foundationdb/fdbrpc/LoadBalance.actor.cpp

56 lines
2.2 KiB
C++

/*
* LoadBalance.actor.cpp
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2022 Apple Inc. and the FoundationDB project 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.
*/
#include "fdbrpc/LoadBalance.actor.h"
#include "flow/flow.h"
#include "flow/actorcompiler.h" // This must be the last #include.
// Throwing all_alternatives_failed will cause the client to issue a GetKeyLocationRequest to the proxy, so this actor
// attempts to limit the number of these errors thrown by a single client to prevent it from saturating the proxies with
// these requests
ACTOR Future<Void> allAlternativesFailedDelay(Future<Void> okFuture) {
if (now() - g_network->networkInfo.newestAlternativesFailure > FLOW_KNOBS->ALTERNATIVES_FAILURE_RESET_TIME) {
g_network->networkInfo.oldestAlternativesFailure = now();
}
double delay = FLOW_KNOBS->ALTERNATIVES_FAILURE_MIN_DELAY;
if (now() - g_network->networkInfo.lastAlternativesFailureSkipDelay > FLOW_KNOBS->ALTERNATIVES_FAILURE_SKIP_DELAY) {
g_network->networkInfo.lastAlternativesFailureSkipDelay = now();
} else {
double elapsed = now() - g_network->networkInfo.oldestAlternativesFailure;
delay = std::max(delay,
std::min(elapsed * FLOW_KNOBS->ALTERNATIVES_FAILURE_DELAY_RATIO,
FLOW_KNOBS->ALTERNATIVES_FAILURE_MAX_DELAY));
delay = std::max(delay,
std::min(elapsed * FLOW_KNOBS->ALTERNATIVES_FAILURE_SLOW_DELAY_RATIO,
FLOW_KNOBS->ALTERNATIVES_FAILURE_SLOW_MAX_DELAY));
}
g_network->networkInfo.newestAlternativesFailure = now();
choose {
when(wait(okFuture)) {}
when(wait(::delayJittered(delay))) {
throw all_alternatives_failed();
}
}
return Void();
}