of all
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// subchannels, rather than just acting on the first one. For example,
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// if there is more than one pending pick, this allows us to spread the
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// picks across all READY subchannels rather than sending them all to
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// the first subchannel that reports READY.
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// state.
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for (size_t i = 0; i < num_subchannels(); ++i) { |
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subchannel(i)->CheckConnectivityStateLocked(); |
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grpc_error* error = GRPC_ERROR_NONE; |
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grpc_connectivity_state state = |
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subchannel(i)->CheckConnectivityStateLocked(&error); |
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if (state != GRPC_CHANNEL_IDLE) { |
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subchannel(i)->UpdateConnectivityStateLocked(state, error); |
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} |
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} |
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// Now set started_watching_ to true and call
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// UpdateRoundRobinStateFromSubchannelStateCountsLocked().
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started_watching_ = true; |
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// Now set the LB policy's state based on the subchannels' states.
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UpdateRoundRobinStateFromSubchannelStateCountsLocked(); |
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// Start connectivity watch for each subchannel.
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for (size_t i = 0; i < num_subchannels(); i++) { |
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@ -544,8 +535,15 @@ void RoundRobin::RoundRobinSubchannelList:: |
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MaybeUpdateRoundRobinConnectivityStateLocked(); |
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} |
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void RoundRobin::RoundRobinSubchannelData::UpdateConnectivityStateLocked( |
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grpc_connectivity_state connectivity_state, grpc_error* error) { |
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subchannel_list()->UpdateStateCountersLocked( |
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last_connectivity_state_, connectivity_state, GRPC_ERROR_REF(error)); |
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last_connectivity_state_ = connectivity_state; |
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} |
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void RoundRobin::RoundRobinSubchannelData::ProcessConnectivityChangeLocked( |
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grpc_error* error) { |
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grpc_connectivity_state connectivity_state, grpc_error* error) { |
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RoundRobin* p = static_cast<RoundRobin*>(subchannel_list()->policy()); |
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if (grpc_lb_round_robin_trace.enabled()) { |
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gpr_log( |
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@ -556,8 +554,8 @@ void RoundRobin::RoundRobinSubchannelData::ProcessConnectivityChangeLocked( |
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"p->shutdown=%d sd->subchannel_list->shutting_down=%d error=%s", |
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p, subchannel(), subchannel_list(), Index(), |
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subchannel_list()->num_subchannels(), |
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grpc_connectivity_state_name(prev_connectivity_state_), |
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grpc_connectivity_state_name(connectivity_state()), p->shutdown_, |
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grpc_connectivity_state_name(last_connectivity_state_), |
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grpc_connectivity_state_name(connectivity_state), p->shutdown_, |
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subchannel_list()->shutting_down(), grpc_error_string(error)); |
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} |
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GPR_ASSERT(subchannel() != nullptr); |
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@ -566,8 +564,7 @@ void RoundRobin::RoundRobinSubchannelData::ProcessConnectivityChangeLocked( |
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// Otherwise, if the subchannel was already in state TRANSIENT_FAILURE
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// when the subchannel list was created, we'd wind up in a constant
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// loop of re-resolution.
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if (connectivity_state() == GRPC_CHANNEL_TRANSIENT_FAILURE && |
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subchannel_list()->started_watching()) { |
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if (connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) { |
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if (grpc_lb_round_robin_trace.enabled()) { |
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gpr_log(GPR_INFO, |
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"[RR %p] Subchannel %p has gone into TRANSIENT_FAILURE. " |
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@ -577,16 +574,11 @@ void RoundRobin::RoundRobinSubchannelData::ProcessConnectivityChangeLocked( |
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p->TryReresolutionLocked(&grpc_lb_round_robin_trace, GRPC_ERROR_NONE); |
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} |
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// Update state counters.
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subchannel_list()->UpdateStateCountersLocked( |
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prev_connectivity_state_, connectivity_state(), GRPC_ERROR_REF(error)); |
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prev_connectivity_state_ = connectivity_state(); |
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// If we've started watching, update overall state and renew notification.
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if (subchannel_list()->started_watching()) { |
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UpdateConnectivityStateLocked(connectivity_state, error); |
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// Update overall state and renew notification.
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subchannel_list()->UpdateRoundRobinStateFromSubchannelStateCountsLocked(); |
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RenewConnectivityWatchLocked(); |
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} |
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GRPC_ERROR_UNREF(error); |
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} |
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grpc_connectivity_state RoundRobin::CheckConnectivityLocked( |
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grpc_error** error) { |
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Mark D. Roth
7 years ago