Java tutorial
/* * SystemResource.java * * Copyright (c) 2013, Instituto Superior Tcnico. All rights reserved. * * This file is part of bennu-core. * * bennu-core 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 3 of the License, or * (at your option) any later version. * * bennu-core 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 bennu-core. If not, see <http://www.gnu.org/licenses/>. */ package org.fenixedu.bennu.core.api; import java.io.File; import java.io.IOException; import java.lang.Thread.State; import java.lang.management.ClassLoadingMXBean; import java.lang.management.CompilationMXBean; import java.lang.management.GarbageCollectorMXBean; import java.lang.management.ManagementFactory; import java.lang.management.MemoryMXBean; import java.lang.management.MemoryPoolMXBean; import java.lang.management.MemoryUsage; import java.lang.management.OperatingSystemMXBean; import java.lang.management.RuntimeMXBean; import java.lang.management.ThreadMXBean; import java.net.InetAddress; import java.net.UnknownHostException; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Enumeration; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Objects; import java.util.Properties; import java.util.Set; import java.util.concurrent.ConcurrentLinkedQueue; import java.util.concurrent.TimeUnit; import java.util.jar.JarFile; import java.util.stream.Collectors; import javax.management.MBeanServer; import javax.management.ObjectInstance; import javax.servlet.http.HttpServletRequest; import javax.ws.rs.DefaultValue; import javax.ws.rs.GET; import javax.ws.rs.PUT; import javax.ws.rs.Path; import javax.ws.rs.Produces; import javax.ws.rs.QueryParam; import javax.ws.rs.core.Context; import javax.ws.rs.core.MediaType; import org.fenixedu.bennu.core.api.json.KeyValuePropertiesViewer; import org.fenixedu.bennu.core.groups.Group; import org.fenixedu.bennu.core.rest.BennuRestResource; import org.fenixedu.bennu.core.rest.Healthcheck; import org.fenixedu.bennu.core.rest.Healthcheck.Result; import org.fenixedu.commons.configuration.ConfigurationInvocationHandler; import pt.ist.fenixframework.FenixFramework; import pt.ist.fenixframework.core.SharedIdentityMap; import com.google.common.base.Stopwatch; import com.google.gson.JsonArray; import com.google.gson.JsonElement; import com.google.gson.JsonObject; @Path("/bennu-core/system") public class SystemResource extends BennuRestResource { private static String getHostName() { try { return InetAddress.getLocalHost().getHostName(); } catch (UnknownHostException e) { return "<Host name unknown>"; } } @GET @Path("info") @SuppressWarnings("restriction") @Produces({ MediaType.APPLICATION_JSON }) public JsonObject info(@Context HttpServletRequest request, @QueryParam("full") @DefaultValue("true") Boolean full) { accessControl(Group.managers()); JsonObject json = new JsonObject(); if (full) { // fenix-framework projects json.add("projects", getBuilder().view(FenixFramework.getProject().getProjects())); // libraries json.add("libraries", getLibs(request)); // system properties json.add("sys", getBuilder().view(System.getProperties(), Properties.class, KeyValuePropertiesViewer.class)); // environment properties JsonArray env = new JsonArray(); for (Entry<String, String> entry : System.getenv().entrySet()) { JsonObject object = new JsonObject(); object.addProperty("key", entry.getKey()); object.addProperty("value", entry.getValue()); env.add(object); } json.add("env", env); JsonArray headers = new JsonArray(); for (final Enumeration<String> e = request.getHeaderNames(); e.hasMoreElements();) { String header = e.nextElement(); JsonObject object = new JsonObject(); object.addProperty("key", header); object.addProperty("value", request.getHeader(header)); headers.add(object); } json.add("http", headers); json.add("conf", getBuilder().view(ConfigurationInvocationHandler.rawProperties(), Properties.class, KeyValuePropertiesViewer.class)); } JsonObject metrics = new JsonObject(); metrics.addProperty("cacheSize", SharedIdentityMap.getCache().size()); metrics.addProperty("project", FenixFramework.getProject().getName()); metrics.addProperty("version", FenixFramework.getProject().getVersion()); metrics.addProperty("hostname", getHostName()); MemoryMXBean