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本文主要研究一下 flink 的 HistoryServer
HistoryServer
flink-1.7.2/flink-runtime-web/src/main/java/org/apache/flink/runtime/webmonitor/history/HistoryServer.java
public class HistoryServer {
private static final Logger LOG = LoggerFactory.getLogger(HistoryServer.class);
private final Configuration config;
private final String webAddress;
private final int webPort;
private final long webRefreshIntervalMillis;
private final File webDir;
private final HistoryServerArchiveFetcher archiveFetcher;
@Nullable
private final SSLHandlerFactory serverSSLFactory;
private WebFrontendBootstrap netty;
private final Object startupShutdownLock = new Object();
private final AtomicBoolean shutdownRequested = new AtomicBoolean(false);
private final Thread shutdownHook;
public static void main(String[] args) throws Exception {
ParameterTool pt = ParameterTool.fromArgs(args);
String configDir = pt.getRequired(“configDir”);
LOG.info(“Loading configuration from {}”, configDir);
final Configuration flinkConfig = GlobalConfiguration.loadConfiguration(configDir);
try {
FileSystem.initialize(flinkConfig);
} catch (IOException e) {
throw new Exception(“Error while setting the default filesystem scheme from configuration.”, e);
}
// run the history server
SecurityUtils.install(new SecurityConfiguration(flinkConfig));
try {
SecurityUtils.getInstalledContext().runSecured(new Callable<Integer>() {
@Override
public Integer call() throws Exception {
HistoryServer hs = new HistoryServer(flinkConfig);
hs.run();
return 0;
}
});
System.exit(0);
} catch (Throwable t) {
final Throwable strippedThrowable = ExceptionUtils.stripException(t, UndeclaredThrowableException.class);
LOG.error(“Failed to run HistoryServer.”, strippedThrowable);
strippedThrowable.printStackTrace();
System.exit(1);
}
}
public HistoryServer(Configuration config) throws IOException, FlinkException {
this(config, new CountDownLatch(0));
}
public HistoryServer(Configuration config, CountDownLatch numFinishedPolls) throws IOException, FlinkException {
Preconditions.checkNotNull(config);
Preconditions.checkNotNull(numFinishedPolls);
this.config = config;
if (config.getBoolean(HistoryServerOptions.HISTORY_SERVER_WEB_SSL_ENABLED) && SSLUtils.isRestSSLEnabled(config)) {
LOG.info(“Enabling SSL for the history server.”);
try {
this.serverSSLFactory = SSLUtils.createRestServerSSLEngineFactory(config);
} catch (Exception e) {
throw new IOException(“Failed to initialize SSLContext for the history server.”, e);
}
} else {
this.serverSSLFactory = null;
}
webAddress = config.getString(HistoryServerOptions.HISTORY_SERVER_WEB_ADDRESS);
webPort = config.getInteger(HistoryServerOptions.HISTORY_SERVER_WEB_PORT);
webRefreshIntervalMillis = config.getLong(HistoryServerOptions.HISTORY_SERVER_WEB_REFRESH_INTERVAL);
String webDirectory = config.getString(HistoryServerOptions.HISTORY_SERVER_WEB_DIR);
if (webDirectory == null) {
webDirectory = System.getProperty(“java.io.tmpdir”) + File.separator + “flink-web-history-” + UUID.randomUUID();
}
webDir = new File(webDirectory);
String refreshDirectories = config.getString(HistoryServerOptions.HISTORY_SERVER_ARCHIVE_DIRS);
if (refreshDirectories == null) {
throw new FlinkException(HistoryServerOptions.HISTORY_SERVER_ARCHIVE_DIRS + ” was not configured.”);
}
List<RefreshLocation> refreshDirs = new ArrayList<>();
for (String refreshDirectory : refreshDirectories.split(“,”)) {
try {
Path refreshPath = WebMonitorUtils.validateAndNormalizeUri(new Path(refreshDirectory).toUri());
FileSystem refreshFS = refreshPath.getFileSystem();
refreshDirs.add(new RefreshLocation(refreshPath, refreshFS));
} catch (Exception e) {
// there’s most likely something wrong with the path itself, so we ignore it from here on
