io.delta.flink.sink.internal.writer.DeltaWriterBucketState Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of delta-flink Show documentation
delta-flink
There is a newer version: 3.2.1
/*
 * 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 io.delta.flink.sink.internal.writer;

import org.apache.flink.core.fs.Path;

/**
 * State of a {@link DeltaWriterBucket} that will become part of each application's
 * snapshot created during pre-commit phase of a checkpoint process or manually on demand
 * by the user.
 * see `Fault Tolerance via State Snapshots` section on
 *
 * @see this page
 *
 * 
 * This class is partially inspired by
 * {@link org.apache.flink.connector.file.sink.writer.FileWriterBucketState}
 * but with some modifications like:
 * 

 *   removed snapshotting in-progress file's state because
 *       {@link io.delta.flink.sink.DeltaSink} is supposed to always roll part
 *       files on checkpoint so there is no need to recover any in-progress files' states
 *   extends the state by adding application's unique identifier to guarantee the idempotent
 *       file writes and commits to the {@link io.delta.standalone.DeltaLog}
 * 
 * 
 * Lifecycle of instances of this class is as follows:
 * 

 *     Every instance is being created via {@link DeltaWriter#snapshotState()} method at the
 *     finish phase of each checkpoint interval and serialized as a part of snapshotted app's state.
 *     
It can be also created by the Flink framework itself during failure/snapshot recovery
 *         when it's deserialized from the snapshotted state and provided as input param collection
 *         to {@link io.delta.flink.sink.DeltaSink#createWriter}
 * 
 */
public class DeltaWriterBucketState {

    private final String bucketId;

    private final Path bucketPath;

    private final String appId;

    public DeltaWriterBucketState(
        String bucketId,
        Path bucketPath,
        String appId) {
        this.bucketId = bucketId;
        this.bucketPath = bucketPath;
        this.appId = appId;
    }

    public String getBucketId() {
        return bucketId;
    }

    public Path getBucketPath() {
        return bucketPath;
    }

    @Override
    public String toString() {
        return "BucketState for bucketId=" +
            bucketId +
            " and bucketPath=" +
            bucketPath +
            " and appId=" +
            appId;
    }

    public String getAppId() {
        return appId;
    }
}