memoryBean = ManagementFactory.getMemoryMXBean(); metrics.addProperty("jvm.memory.total.used", memoryBean.getHeapMemoryUsage().getUsed() + memoryBean.getNonHeapMemoryUsage().getUsed()); metrics.addProperty("jvm.memory.total.max", memoryBean.getHeapMemoryUsage().getMax() + memoryBean.getNonHeapMemoryUsage().getMax()); metrics.addProperty("jvm.memory.heap.used", memoryBean.getHeapMemoryUsage().getUsed()); metrics.addProperty("jvm.memory.heap.max", memoryBean.getHeapMemoryUsage().getMax()); metrics.addProperty("jvm.memory.non-heap.used", memoryBean.getNonHeapMemoryUsage().getUsed()); metrics.addProperty("jvm.memory.non-heap.max", memoryBean.getNonHeapMemoryUsage().getMax()); ThreadMXBean threads = ManagementFactory.getThreadMXBean(); metrics.addProperty("jvm.threads.count", threads.getThreadCount()); ClassLoadingMXBean classLoading = ManagementFactory.getClassLoadingMXBean(); metrics.addProperty("jvm.classloading.loaded.total", classLoading.getTotalLoadedClassCount()); metrics.addProperty("jvm.classloading.loaded", classLoading.getLoadedClassCount()); metrics.addProperty("jvm.classloading.unloaded", classLoading.getUnloadedClassCount()); RuntimeMXBean runtime = ManagementFactory.getRuntimeMXBean(); metrics.addProperty("jvm.runtime.name", runtime.getName()); metrics.addProperty("jvm.runtime.vm.name", runtime.getVmName()); metrics.addProperty("jvm.runtime.vm.vendor", runtime.getVmVendor()); metrics.addProperty("jvm.runtime.vm.version", runtime.getVmVersion()); metrics.addProperty("jvm.runtime.spec.name", runtime.getSpecName()); metrics.addProperty("jvm.runtime.spec.vendor", runtime.getSpecVendor()); metrics.addProperty("jvm.runtime.spec.version", runtime.getSpecVersion()); metrics.addProperty("jvm.runtime.uptime", runtime.getUptime() / 1000); metrics.addProperty("jvm.runtime.start.time", runtime.getStartTime()); metrics.addProperty("now", System.currentTimeMillis()); CompilationMXBean compilation = ManagementFactory.getCompilationMXBean(); metrics.addProperty("jit.name", compilation.getName()); if (compilation.isCompilationTimeMonitoringSupported()) { metrics.addProperty("jit.total.time", compilation.getTotalCompilationTime()); } OperatingSystemMXBean os = ManagementFactory.getOperatingSystemMXBean(); metrics.addProperty("os.name", os.getName()); metrics.addProperty("os.arch", os.getArch()); metrics.addProperty("os.version", os.getVersion()); metrics.addProperty("os.available.cpus", os.getAvailableProcessors()); metrics.addProperty("os.load.average", os.getSystemLoadAverage()); if (os instanceof com.sun.management.OperatingSystemMXBean) { com.sun.management.OperatingSystemMXBean osBean = (com.sun.management.OperatingSystemMXBean) os; metrics.addProperty("os.system.cpu.usage", osBean.getSystemCpuLoad()); metrics.addProperty("os.process.cpu.usage", osBean.getProcessCpuLoad()); metrics.addProperty("os.process.cpu.time", osBean.getProcessCpuTime()); metrics.addProperty("os.free.physical.memory", osBean.getFreePhysicalMemorySize()); metrics.addProperty("os.total.physical.memory", osBean.getTotalPhysicalMemorySize()); metrics.addProperty("os.committed.vm.size", osBean.getCommittedVirtualMemorySize()); } if (os instanceof com.sun.management.UnixOperatingSystemMXBean) { com.sun.management.UnixOperatingSystemMXBean osBean = (com.sun.management.UnixOperatingSystemMXBean) os; metrics.addProperty("os.process.max.fd.count", osBean.getMaxFileDescriptorCount()); metrics.addProperty("os.process.open.fd.count", osBean.getOpenFileDescriptorCount()); } JsonArray gc = new JsonArray(); for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) { JsonObject beanJson = new JsonObject(); beanJson.addProperty("name", bean.getName()); beanJson.addProperty("valid", bean.isValid()); beanJson.addProperty("pools", Arrays.stream(bean.getMemoryPoolNames()).collect(Collectors.joining(", "))); beanJson.addProperty("collectionCount", bean.getCollectionCount()); beanJson.addProperty("collectionTime", bean.getCollectionTime()); gc.add(beanJson); } metrics.add("gc", gc); JsonArray memory = new JsonArray(); for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) { JsonObject