LOG.warn(“Failed to create Path or FileSystem for directory ‘{}’. Directory will not be monitored.”, refreshDirectory, e);
}
}
if (refreshDirs.isEmpty()) {
throw new FlinkException(“Failed to validate any of the configured directories to monitor.”);
}
long refreshIntervalMillis = config.getLong(HistoryServerOptions.HISTORY_SERVER_ARCHIVE_REFRESH_INTERVAL);
archiveFetcher = new HistoryServerArchiveFetcher(refreshIntervalMillis, refreshDirs, webDir, numFinishedPolls);
this.shutdownHook = ShutdownHookUtil.addShutdownHook(
HistoryServer.this::stop,
HistoryServer.class.getSimpleName(),
LOG);
}
@VisibleForTesting
int getWebPort() {
return netty.getServerPort();
}
public void run() {
try {
start();
new CountDownLatch(1).await();
} catch (Exception e) {
LOG.error(“Failure while running HistoryServer.”, e);
} finally {
stop();
}
}
// ————————————————————————
// Life-cycle
// ————————————————————————
void start() throws IOException, InterruptedException {
synchronized (startupShutdownLock) {
LOG.info(“Starting history server.”);
Files.createDirectories(webDir.toPath());
LOG.info(“Using directory {} as local cache.”, webDir);
Router router = new Router();
router.addGet(“/:*”, new HistoryServerStaticFileServerHandler(webDir));
if (!webDir.exists() && !webDir.mkdirs()) {
throw new IOException(“Failed to create local directory ” + webDir.getAbsoluteFile() + “.”);
}
createDashboardConfigFile();
archiveFetcher.start();
netty = new WebFrontendBootstrap(router, LOG, webDir, serverSSLFactory, webAddress, webPort, config);
}
}
void stop() {
if (shutdownRequested.compareAndSet(false, true)) {
synchronized (startupShutdownLock) {
LOG.info(“Stopping history server.”);
try {
netty.shutdown();
} catch (Throwable t) {
LOG.warn(“Error while shutting down WebFrontendBootstrap.”, t);
}
archiveFetcher.stop();
try {
LOG.info(“Removing web dashboard root cache directory {}”, webDir);
FileUtils.deleteDirectory(webDir);
} catch (Throwable t) {
LOG.warn(“Error while deleting web root directory {}”, webDir, t);
}
LOG.info(“Stopped history server.”);
// Remove shutdown hook to prevent resource leaks
ShutdownHookUtil.removeShutdownHook(shutdownHook, getClass().getSimpleName(), LOG);
}
}
}
// ————————————————————————
// File generation
// ————————————————————————
static FileWriter createOrGetFile(File folder, String name) throws IOException {
File file = new File(folder, name + “.json”);
if (!file.exists()) {
Files.createFile(file.toPath());
}
FileWriter fr = new FileWriter(file);
return fr;
}
private void createDashboardConfigFile() throws IOException {
try (FileWriter fw = createOrGetFile(webDir, “config”)) {
fw.write(createConfigJson(DashboardConfiguration.from(webRefreshIntervalMillis, ZonedDateTime.now())));
fw.flush();
} catch (IOException ioe) {
LOG.error(“Failed to write config file.”);
throw ioe;
}
}
private static String createConfigJson(DashboardConfiguration dashboardConfiguration) throws IOException {
StringWriter writer = new StringWriter();
JsonGenerator gen = JsonFactory.JACKSON_FACTORY.createGenerator(writer);
gen.writeStartObject();
gen.writeNumberField(DashboardConfiguration.FIELD_NAME_REFRESH_INTERVAL, dashboardConfiguration.getRefreshInterval());
gen.writeNumberField(DashboardConfiguration.FIELD_NAME_TIMEZONE_OFFSET, dashboardConfiguration.getTimeZoneOffset());
gen.writeStringField(DashboardConfiguration.FIELD_NAME_TIMEZONE_NAME, dashboardConfiguration.getTimeZoneName());
gen.writeStringField(DashboardConfiguration.FIELD_NAME_FLINK_VERSION, dashboardConfiguration.getFlinkVersion());
gen.writeStringField(DashboardConfiguration.FIELD_NAME_FLINK_REVISION, dashboardConfiguration.getFlinkRevision());
gen.writeEndObject();
gen.close();
return writer.toString();
}
/**
* Container for the {@link Path} and {@link FileSystem} of a refresh directory.
