// =================================================================================================
// Copyright 2011 Twitter, Inc.
// -------------------------------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this work except in compliance with the License.
// You may obtain a copy of the License in the LICENSE file, or 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.
// =================================================================================================
package com.twitter.common.thrift.callers;
import java.lang.reflect.Method;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import javax.annotation.Nullable;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import org.apache.thrift.async.AsyncMethodCallback;
import com.twitter.common.quantity.Amount;
import com.twitter.common.quantity.Time;
import com.twitter.common.stats.StatsProvider;
import com.twitter.common.stats.StatsProvider.RequestTimer;
import com.twitter.common.thrift.TResourceExhaustedException;
import com.twitter.common.thrift.TTimeoutException;
/**
* A caller that exports statistics about calls made to the wrapped caller.
*
* @author William Farner
*/
public class StatTrackingCaller extends CallerDecorator {
private final StatsProvider statsProvider;
private final String serviceName;
private final LoadingCache<Method, RequestTimer> stats =
CacheBuilder.newBuilder().build(new CacheLoader<Method, RequestTimer>() {
@Override public RequestTimer load(Method method) {
// Thrift does not support overloads - so just the name disambiguates all calls.
return statsProvider.makeRequestTimer(serviceName + "_" + method.getName());
}
});
/**
* Creates a new stat tracking caller, which will export stats to the given {@link StatsProvider}.
*
* @param decoratedCaller The caller to decorate with a deadline.
* @param async Whether the caller is asynchronous.
* @param statsProvider The stat provider to export statistics to.
* @param serviceName The name of the service that methods are being called on.
*/
public StatTrackingCaller(Caller decoratedCaller, boolean async, StatsProvider statsProvider,
String serviceName) {
super(decoratedCaller, async);
this.statsProvider = statsProvider;
this.serviceName = serviceName;
}
@Override
public Object call(Method method, Object[] args, @Nullable AsyncMethodCallback callback,
@Nullable Amount<Long, Time> connectTimeoutOverride) throws Throwable {
final RequestTimer requestStats = stats.get(method);
final long startTime = System.nanoTime();
ResultCapture capture = new ResultCapture() {
@Override public void success() {
requestStats.requestComplete(TimeUnit.NANOSECONDS.toMicros(
System.nanoTime() - startTime));
}
@Override public boolean fail(Throwable t) {
// TODO(John Sirois): the ruby client reconnects for timeouts too - this provides a natural
// backoff mechanism - consider how to plumb something similar.
if (t instanceof TTimeoutException || t instanceof TimeoutException) {
requestStats.incTimeouts();
return true;
}
// TODO(John Sirois): consider ditching reconnects since its nearly redundant with errors as
// it stands.
if (!(t instanceof TResourceExhaustedException)) {
requestStats.incReconnects();
}
// TODO(John Sirois): provide more detailed stats: track counts for distinct exceptions types,
// track retries-per-method, etc...
requestStats.incErrors();
return true;
}
};
return invoke(method, args, callback, capture, connectTimeoutOverride);
}
}