wchevreuil commented on a change in pull request #3488: URL: https://github.com/apache/hbase/pull/3488#discussion_r674855549
########## File path: hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeRegionsStrategy.java ########## @@ -0,0 +1,99 @@ +/** + * 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.hadoop.hbase.master.assignment; + +import org.apache.hadoop.fs.FileSystem; +import org.apache.hadoop.fs.Path; +import org.apache.hadoop.hbase.TableName; +import org.apache.hadoop.hbase.client.RegionInfo; +import org.apache.hadoop.hbase.master.MasterFileSystem; +import org.apache.hadoop.hbase.master.RegionState; +import org.apache.hadoop.hbase.master.procedure.MasterProcedureEnv; +import org.apache.hadoop.hbase.regionserver.HRegionFileSystem; +import org.apache.hadoop.hbase.util.CommonFSUtils; +import org.apache.yetus.audience.InterfaceAudience; + +import java.io.IOException; + +/** + * Region merge directory creation strategy to decouple create dir logic from + * <code></code>MergeTableRegionsProcedure</code> and allow for plugable behaviour. + */ +@InterfaceAudience.Private +public abstract class MergeRegionsStrategy { + + /** + * Creates the resulting merging region dir and files in the file system, then updates + * meta table information for the given region. Specific logic on where in the files system to + * create the region structure is delegated to <method>innerMergeRegions</method> and the + * actual <code>HRegionFileSystemWriteStrategy</code> implementation. + * @param env the MasterProcedureEnv wrapping several meta information required. + * @param regionsToMerge array of RegionInfo representing the regions being merged. + * @param mergedRegion the resulting merging region. + * @throws IOException if any error occurs while creating the region dir. + */ + public void createMergedRegion(MasterProcedureEnv env, RegionInfo[] regionsToMerge, + RegionInfo mergedRegion) throws IOException { + final MasterFileSystem mfs = env.getMasterServices().getMasterFileSystem(); + final Path tabledir = CommonFSUtils.getTableDir(mfs.getRootDir(), regionsToMerge[0].getTable()); + final FileSystem fs = mfs.getFileSystem(); + HRegionFileSystem mergeRegionFs = innerMergeRegions(env, fs, regionsToMerge, + tabledir, mergedRegion); + assert mergeRegionFs != null; + mergeRegionFs.commitMergedRegion(mergedRegion); + // Prepare to create merged regions + env.getAssignmentManager().getRegionStates(). + getOrCreateRegionStateNode(mergedRegion).setState(RegionState.State.MERGING_NEW); + } + + /** + * Should define specific logic about where in the file system the region structure should be + * created. + * @param env the MasterProcedureEnv wrapping several meta information required. + * @param fs the FileSystem instance to write the region directory. + * @param regionsToMerge array of RegionInfo representing the regions being merged. + * @param tableDir Path instance for the table dir. + * @param mergedRegion the resulting merging region. + * @return HRegionFileSystem for the resulting merging region. + * @throws IOException if any error occurs while creating the region dir. + */ + abstract protected HRegionFileSystem innerMergeRegions(MasterProcedureEnv env, FileSystem fs, + RegionInfo[] regionsToMerge, Path tableDir, RegionInfo mergedRegion) throws IOException; Review comment: Ack -- 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. To unsubscribe, e-mail: issues-unsubscr...@hbase.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