*/
static class RefreshLocation {
private final Path path;
private final FileSystem fs;
private RefreshLocation(Path path, FileSystem fs) {
this.path = path;
this.fs = fs;
}
public Path getPath() {
return path;
}
public FileSystem getFs() {
return fs;
}
}
}
HistoryServer 提供了 finished jobs 的相关查询功能；构造器从配置中读取 historyserver.web.address、historyserver.web.port(默认 8082)、historyserver.web.refresh-interval(默认 10 秒)、historyserver.web.tmpdir、historyserver.archive.fs.dir、historyserver.archive.fs.refresh-interval(默认 10 秒)，然后创建了 HistoryServerArchiveFetcher
其 run 方法主要是调用 start 方法，该方法主要是启动 HistoryServerArchiveFetcher，然后创建 WebFrontendBootstrap
构造器使用 ShutdownHookUtil.addShutdownHook 注册了 ShutdownHook，在 shutdown 时执行 stop 方法，stop 方法主要是调用 WebFrontendBootstrap 的 shutdown 方法以及 HistoryServerArchiveFetcher 的 stop 方法，然后清理 webDir，移除 shutdownHook
HistoryServerArchiveFetcher
flink-1.7.2/flink-runtime-web/src/main/java/org/apache/flink/runtime/webmonitor/history/HistoryServerArchiveFetcher.java
class HistoryServerArchiveFetcher {
private static final Logger LOG = LoggerFactory.getLogger(HistoryServerArchiveFetcher.class);
private static final JsonFactory jacksonFactory = new JsonFactory();
private static final ObjectMapper mapper = new ObjectMapper();
private final ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor(
new ExecutorThreadFactory(“Flink-HistoryServer-ArchiveFetcher”));
private final JobArchiveFetcherTask fetcherTask;
private final long refreshIntervalMillis;
HistoryServerArchiveFetcher(long refreshIntervalMillis, List<HistoryServer.RefreshLocation> refreshDirs, File webDir, CountDownLatch numFinishedPolls) {
this.refreshIntervalMillis = refreshIntervalMillis;
this.fetcherTask = new JobArchiveFetcherTask(refreshDirs, webDir, numFinishedPolls);
if (LOG.isInfoEnabled()) {
for (HistoryServer.RefreshLocation refreshDir : refreshDirs) {
LOG.info(“Monitoring directory {} for archived jobs.”, refreshDir.getPath());
}
}
}
void start() {
executor.scheduleWithFixedDelay(fetcherTask, 0, refreshIntervalMillis, TimeUnit.MILLISECONDS);
}
void stop() {
executor.shutdown();
try {
if (!executor.awaitTermination(1, TimeUnit.SECONDS)) {
executor.shutdownNow();
}
} catch (InterruptedException ignored) {
executor.shutdownNow();
}
}
/**
* {@link TimerTask} that polls the directories configured as {@link HistoryServerOptions#HISTORY_SERVER_ARCHIVE_DIRS} for
* new job archives.
