/*
* Copyright 2013-2015 the original author or 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.
*/
package org.springframework.cloud.netflix.metrics;
import java.io.IOException;
import java.util.Collection;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import org.springframework.cloud.netflix.metrics.servo.ServoMonitorCache;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import com.netflix.servo.monitor.MonitorConfig;
import com.netflix.servo.tag.SmallTagMap;
import com.netflix.servo.tag.Tags;
/**
* Intercepts RestTemplate requests and records metrics about execution time and results.
*
* @author Jon Schneider
*/
public class MetricsClientHttpRequestInterceptor implements ClientHttpRequestInterceptor {
/**
* The interceptor writes to a Servo MonitorRegistry, which we get away with for now
* because our Spectator implementation is underpinned by a ServoRegistry. When Spring
* Boot (Actuator) provides a more general purpose abstraction for dimensional metrics
* systems, this can be moved there and rewritten against that abstraction.
*/
private final ServoMonitorCache servoMonitorCache;
private final Collection<MetricsTagProvider> tagProviders;
private final String metricName;
public MetricsClientHttpRequestInterceptor(
Collection<MetricsTagProvider> tagProviders,
ServoMonitorCache servoMonitorCache, String metricName) {
this.tagProviders = tagProviders;
this.servoMonitorCache = servoMonitorCache;
this.metricName = metricName;
}
@Override
public ClientHttpResponse intercept(HttpRequest request, byte[] body,
ClientHttpRequestExecution execution) throws IOException {
long startTime = System.nanoTime();
ClientHttpResponse response = null;
try {
response = execution.execute(request, body);
return response;
}
finally {
SmallTagMap.Builder builder = SmallTagMap.builder();
for (MetricsTagProvider tagProvider : tagProviders) {
for (Map.Entry<String, String> tag : tagProvider
.clientHttpRequestTags(request, response).entrySet()) {
builder.add(Tags.newTag(tag.getKey(), tag.getValue()));
}
}
MonitorConfig.Builder monitorConfigBuilder = MonitorConfig
.builder(metricName);
monitorConfigBuilder.withTags(builder);
servoMonitorCache.getTimer(monitorConfigBuilder.build())
.record(System.nanoTime() - startTime, TimeUnit.NANOSECONDS);
}
}
}