org.apache.hadoop.hive.common.log.LogRedirector Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.hadoop.hive.common.log;
import org.slf4j.Logger;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.List;
/**
* Class used to redirect output read from a stream to a logger
*/
public class LogRedirector implements Runnable {
private static final long MAX_ERR_LOG_LINES_FOR_RPC = 1000;
public interface LogSourceCallback {
boolean isAlive();
}
private final Logger logger;
private final BufferedReader in;
private final LogSourceCallback callback;
private List errLogs;
private int numErrLogLines = 0;
public LogRedirector(InputStream in, Logger logger, LogSourceCallback callback) {
this.in = new BufferedReader(new InputStreamReader(in));
this.callback = callback;
this.logger = logger;
}
public LogRedirector(InputStream in, Logger logger, List errLogs,
LogSourceCallback callback) {
this.in = new BufferedReader(new InputStreamReader(in));
this.errLogs = errLogs;
this.callback = callback;
this.logger = logger;
}
@Override
public void run() {
try {
String line = null;
while ((line = in.readLine()) != null) {
logger.info(line);
if (errLogs != null) {
if (numErrLogLines++ < MAX_ERR_LOG_LINES_FOR_RPC) {
errLogs.add(line);
}
}
}
} catch (IOException e) {
if (callback.isAlive()) {
logger.warn("I/O error in redirector thread.", e);
} else {
// When stopping the process we are redirecting from,
// the streams might be closed during reading.
// We should not log the related exceptions in a visible level
// as they might mislead the user.
logger.debug("I/O error in redirector thread while stopping the remote driver", e);
}
} catch (Exception e) {
logger.warn("Error in redirector thread.", e);
}
}
/**
* Start the logredirector in a new thread
* @param name name of the new thread
* @param redirector redirector to start
*/
public static void redirect(String name, LogRedirector redirector) {
Thread thread = new Thread(redirector);
thread.setName(name);
thread.setDaemon(true);
thread.start();
}
}