Github user tillrohrmann commented on a diff in the pull request:
https://github.com/apache/flink/pull/1790#discussion_r56184730
--- Diff:
flink-runtime-web/src/main/java/org/apache/flink/runtime/webmonitor/handlers/TaskManagerLogHandler.java
---
@@ -0,0 +1,345 @@
+/*
+ * 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.flink.runtime.webmonitor.handlers;
+
+/*****************************************************************************
+ * This code is based on the "HttpStaticFileServerHandler" from the
+ * Netty project's HTTP server example.
+ *
+ * See http://netty.io and
+ *
https://github.com/netty/netty/blob/4.0/example/src/main/java/io/netty/example/http/file/HttpStaticFileServerHandler.java
+
*****************************************************************************/
+
+import akka.dispatch.OnComplete;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelFutureListener;
+import io.netty.channel.ChannelHandler;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.DefaultFileRegion;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.handler.codec.http.DefaultFullHttpResponse;
+import io.netty.handler.codec.http.DefaultHttpResponse;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpHeaders;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpResponse;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.handler.codec.http.LastHttpContent;
+import io.netty.handler.codec.http.router.KeepAliveWrite;
+import io.netty.handler.codec.http.router.Routed;
+import io.netty.util.CharsetUtil;
+import io.netty.util.concurrent.GenericFutureListener;
+import org.apache.flink.runtime.blob.BlobKey;
+import org.apache.flink.runtime.instance.ActorGateway;
+import org.apache.flink.runtime.instance.Instance;
+import org.apache.flink.runtime.instance.InstanceID;
+import org.apache.flink.runtime.messages.JobManagerMessages;
+import org.apache.flink.runtime.messages.TaskManagerMessages;
+import org.apache.flink.runtime.webmonitor.JobManagerRetriever;
+import org.apache.flink.runtime.webmonitor.files.MimeTypes;
+import org.apache.flink.runtime.webmonitor.files.StaticFileServerHandler;
+import org.apache.flink.util.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import scala.Option;
+import scala.Tuple2;
+import scala.concurrent.Await;
+import scala.concurrent.ExecutionContextExecutor;
+import scala.concurrent.Future;
+import scala.concurrent.duration.FiniteDuration;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.util.HashMap;
+import java.util.Map;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
+import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
+import static
io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
+import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND;
+import static io.netty.handler.codec.http.HttpResponseStatus.OK;
+import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+
+/**
+ * Request handler that returns the TaskManager log/out files.
+ *
+ * <p>This code is based on the "HttpStaticFileServerHandler" from the
Netty project's HTTP server
+ * example.</p>
+ */
+@ChannelHandler.Sharable
+public class TaskManagerLogHandler extends
SimpleChannelInboundHandler<Routed> {
+
+ /** Default logger, if none is specified */
+ private static final Logger DEFAULT_LOGGER =
LoggerFactory.getLogger(StaticFileServerHandler.class);
+
+ //
------------------------------------------------------------------------
+
+ /** JobManager retriever */
+ private final JobManagerRetriever retriever;
+
+ private final Future<String> localJobManagerAddressFuture;
+
+ private final FiniteDuration timeout;
+
+ /** Keep track of last transmitted log, to clean up old ones */
+ private final HashMap<String, BlobKey> lastSubmittedLog = new
HashMap<>();
+ private final HashMap<String, BlobKey> lastSubmittedStdout = new
HashMap<>();
+
+ /** Keep track of request status, prevents multiple log requests for a