*/
static class JobArchiveFetcherTask extends TimerTask {
private final List<HistoryServer.RefreshLocation> refreshDirs;
private final CountDownLatch numFinishedPolls;
/** Cache of all available jobs identified by their id. */
private final Set<String> cachedArchives;
private final File webDir;
private final File webJobDir;
private final File webOverviewDir;
private static final String JSON_FILE_ENDING = “.json”;
JobArchiveFetcherTask(List<HistoryServer.RefreshLocation> refreshDirs, File webDir, CountDownLatch numFinishedPolls) {
this.refreshDirs = checkNotNull(refreshDirs);
this.numFinishedPolls = numFinishedPolls;
this.cachedArchives = new HashSet<>();
this.webDir = checkNotNull(webDir);
this.webJobDir = new File(webDir, “jobs”);
webJobDir.mkdir();
this.webOverviewDir = new File(webDir, “overviews”);
webOverviewDir.mkdir();
}
@Override
public void run() {
try {
for (HistoryServer.RefreshLocation refreshLocation : refreshDirs) {
Path refreshDir = refreshLocation.getPath();
FileSystem refreshFS = refreshLocation.getFs();
// contents of /:refreshDir
FileStatus[] jobArchives;
try {
jobArchives = refreshFS.listStatus(refreshDir);
} catch (IOException e) {
LOG.error(“Failed to access job archive location for path {}.”, refreshDir, e);
continue;
}
if (jobArchives == null) {
continue;
}
boolean updateOverview = false;
for (FileStatus jobArchive : jobArchives) {
Path jobArchivePath = jobArchive.getPath();
String jobID = jobArchivePath.getName();
try {
JobID.fromHexString(jobID);
} catch (IllegalArgumentException iae) {
LOG.debug(“Archive directory {} contained file with unexpected name {}. Ignoring file.”,
refreshDir, jobID, iae);
continue;
}
if (cachedArchives.add(jobID)) {
try {
for (ArchivedJson archive : FsJobArchivist.getArchivedJsons(jobArchive.getPath())) {
String path = archive.getPath();
String json = archive.getJson();
File target;
if (path.equals(JobsOverviewHeaders.URL)) {
target = new File(webOverviewDir, jobID + JSON_FILE_ENDING);
} else if (path.equals(“/joboverview”)) {// legacy path
json = convertLegacyJobOverview(json);
target = new File(webOverviewDir, jobID + JSON_FILE_ENDING);
} else {
target = new File(webDir, path + JSON_FILE_ENDING);
}
java.nio.file.Path parent = target.getParentFile().toPath();
try {
Files.createDirectories(parent);
} catch (FileAlreadyExistsException ignored) {
// there may be left-over directories from the previous attempt
}
java.nio.file.Path targetPath = target.toPath();
// We overwrite existing files since this may be another attempt at fetching this archive.
// Existing files may be incomplete/corrupt.
Files.deleteIfExists(targetPath);
Files.createFile(target.toPath());
try (FileWriter fw = new FileWriter(target)) {
fw.write(json);
fw.flush();
}
}
updateOverview = true;
} catch (IOException e) {
LOG.error(“Failure while fetching/processing job archive for job {}.”, jobID, e);
// Make sure we attempt to fetch the archive again
cachedArchives.remove(jobID);
// Make sure we do not include this job in the overview
try {
Files.delete(new File(webOverviewDir, jobID + JSON_FILE_ENDING).toPath());
} catch (IOException ioe) {
LOG.debug(“Could not delete file from overview directory.”, ioe);
}
// Clean up job files we may have created
File jobDirectory = new File(webJobDir, jobID);
try {
FileUtils.deleteDirectory(jobDirectory);
} catch (IOException ioe) {
LOG.debug(“Could not clean up job directory.”, ioe);
}
}
}
}
if (updateOverview) {
updateJobOverview(webOverviewDir, webDir);
}
}
} catch (Exception e) {
LOG.error(“Critical failure while fetching/processing job archives.”, e);
}
numFinishedPolls.countDown();
}
}
private static String convertLegacyJobOverview(String legacyOverview) throws IOException {