beanJson = new JsonObject(); beanJson.addProperty("name", pool.getName()); beanJson.addProperty("type", pool.getType().toString()); beanJson.add("usage", addUsage(pool.getUsage())); beanJson.add("peak", addUsage(pool.getPeakUsage())); beanJson.add("collection", addUsage(pool.getCollectionUsage())); beanJson.addProperty("managers", Arrays.stream(pool.getMemoryManagerNames()).collect(Collectors.joining(", "))); memory.add(beanJson); } metrics.add("memory", memory); json.add("metrics", metrics); return json; } private static final JsonObject addUsage(MemoryUsage usage) { JsonObject json = new JsonObject(); if (usage != null) { json.addProperty("init", usage.getInit()); json.addProperty("used", usage.getUsed()); json.addProperty("committed", usage.getCommitted()); json.addProperty("max", usage.getMax() < 0 ? usage.getUsed() : usage.getMax()); } return json; } private static JsonElement libs; /* * Going through all the libs can be slow, and they never change, * so cache them. */ private static JsonElement getLibs(HttpServletRequest req) { JsonElement json = libs; if (json == null) { try { List<JarFile> libraries = new ArrayList<>(); String libPath = req.getServletContext().getRealPath("/WEB-INF/lib"); // in jetty this is not possible. if (libPath != null) { File[] files = new File(libPath).listFiles(); if (files != null) { for (File file : files) { if (file.getName().endsWith(".jar")) { libraries.add(new JarFile(file)); } } } } json = getBuilder().view(libraries); libs = json; } catch (IOException e) { throw new Error(e); } } return json; } @PUT @Path("/full-gc") public JsonObject fullGC(@Context HttpServletRequest request) { accessControl(Group.managers()); System.gc(); return info(request, false); } @GET @Path("thread-dump") @Produces(MediaType.APPLICATION_JSON) public JsonObject threadDump() { accessControl(Group.managers()); JsonObject json = new JsonObject(); JsonArray array = new JsonArray(); int total = 0; Map<Thread, StackTraceElement[]> threads = Thread.getAllStackTraces(); for (State state : State.values()) { json.addProperty(state.name(), 0); } for (Entry<Thread, StackTraceElement[]> entry : threads.entrySet()) { JsonObject thread = new JsonObject(); String state = entry.getKey().getState().name(); thread.addProperty("name", entry.getKey().toString()); thread.addProperty("state", state); StringBuilder builder = new StringBuilder(); for (StackTraceElement element : entry.getValue()) { builder.append(element); builder.append("\n"); } thread.addProperty("id", entry.getKey().getId()); thread.addProperty("stacktrace", builder.toString()); array.add(thread); json.addProperty(state, json.get(state).getAsInt() + 1); total++; } json.addProperty("totalThreads", total); json.add("threads", array); return json; } @GET @Path("healthcheck") @Produces(MediaType.APPLICATION_JSON) public JsonArray healthChecks() { accessControl(Group.managers()); JsonArray json = new JsonArray(); for (Healthcheck check : healthchecks) { JsonObject obj = new JsonObject(); obj.addProperty("name", check.getName()); Stopwatch stop = Stopwatch.createStarted(); Result result = check.execute(); stop.stop(); obj.add("result", result.toJson()); obj.addProperty("time", stop.elapsed(TimeUnit.MILLISECONDS)); json.add(obj); } return json; } private static final Collection<Healthcheck> healthchecks = new ConcurrentLinkedQueue<>(); public static void registerHealthcheck(Healthcheck healthcheck) { healthchecks.add(Objects.requireNonNull(healthcheck)); } @GET @Path("/jmx") @Produces(MediaType.APPLICATION_JSON) public JsonObject getJmxInfo() { accessControl(Group.managers()); MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); Set<ObjectInstance> objects = mbs.queryMBeans(null, null); JsonObject json = new JsonObject(); for (ObjectInstance instance : objects) { String domain = instance.getObjectName().getDomain(); if (!json.has(domain)) { json.add(domain, new JsonArray()); } json.get(domain).getAsJsonArray().add(getBuilder().view(instance.getObjectName())); } return json; } @GET @Path("/modules") @Produces(MediaType.APPLICATION_JSON) public JsonElement moduleInfo() { return view(FenixFramework.getProject().getProjects(), "modules"); } }