com.netflix.http4.NFHttpMethodRetryHandler.java Source code

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Here is the source code for com.netflix.http4.NFHttpMethodRetryHandler.java

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/*
*
* 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.http4;

/**
 * A simple netflix specific extension class for {@link org.apache.commons.httpclient.DefaultHttpMethodRetryHandler}.
 * 
 * Provides a configurable override for the number of retries. Also waits for a configurable time before retry.
 */
import java.io.IOException;

import org.apache.http.HttpRequest;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.netflix.servo.monitor.DynamicCounter;

public class NFHttpMethodRetryHandler extends DefaultHttpRequestRetryHandler {
    private static final String RETRY_COUNTER = "PLATFORM:NFttpClient:Retries:";
    private Logger logger = LoggerFactory.getLogger(NFHttpMethodRetryHandler.class);
    private int sleepTimeFactorMs;
    private String httpClientName;

    /**
     * Creates a new NFHttpMethodRetryHandler.
     * @param httpClientName - the name of the nfhttpclient
     * @param retryCount the number of times a method will be retried
     * @param requestSentRetryEnabled if true, methods that have successfully sent their request will be retried
     * @param sleepTimeFactorMs number of milliseconds to sleep before the next try. This factor is used along with execution count
     * to determine the sleep time (ie) executionCount * sleepTimeFactorMs
     */
    public NFHttpMethodRetryHandler(String httpClientName, int retryCount, boolean requestSentRetryEnabled,
            int sleepTimeFactorMs) {
        super(retryCount, requestSentRetryEnabled);
        this.httpClientName = httpClientName;
        this.sleepTimeFactorMs = sleepTimeFactorMs;
    }

    @Override
    @edu.umd.cs.findbugs.annotations.SuppressWarnings(value = "ICAST_INTEGER_MULTIPLY_CAST_TO_LONG")
    public boolean retryRequest(final IOException exception, int executionCount, HttpContext context) {
        if (super.retryRequest(exception, executionCount, context)) {
            HttpRequest request = (HttpRequest) context.getAttribute(ExecutionContext.HTTP_REQUEST);
            String methodName = request.getRequestLine().getMethod();
            String path = "UNKNOWN_PATH";
            if (request instanceof HttpUriRequest) {
                HttpUriRequest uriReq = (HttpUriRequest) request;
                path = uriReq.getURI().toString();
            }
            try {
                Thread.sleep(executionCount * this.sleepTimeFactorMs);
            } catch (InterruptedException e) {
                logger.warn("Interrupted while sleep before retrying http method " + methodName + " " + path, e);
            }
            DynamicCounter.increment(RETRY_COUNTER + methodName + ":" + path);
            return true;
        }
        return false;
    }
}