com.netflix.servo.publish.CompositeMetricPoller Maven / Gradle / Ivy
/**
* Copyright 2013 Netflix, Inc.
*
* 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.
*/
package com.netflix.servo.publish;
import com.netflix.servo.Metric;
import com.netflix.servo.util.UnmodifiableList;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
/**
* Combines results from a list of metric pollers. This clas
*/
public class CompositeMetricPoller implements MetricPoller {
private static final Logger LOGGER = LoggerFactory.getLogger(CompositeMetricPoller.class);
private static final List EMPTY = UnmodifiableList.of();
private static final String POLLER_KEY = "PollerName";
private final Map pollers;
private final ExecutorService executor;
private final long timeout;
/**
* Creates a new instance for a set of pollers.
*
* @param pollers a set of pollers to collect data from, the map key for a
* poller is used as a name identify a particular poller
* for logging and error messages
* @param executor an executor to use for executing the poll methods
* @param timeout timeout in milliseconds used when getting the value
* from the future
*/
public CompositeMetricPoller(
Map pollers, ExecutorService executor, long timeout) {
this.pollers = Collections.unmodifiableMap(pollers);
this.executor = executor;
this.timeout = timeout;
}
private void increment(Throwable t, String name) {
//TagList tags = SortedTagList.builder().withTag(new BasicTag(POLLER_KEY, name)).build();
//Counters.increment(t.getClass().getSimpleName() + "Count", tags);
}
private List getMetrics(String name, Future> future) {
List metrics = EMPTY;
try {
metrics = future.get(timeout, TimeUnit.MILLISECONDS);
} catch (ExecutionException e) {
increment(e, name);
LOGGER.warn("uncaught exception from poll method for " + name, e);
} catch (TimeoutException e) {
// The cancel is needed to prevent the slow task from using up all threads
future.cancel(true);
increment(e, name);
LOGGER.warn("timeout executing poll method for " + name, e);
} catch (InterruptedException e) {
increment(e, name);
LOGGER.warn("interrupted while doing get for " + name, e);
}
return metrics;
}
/**
* {@inheritDoc}
*/
public final List poll(MetricFilter filter) {
return poll(filter, false);
}
/**
* {@inheritDoc}
*/
public final List poll(MetricFilter filter, boolean reset) {
Map>> futures = new HashMap<>();
for (Map.Entry e : pollers.entrySet()) {
PollCallable task = new PollCallable(e.getValue(), filter, reset);
futures.put(e.getKey(), executor.submit(task));
}
List allMetrics = new ArrayList<>();
for (Map.Entry>> e : futures.entrySet()) {
allMetrics.addAll(getMetrics(e.getKey(), e.getValue()));
}
return allMetrics;
}
}