Mercurial > hg > thermostat-ng > agent
view plugins/jvm-overview/agent/src/main/java/com/redhat/thermostat/jvm/overview/agent/VmPollingBackend.java @ 2763:845c5af7b42f
Add VM Mapper service
review-thread: http://icedtea.classpath.org/pipermail/thermostat/2017-September/025088.html
reviwed-by: jerboaa
author | Mario Torre <neugens.limasoftware@gmail.com> |
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date | Tue, 26 Sep 2017 15:10:31 +0200 |
parents | 48e1cf54c238 |
children | 9e3d6eedbbee |
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/* * Copyright 2012-2017 Red Hat, Inc. * * This file is part of Thermostat. * * Thermostat is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published * by the Free Software Foundation; either version 2, or (at your * option) any later version. * * Thermostat is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Thermostat; see the file COPYING. If not see * <http://www.gnu.org/licenses/>. * * Linking this code with other modules is making a combined work * based on this code. Thus, the terms and conditions of the GNU * General Public License cover the whole combination. * * As a special exception, the copyright holders of this code give * you permission to link this code with independent modules to * produce an executable, regardless of the license terms of these * independent modules, and to copy and distribute the resulting * executable under terms of your choice, provided that you also * meet, for each linked independent module, the terms and conditions * of the license of that module. An independent module is a module * which is not derived from or based on this code. If you modify * this code, you may extend this exception to your version of the * library, but you are not obligated to do so. If you do not wish * to do so, delete this exception statement from your version. */ package com.redhat.thermostat.jvm.overview.agent; import java.util.HashMap; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.CopyOnWriteArraySet; import java.util.concurrent.ScheduledExecutorService; import java.util.logging.Level; import java.util.logging.Logger; import com.redhat.thermostat.backend.PollingBackend; import com.redhat.thermostat.common.Pair; import com.redhat.thermostat.common.Version; import com.redhat.thermostat.common.utils.LoggingUtils; import com.redhat.thermostat.jvm.overview.agent.internal.model.VmMapperServiceImpl; import com.redhat.thermostat.jvm.overview.agent.model.VmMapperService; /** * Convenience {@link com.redhat.thermostat.backend.Backend} class for implementations that will take some * action for each monitored JVM process on a regular interval. Simply * extend this class, implement any missing methods, and register one or * more {@link VmPollingAction} implementations during instantiation. */ public abstract class VmPollingBackend extends PollingBackend implements VmStatusListener { private final Set<VmPollingAction> actions; private final Map<String, Pair<Integer, VmPollingAction>> badActions; private final Map<Integer, String> pidsToMonitor = new ConcurrentHashMap<>(); private final VmStatusListenerRegistrar registrar; private static final Logger logger = LoggingUtils.getLogger(VmPollingBackend.class); private static final int EXCEPTIONS_THRESHOLD = 10; public VmPollingBackend(String name, String description, String vendor, Version version, ScheduledExecutorService executor, VmStatusListenerRegistrar registrar) { super(name, description, vendor, version, executor); this.registrar = registrar; this.actions = new CopyOnWriteArraySet<>(); this.badActions = new HashMap<>(); } @Override final public void preActivate() { registrar.register(this); } @Override final public void postDeactivate() { registrar.unregister(this); } @Override final public void doScheduledActions() { for (Entry<Integer, String> entry : pidsToMonitor.entrySet()) { int pid = entry.getKey(); String vmId = entry.getValue(); for (VmPollingAction action : actions) { try { action.run(vmId, pid); } catch (Throwable t) { handleActionException(action, vmId); } } } } private synchronized void handleActionException(VmPollingAction action, String vmId) { final String actionName = action.getClass().getName(); final String actionKey = actionName + vmId; Pair<Integer, VmPollingAction> actionPair = badActions.remove(actionKey); if (actionPair == null) { actionPair = new Pair<>(Integer.valueOf(1), action); } int exceptionsPerAction = actionPair.getFirst(); if (exceptionsPerAction < EXCEPTIONS_THRESHOLD) { exceptionsPerAction++; logger.info(VmPollingAction.class.getSimpleName() + " " + actionName + " threw an exception"); badActions.put(actionKey, new Pair<>(exceptionsPerAction, action)); } else { logger.fine("Removing " + actionName + " due to too many repeated exceptions."); unregisterAction(action); } } /** * Register an action to be performed at each polling interval. It is * recommended that implementations register all such actions during * instantiation. */ protected final void registerAction(VmPollingAction action) { actions.add(action); } /** * Unregister an action so that it will no longer be performed at each * polling interval. If no such action has been registered, this * method has no effect. Depending on thread timing issues, the action * may be performed once even after this method has been called. */ protected final void unregisterAction(VmPollingAction action) { actions.remove(action); } @Override public void vmStatusChanged(Status newStatus, String vmId, int pid) { switch (newStatus) { case VM_STARTED: /* fall-through */ case VM_ACTIVE: if (getObserveNewJvm()) { pidsToMonitor.put(pid, vmId); } else { logger.log(Level.FINE, "skipping new vm " + pid); } break; case VM_STOPPED: pidsToMonitor.remove(pid); break; } } }