JsonNode root = mapper.readTree(legacyOverview);
JsonNode finishedJobs = root.get(“finished”);
JsonNode job = finishedJobs.get(0);
JobID jobId = JobID.fromHexString(job.get(“jid”).asText());
String name = job.get(“name”).asText();
JobStatus state = JobStatus.valueOf(job.get(“state”).asText());
long startTime = job.get(“start-time”).asLong();
long endTime = job.get(“end-time”).asLong();
long duration = job.get(“duration”).asLong();
long lastMod = job.get(“last-modification”).asLong();
JsonNode tasks = job.get(“tasks”);
int numTasks = tasks.get(“total”).asInt();
int pending = tasks.get(“pending”).asInt();
int running = tasks.get(“running”).asInt();
int finished = tasks.get(“finished”).asInt();
int canceling = tasks.get(“canceling”).asInt();
int canceled = tasks.get(“canceled”).asInt();
int failed = tasks.get(“failed”).asInt();
int[] tasksPerState = new int[ExecutionState.values().length];
// pending is a mix of CREATED/SCHEDULED/DEPLOYING
// to maintain the correct number of task states we have to pick one of them
tasksPerState[ExecutionState.SCHEDULED.ordinal()] = pending;
tasksPerState[ExecutionState.RUNNING.ordinal()] = running;
tasksPerState[ExecutionState.FINISHED.ordinal()] = finished;
tasksPerState[ExecutionState.CANCELING.ordinal()] = canceling;
tasksPerState[ExecutionState.CANCELED.ordinal()] = canceled;
tasksPerState[ExecutionState.FAILED.ordinal()] = failed;
JobDetails jobDetails = new JobDetails(jobId, name, startTime, endTime, duration, state, lastMod, tasksPerState, numTasks);
MultipleJobsDetails multipleJobsDetails = new MultipleJobsDetails(Collections.singleton(jobDetails));
StringWriter sw = new StringWriter();
mapper.writeValue(sw, multipleJobsDetails);
return sw.toString();
}
/**
* This method replicates the JSON response that would be given by the JobsOverviewHandler when
* listing both running and finished jobs.
*
* <p>Every job archive contains a joboverview.json file containing the same structure. Since jobs are archived on
* their own however the list of finished jobs only contains a single job.
*
* <p>For the display in the HistoryServer WebFrontend we have to combine these overviews.
*/
private static void updateJobOverview(File webOverviewDir, File webDir) {
try (JsonGenerator gen = jacksonFactory.createGenerator(HistoryServer.createOrGetFile(webDir, JobsOverviewHeaders.URL))) {
File[] overviews = new File(webOverviewDir.getPath()).listFiles();
if (overviews != null) {
Collection<JobDetails> allJobs = new ArrayList<>(overviews.length);
for (File overview : overviews) {
MultipleJobsDetails subJobs = mapper.readValue(overview, MultipleJobsDetails.class);
allJobs.addAll(subJobs.getJobs());
}
mapper.writeValue(gen, new MultipleJobsDetails(allJobs));
}
} catch (IOException ioe) {
LOG.error(“Failed to update job overview.”, ioe);
}
}
}
HistoryServerArchiveFetcher 主要是以 historyserver.archive.fs.refresh-interval 的时间间隔从 historyserver.archive.fs.dir 目录拉取 job archives；它内部创建了 JobArchiveFetcherTask 来执行这个任务
JobArchiveFetcherTask 继承了 jdk 的 TimerTask，其 run 方法就是遍历 refreshDirs，然后执行 FileSystem.listStatus，然后使用 FsJobArchivist.getArchivedJsons 获取 ArchivedJson 根据不同 path 写入到指定文件
如果 path 是 /jobs/overview，则写入 webDir/overviews/jobID.json 文件；如果 path 是 /joboverview，则先调用 convertLegacyJobOverview 转换 json，然后再写入 webDir/overviews/jobID.json 文件；其他的 path 则写入 webDir/path.json 文件
WebFrontendBootstrap
flink-1.7.2/flink-runtime-web/src/main/java/org/apache/flink/runtime/webmonitor/utils/WebFrontendBootstrap.java
public class WebFrontendBootstrap {
private final Router router;
private final Logger log;
private final File uploadDir;
private final ServerBootstrap bootstrap;
private final Channel serverChannel;
private final String restAddress;
public WebFrontendBootstrap(
