Github user zentol commented on a diff in the pull request:
https://github.com/apache/flink/pull/4742#discussion_r142504388
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/job/BlobServerPortHandler.java
---
@@ -0,0 +1,63 @@
+/*
+ * 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.rest.handler.job;
+
+import org.apache.flink.api.common.time.Time;
+import org.apache.flink.runtime.concurrent.FutureUtils;
+import org.apache.flink.runtime.dispatcher.DispatcherGateway;
+import org.apache.flink.runtime.rest.handler.AbstractRestHandler;
+import org.apache.flink.runtime.rest.handler.HandlerRequest;
+import org.apache.flink.runtime.rest.handler.RestHandlerException;
+import org.apache.flink.runtime.rest.messages.BlobServerPortHeaders;
+import org.apache.flink.runtime.rest.messages.BlobServerPortResponseBody;
+import org.apache.flink.runtime.rest.messages.EmptyMessageParameters;
+import org.apache.flink.runtime.rest.messages.EmptyRequestBody;
+import org.apache.flink.runtime.webmonitor.retriever.GatewayRetriever;
+import org.apache.flink.util.ExceptionUtils;
+
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;
+
+import javax.annotation.Nonnull;
+
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * This handler can be used to retrieve the port that the blob server runs
on.
+ */
+public final class BlobServerPortHandler extends
AbstractRestHandler<DispatcherGateway, EmptyRequestBody,
BlobServerPortResponseBody, EmptyMessageParameters> {
+
+ public BlobServerPortHandler(CompletableFuture<String>
localRestAddress, GatewayRetriever<DispatcherGateway> leaderRetriever, Time
timeout) {
+ super(localRestAddress, leaderRetriever, timeout,
BlobServerPortHeaders.getInstance());
+ }
+
+ @Override
+ protected CompletableFuture<BlobServerPortResponseBody>
handleRequest(@Nonnull HandlerRequest<EmptyRequestBody, EmptyMessageParameters>
request, @Nonnull DispatcherGateway gateway) throws RestHandlerException {
+ return gateway
+ .getBlobServerPort(Time.seconds(5))
+ .handleAsync((Integer port, Throwable error) -> {
+ if (error != null) {
+ log.error("Failed to retrieve blob
server port.", ExceptionUtils.stripCompletionException(error));
+ return
FutureUtils.<BlobServerPortResponseBody>completedExceptionally(new
RestHandlerException("Failed to retrieve blob server port.",
HttpResponseStatus.INTERNAL_SERVER_ERROR));
+ } else {
+ return
CompletableFuture.completedFuture(new BlobServerPortResponseBody(port));
+ }
+ })
+ .thenCompose(future -> future);
--- End diff --
Then we would lose the error message. what about
```
return gateway
.getBlobServerPort(timeout)
.thenApply(BlobServerPortResponseBody::new)
.exceptionally(error -> {
throw new CompletionException(new RestHandlerException("Failed
to retrieve blob server port.", HttpResponseStatus.INTERNAL_SERVER_ERROR));
});
```
---
