| /* |
| * 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.hbase.util; |
| |
| import java.io.BufferedReader; |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.IOException; |
| import java.io.InputStreamReader; |
| import java.io.PrintWriter; |
| import java.nio.channels.FileChannel; |
| import java.nio.charset.StandardCharsets; |
| import java.util.Set; |
| import org.apache.hadoop.hbase.logging.Log4jUtils; |
| import org.apache.hadoop.io.IOUtils; |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| /** |
| * Utility functions for reading the log4j logs that are being written by HBase. |
| */ |
| @InterfaceAudience.Private |
| public abstract class LogMonitoring { |
| |
| public static void dumpTailOfLogs(PrintWriter out, long tailKb) throws IOException { |
| Set<File> logs = Log4jUtils.getActiveLogFiles(); |
| for (File f : logs) { |
| out.println("+++++++++++++++++++++++++++++++"); |
| out.println(f.getAbsolutePath()); |
| out.println("+++++++++++++++++++++++++++++++"); |
| try { |
| dumpTailOfLog(f, out, tailKb); |
| } catch (IOException ioe) { |
| out.println("Unable to dump log at " + f); |
| ioe.printStackTrace(out); |
| } |
| out.println("\n\n"); |
| } |
| } |
| |
| private static void dumpTailOfLog(File f, PrintWriter out, long tailKb) throws IOException { |
| FileInputStream fis = new FileInputStream(f); |
| BufferedReader r = null; |
| try { |
| FileChannel channel = fis.getChannel(); |
| channel.position(Math.max(0, channel.size() - tailKb * 1024)); |
| r = new BufferedReader(new InputStreamReader(fis, StandardCharsets.UTF_8)); |
| r.readLine(); // skip the first partial line |
| String line; |
| while ((line = r.readLine()) != null) { |
| out.println(line); |
| } |
| } finally { |
| if (r != null) IOUtils.closeStream(r); |
| IOUtils.closeStream(fis); |
| } |
| } |
| } |