prodeezy commented on a change in pull request #695: [WIP] Cherrypick snapshot feature URL: https://github.com/apache/incubator-iceberg/pull/695#discussion_r365117715
########## File path: core/src/main/java/org/apache/iceberg/SnapshotManager.java ########## @@ -0,0 +1,146 @@ +/* + * 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.iceberg; + +import com.google.common.base.Preconditions; +import java.util.HashSet; +import java.util.Set; +import org.apache.iceberg.exceptions.ValidationException; + +public class SnapshotManager extends MergingSnapshotProducer<ManageSnapshots> implements ManageSnapshots { + + private final TableOperations ops; + private SnapshotManagerOperation operation; + private TableMetadata base; + private Long targetSnapshotId = null; + private Set<Long> snapshotsAlreadyCherrypicked; + + enum SnapshotManagerOperation { + CHERRYPICK, + ROLLBACK + } + + SnapshotManager(TableOperations ops) { + super(ops); + this.ops = ops; + this.base = ops.current(); + this.snapshotsAlreadyCherrypicked = new HashSet<>(); + } + + @Override + protected ManageSnapshots self() { + return this; + } + + @Override + protected String operation() { + Snapshot manageSnapshot = base.snapshot(targetSnapshotId); + return manageSnapshot.operation(); + } + + @Override + public ManageSnapshots cherrypick(long snapshotId) { + Preconditions.checkArgument(base.snapshot(snapshotId) != null, + "Cannot cherry pick unknown snapshot id: %s", snapshotId); + + operation = SnapshotManagerOperation.CHERRYPICK; + this.targetSnapshotId = snapshotId; + return this; + } + + @Override + public ManageSnapshots rollback(long snapshotId) { + Preconditions.checkArgument(base.snapshot(snapshotId) != null, + "Cannot roll back to unknown snapshot id: %s", snapshotId); + + operation = SnapshotManagerOperation.ROLLBACK; + this.targetSnapshotId = snapshotId; + return this; + } + + @Override + public ManageSnapshots rollbackToTime(long timestampMillis) { + long snapshotId = 0; + long snapshotTimestamp = 0; + operation = SnapshotManagerOperation.ROLLBACK; + // find the latest snapshot by timestamp older than timestampMillis + for (Snapshot snapshot : base.snapshots()) { + if (snapshot.timestampMillis() < timestampMillis && + snapshot.timestampMillis() > snapshotTimestamp) { + snapshotId = snapshot.snapshotId(); + snapshotTimestamp = snapshot.timestampMillis(); + } + } + + Preconditions.checkArgument(base.snapshot(snapshotId) != null, + "Cannot roll back, no valid snapshot older than: %s", timestampMillis); + + this.targetSnapshotId = snapshotId; + + return this; + } + + @Override + public Snapshot apply() { + // common checks + ValidationException.check(targetSnapshotId != null, + "Cannot run operations on an unknown version: call rollback, rollbackAtTime or cherrypick"); + ValidationException.check(operation != null, + "Need to define operation on snapshot: call rollback, rollbackAtTime or cherrypick"); + + switch (operation) { + case CHERRYPICK: + Snapshot cherryPickSnapshot = base.snapshot(this.targetSnapshotId); + String wapId = stagedWapId(cherryPickSnapshot); + boolean isWapWorkflow = wapId != null && !"".equals(wapId); + if (isWapWorkflow) { + ValidationException.check(!base.isWapIdPublished(wapId), + "Duplicate request to cherry pick wap id that was published already: %s", wapId); + } + // only append operations are currently supported + if (!cherryPickSnapshot.operation().equals(DataOperations.APPEND)) { + throw new UnsupportedOperationException("Can cherry pick only append operations"); + } + // this is to ensure we add files only once for each targetSnapshotId, to protect from + // duplicate additions if commit retries the same cherrypick operation on failure. + if (!snapshotsAlreadyCherrypicked.contains(targetSnapshotId)) { Review comment: on testing this feature we found that when there is high concurrent writing, `ops.commit()` can fail and get retried by the `SnapshotProducer.commit()` .. this requires Cherrypick operation to be idempotent. Since adding files changes state of the base table metadata we need to ensure this is done exactly once. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
