Github user GJL commented on a diff in the pull request:
https://github.com/apache/flink/pull/5223#discussion_r161236268
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/job/savepoints/SavepointHandlers.java
---
@@ -0,0 +1,337 @@
+/*
+ * 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.savepoints;
+
+import org.apache.flink.annotation.VisibleForTesting;
+import org.apache.flink.api.common.JobID;
+import org.apache.flink.api.common.time.Time;
+import org.apache.flink.configuration.CoreOptions;
+import org.apache.flink.runtime.checkpoint.CompletedCheckpoint;
+import org.apache.flink.runtime.concurrent.FutureUtils;
+import org.apache.flink.runtime.rest.NotFoundException;
+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.EmptyRequestBody;
+import org.apache.flink.runtime.rest.messages.JobIDPathParameter;
+import
org.apache.flink.runtime.rest.messages.SavepointTriggerIdPathParameter;
+import org.apache.flink.runtime.rest.messages.job.savepoints.SavepointInfo;
+import
org.apache.flink.runtime.rest.messages.job.savepoints.SavepointResponseBody;
+import
org.apache.flink.runtime.rest.messages.job.savepoints.SavepointStatusHeaders;
+import
org.apache.flink.runtime.rest.messages.job.savepoints.SavepointStatusMessageParameters;
+import
org.apache.flink.runtime.rest.messages.job.savepoints.SavepointTriggerHeaders;
+import
org.apache.flink.runtime.rest.messages.job.savepoints.SavepointTriggerId;
+import
org.apache.flink.runtime.rest.messages.job.savepoints.SavepointTriggerMessageParameters;
+import
org.apache.flink.runtime.rest.messages.job.savepoints.SavepointTriggerRequestBody;
+import
org.apache.flink.runtime.rest.messages.job.savepoints.SavepointTriggerResponseBody;
+import org.apache.flink.runtime.rest.messages.queue.QueueStatus;
+import org.apache.flink.runtime.rpc.RpcUtils;
+import org.apache.flink.runtime.webmonitor.RestfulGateway;
+import org.apache.flink.runtime.webmonitor.retriever.GatewayRetriever;
+import org.apache.flink.types.Either;
+import org.apache.flink.util.SerializedThrowable;
+
+import org.apache.flink.shaded.guava18.com.google.common.cache.Cache;
+import
org.apache.flink.shaded.guava18.com.google.common.cache.CacheBuilder;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+import javax.annotation.concurrent.ThreadSafe;
+
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+
+import static java.util.Objects.requireNonNull;
+
+/**
+ * HTTP handlers for asynchronous triggering of savepoints.
+ *
+ * <p>Drawing savepoints is a potentially long-running operation. To avoid
blocking HTTP
+ * connections, savepoints must be drawn in two steps. First, an HTTP
request is issued to trigger
+ * the savepoint asynchronously. The request will be assigned a {@link
SavepointTriggerId},
+ * which is returned in the response body. Next, the returned id should be
used to poll the status
+ * of the savepoint until it is finished.
+ *
+ * <p>A savepoint is triggered by sending an HTTP {@code POST} request to
+ * {@code /jobs/:jobid/savepoints}. The HTTP request may contain a JSON
body to specify the target
+ * directory of the savepoint, e.g.,
+ * <pre>
+ * { "target-directory": "/tmp" }
+ * </pre>
+ * If the body is omitted, or the field {@code target-property} is {@code
null}, the default
+ * savepoint directory as specified by {@link
CoreOptions#SAVEPOINT_DIRECTORY} will be used.
+ * As written above, the response will contain a request id, e.g.,
+ * <pre>
+ * { "request-id": "7d273f5a62eb4730b9dea8e833733c1e" }
+ * </pre>
+ *
+ * <p>To poll for the status of an ongoing savepoint, an HTTP {@code GET}
request is issued to
+ * {@code /jobs/:jobid/savepoints/:savepointtriggerid}. If the specified
savepoint is still ongoing,
+ * the response will be
+ * <pre>
+ * {
+ * "status": {
+ * "id": "IN_PROGRESS"
+ * }
+ * }
+ * </pre>
+ * If the specified savepoint has completed, the status id will transition
to {@code COMPLETED}, and
+ * the response will additionally contain information about the savepoint,
such as the location:
+ * <pre>
+ * {
+ * "status": {
+ * "id": "COMPLETED"
+ * },
+ * "savepoint": {
+ * "request-id": "7d273f5a62eb4730b9dea8e833733c1e",
+ * "location": "/tmp/savepoint-d9813b-8a68e674325b"
+ * }
+ * }
+ * </pre>
+ */
+public class SavepointHandlers {
+
+ private final CompletedCheckpointCache completedCheckpointCache = new
CompletedCheckpointCache();
+
+ @Nullable
+ private String defaultSavepointDir;
--- End diff --
Could do but additional effort required due to:
```
@VisibleForTesting
void setDefaultSavepointDir(@Nullable final String defaultSavepointDir)
{
this.defaultSavepointDir = defaultSavepointDir;
}
```
---