Router router,
Logger log,
File directory,
@Nullable SSLHandlerFactory serverSSLFactory,
String configuredAddress,
int configuredPort,
final Configuration config) throws InterruptedException, UnknownHostException {
this.router = Preconditions.checkNotNull(router);
this.log = Preconditions.checkNotNull(log);
this.uploadDir = directory;
ChannelInitializer<SocketChannel> initializer = new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) {
RouterHandler handler = new RouterHandler(WebFrontendBootstrap.this.router, new HashMap<>());
// SSL should be the first handler in the pipeline
if (serverSSLFactory != null) {
ch.pipeline().addLast(“ssl”, serverSSLFactory.createNettySSLHandler());
}
ch.pipeline()
.addLast(new HttpServerCodec())
.addLast(new ChunkedWriteHandler())
.addLast(new HttpRequestHandler(uploadDir))
.addLast(handler.getName(), handler)
.addLast(new PipelineErrorHandler(WebFrontendBootstrap.this.log));
}
};
NioEventLoopGroup bossGroup = new NioEventLoopGroup(1);
NioEventLoopGroup workerGroup = new NioEventLoopGroup();
this.bootstrap = new ServerBootstrap();
this.bootstrap
.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(initializer);
ChannelFuture ch;
if (configuredAddress == null) {
ch = this.bootstrap.bind(configuredPort);
} else {
ch = this.bootstrap.bind(configuredAddress, configuredPort);
}
this.serverChannel = ch.sync().channel();
InetSocketAddress bindAddress = (InetSocketAddress) serverChannel.localAddress();
InetAddress inetAddress = bindAddress.getAddress();
final String address;
if (inetAddress.isAnyLocalAddress()) {
address = config.getString(JobManagerOptions.ADDRESS, InetAddress.getLocalHost().getHostName());
} else {
address = inetAddress.getHostAddress();
}
int port = bindAddress.getPort();
this.log.info(“Web frontend listening at {}” + ‘:’ + “{}”, address, port);
final String protocol = serverSSLFactory != null ? “https://” : “http://”;
this.restAddress = protocol + address + ‘:’ + port;
}
public ServerBootstrap getBootstrap() {
return bootstrap;
}
public int getServerPort() {
Channel server = this.serverChannel;
if (server != null) {
try {
return ((InetSocketAddress) server.localAddress()).getPort();
}
catch (Exception e) {
log.error(“Cannot access local server port”, e);
}
}
return -1;
}
public String getRestAddress() {
return restAddress;
}
public void shutdown() {
if (this.serverChannel != null) {
this.serverChannel.close().awaitUninterruptibly();
}
if (bootstrap != null) {
if (bootstrap.group() != null) {
bootstrap.group().shutdownGracefully();
}
if (bootstrap.childGroup() != null) {
bootstrap.childGroup().shutdownGracefully();
}
}
}
}
WebFrontendBootstrap 使用 netty 启动了一个 http server，其 pipeline 有 HttpServerCodec、ChunkedWriteHandler、HttpRequestHandler、RouterHandler、PipelineErrorHandler；其中这里的 RouterHandler 的 Router 有个 GET 的 route，其使用的是 HistoryServerStaticFileServerHandler，用于给 HistoryServer 提供静态文件服务
小结
HistoryServer 提供了 finished jobs 的相关查询功能；其主要由 HistoryServerArchiveFetcher 以及 WebFrontendBootstrap 两部分组成；其 run 方法主要是调用 start 方法，该方法主要是启动 HistoryServerArchiveFetcher，然后创建 WebFrontendBootstrap
HistoryServerArchiveFetcher 主要是以 historyserver.archive.fs.refresh-interval 的时间间隔从 historyserver.archive.fs.dir 目录拉取 job archives；它内部创建了 JobArchiveFetcherTask 来执行这个任务；JobArchiveFetcherTask 继承了 jdk 的 TimerTask，其 run 方法就是遍历 refreshDirs，然后执行 FileSystem.listStatus，然后使用 FsJobArchivist.getArchivedJsons 获取 ArchivedJson 根据不同 path 写入到指定文件
WebFrontendBootstrap 使用 netty 启动了一个 http server，其 pipeline 有 HttpServerCodec、ChunkedWriteHandler、HttpRequestHandler、RouterHandler、PipelineErrorHandler；其中这里的 RouterHandler 的 Router 有个 GET 的 route，其使用的是 HistoryServerStaticFileServerHandler，用于给 HistoryServer 提供静态文件服务
doc
HistoryServer
