| package org.apache.helix.agent; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.io.File; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| import org.apache.helix.ExternalCommand; |
| import org.apache.helix.HelixManager; |
| import org.apache.helix.NotificationContext; |
| import org.apache.helix.model.HelixConfigScope; |
| import org.apache.helix.model.Message; |
| import org.apache.helix.model.HelixConfigScope.ConfigScopeProperty; |
| import org.apache.helix.model.builder.HelixConfigScopeBuilder; |
| import org.apache.helix.participant.statemachine.StateModel; |
| import org.apache.helix.participant.statemachine.StateModelInfo; |
| import org.apache.helix.participant.statemachine.Transition; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| @StateModelInfo(initialState = "OFFLINE", states = {}) |
| public class AgentStateModel extends StateModel { |
| private static final Logger _logger = LoggerFactory.getLogger(AgentStateModel.class); |
| private static Pattern pattern = Pattern.compile("(\\{.+?\\})"); |
| |
| private static String buildKey(String fromState, String toState, CommandAttribute attribute) { |
| return fromState + "-" + toState + "." + attribute.getName(); |
| } |
| |
| private static String instantiateByMessage(String string, Message message) { |
| Matcher matcher = pattern.matcher(string); |
| String result = string; |
| while (matcher.find()) { |
| String var = matcher.group(); |
| result = |
| result.replace(var, |
| message.getAttribute(Message.Attributes.valueOf(var.substring(1, var.length() - 1)))); |
| } |
| |
| return result; |
| } |
| |
| @Transition(to = "*", from = "*") |
| public void genericStateTransitionHandler(Message message, NotificationContext context) |
| throws Exception { |
| // first try get command from message |
| String cmd = message.getRecord().getSimpleField(CommandAttribute.COMMAND.getName()); |
| String workingDir = message.getRecord().getSimpleField(CommandAttribute.WORKING_DIR.getName()); |
| String timeout = message.getRecord().getSimpleField(CommandAttribute.TIMEOUT.getName()); |
| String pidFile = message.getRecord().getSimpleField(CommandAttribute.PID_FILE.getName()); |
| |
| HelixManager manager = context.getManager(); |
| String clusterName = manager.getClusterName(); |
| String fromState = message.getFromState(); |
| String toState = message.getToState(); |
| |
| // construct keys for command-config |
| String cmdKey = buildKey(fromState, toState, CommandAttribute.COMMAND); |
| String workingDirKey = buildKey(fromState, toState, CommandAttribute.WORKING_DIR); |
| String timeoutKey = buildKey(fromState, toState, CommandAttribute.TIMEOUT); |
| String pidFileKey = buildKey(fromState, toState, CommandAttribute.PID_FILE); |
| List<String> cmdConfigKeys = Arrays.asList(cmdKey, workingDirKey, timeoutKey, pidFileKey); |
| |
| // read command from resource-scope configures |
| if (cmd == null) { |
| HelixConfigScope resourceScope = |
| new HelixConfigScopeBuilder(ConfigScopeProperty.RESOURCE).forCluster(clusterName) |
| .forResource(message.getResourceName()).build(); |
| Map<String, String> cmdKeyValueMap = |
| manager.getConfigAccessor().get(resourceScope, cmdConfigKeys); |
| if (cmdKeyValueMap != null) { |
| cmd = cmdKeyValueMap.get(cmdKey); |
| workingDir = cmdKeyValueMap.get(workingDirKey); |
| timeout = cmdKeyValueMap.get(timeoutKey); |
| pidFile = cmdKeyValueMap.get(pidFileKey); |
| } |
| } |
| |
| // if resource-scope doesn't contain command, fall back to cluster-scope configures |
| if (cmd == null) { |
| HelixConfigScope clusterScope = |
| new HelixConfigScopeBuilder(ConfigScopeProperty.CLUSTER).forCluster(clusterName).build(); |
| Map<String, String> cmdKeyValueMap = |
| manager.getConfigAccessor().get(clusterScope, cmdConfigKeys); |
| |
| if (cmdKeyValueMap != null) { |
| cmd = cmdKeyValueMap.get(cmdKey); |
| workingDir = cmdKeyValueMap.get(workingDirKey); |
| timeout = cmdKeyValueMap.get(timeoutKey); |
| pidFile = cmdKeyValueMap.get(pidFileKey); |
| } |
| } |
| |
| if (cmd == null) { |
| throw new Exception("Unable to find command for transition from:" + message.getFromState() |
| + " to:" + message.getToState()); |
| } |
| _logger.info("Executing command: " + cmd + ", using workingDir: " + workingDir + ", timeout: " |
| + timeout + ", on " + manager.getInstanceName()); |
| |
| // skip nop command |
| if (cmd.equals(CommandAttribute.NOP.getName())) { |
| return; |
| } |
| |
| // split the cmd to actual cmd and args[] |
| String cmdSplits[] = cmd.trim().split("\\s+"); |
| String cmdValue = cmdSplits[0]; |
| String args[] = Arrays.copyOfRange(cmdSplits, 1, cmdSplits.length); |
| |
| // get the command-execution timeout |
| long timeoutValue = 0; // 0 means wait for ever |
| if (timeout != null) { |
| try { |
| timeoutValue = Long.parseLong(timeout); |
| } catch (NumberFormatException e) { |
| // OK to use 0 |
| } |
| } |
| ExternalCommand externalCmd = |
| ExternalCommand.executeWithTimeout(new File(workingDir), cmdValue, timeoutValue, args); |
| |
| int exitValue = externalCmd.exitValue(); |
| |
| // debug |
| // System.out.println("command: " + cmd + ", exitValue: " + exitValue |
| // + " output:\n" + externalCmd.getStringOutput()); |
| |
| if (_logger.isDebugEnabled()) { |
| _logger.debug("command: " + cmd + ", exitValue: " + exitValue + " output:\n" |
| + externalCmd.getStringOutput()); |
| } |
| |
| // monitor pid if pidFile exists |
| if (pidFile == null) { |
| // no pid to monitor |
| return; |
| } |
| |
| String pidFileValue = instantiateByMessage(pidFile, message); |
| String pid = SystemUtil.getPidFromFile(new File(pidFileValue)); |
| |
| if (pid != null) { |
| new ProcessMonitorThread(pid).start(); |
| } |
| } |
| } |