single TM running concurrently */
+ private final HashMap<String, Boolean> lastRequestCompleted = new
HashMap<>();
+
+ /** The log for all error reporting */
+ private final Logger logger;
+
+ /** indicates which log file should be displayed; true indicates .log,
false indicates .out */
+ private final boolean serveLogFile;
+ private final ExecutionContextExecutor executor;
+
+ private String localJobManagerAddress;
+
+ public TaskManagerLogHandler(
+ JobManagerRetriever retriever,
+ ExecutionContextExecutor executor,
+ Future<String> localJobManagerAddressPromise,
+ FiniteDuration timeout,
+ boolean serveLogFile) throws IOException {
+
+ this(retriever, executor, localJobManagerAddressPromise,
timeout, DEFAULT_LOGGER, serveLogFile);
+ }
+
+ public TaskManagerLogHandler(
+ JobManagerRetriever retriever,
+ ExecutionContextExecutor executor,
+ Future<String> localJobManagerAddressFuture,
+ FiniteDuration timeout,
+ Logger logger, boolean serveLogFile) throws IOException {
+
+ this.retriever = checkNotNull(retriever);
+ this.executor = checkNotNull(executor);
+ this.localJobManagerAddressFuture =
checkNotNull(localJobManagerAddressFuture);
+ this.timeout = checkNotNull(timeout);
+ this.logger = checkNotNull(logger);
+ this.serveLogFile = serveLogFile;
+ }
+
+ //
------------------------------------------------------------------------
+ // Responses to requests
+ //
------------------------------------------------------------------------
+
+ @Override
+ public void channelRead0(ChannelHandlerContext ctx, Routed routed)
throws Exception {
+ if (localJobManagerAddressFuture.isCompleted()) {
+ if (localJobManagerAddress == null) {
+ localJobManagerAddress =
Await.result(localJobManagerAddressFuture, timeout);
+ }
+
+ final HttpRequest request = routed.request();
+
+ Option<Tuple2<ActorGateway, Integer>> jobManager =
retriever.getJobManagerGatewayAndWebPort();
+
+ if (jobManager.isDefined()) {
+ // Redirect to leader if necessary
+ String redirectAddress =
HandlerRedirectUtils.getRedirectAddress(
+ localJobManagerAddress,
jobManager.get());
+
+ if (redirectAddress != null) {
+ HttpResponse redirect =
HandlerRedirectUtils.getRedirectResponse(redirectAddress, "");
+ KeepAliveWrite.flush(ctx,
routed.request(), redirect);
+ } else {
+ respondAsLeader(ctx, request,
routed.pathParams(), jobManager.get()._1());
+ }
+ } else {
+ KeepAliveWrite.flush(ctx, routed.request(),
HandlerRedirectUtils.getUnavailableResponse());
+ }
+ } else {
+ KeepAliveWrite.flush(ctx, routed.request(),
HandlerRedirectUtils.getUnavailableResponse());
+ }
+ }
+
+ /**
+ * Response when running with leading JobManager.
+ */
+ private void respondAsLeader(final ChannelHandlerContext ctx, final
HttpRequest request, final Map<String, String> pathParams, final ActorGateway
jobManager) throws Exception {
+ final String taskManagerID =
pathParams.get(TaskManagersHandler.TASK_MANAGER_ID_KEY);
+
+ boolean fetch;
+ synchronized (lastRequestCompleted) {
+ if (!lastRequestCompleted.containsKey(taskManagerID)) {
+ lastRequestCompleted.put(taskManagerID, true);
+ }
+ fetch = lastRequestCompleted.get(taskManagerID);
+ lastRequestCompleted.put(taskManagerID, false);
+ }
+
+ //fetch taskmanager logs if no other process is currently doing
it
+ if (fetch) {
+ //get taskmanager gateway
+ InstanceID instanceID = new
InstanceID(StringUtils.hexStringToByte(taskManagerID));
+ Future<Object> future = jobManager.ask(new
JobManagerMessages.RequestTaskManagerInstance(instanceID), timeout);
+ JobManagerMessages.TaskManagerInstance instance =
(JobManagerMessages.TaskManagerInstance) Await.result(future, timeout);
--- End diff --
No simply use future composition: `map`, `zip`, etc. That way you can
simply define operations for future values. See also
http://doc.akka.io/docs/akka/snapshot/scala/futures.html
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
