HBASE-21413 Empty meta log doesn't get split when restart whole cluster

Signed-off-by: stack <stack@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterWalManager.java

@@ -35,6 +35,7 @@ import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.PathFilter;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.regionserver.wal.AbstractFSWAL;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.hadoop.hbase.util.FSUtils;
 import org.apache.hadoop.hbase.wal.AbstractFSWALProvider;
@@ -408,4 +409,43 @@ public class MasterWalManager {
       }
     }
   }
+
+  /**
+   * For meta region open and closed normally on a server, it may leave some meta
+   * WAL in the server's wal dir. Since meta region is no long on this server,
+   * The SCP won't split those meta wals, just leaving them there. So deleting
+   * the wal dir will fail since the dir is not empty. Actually We can safely achive those
+   * meta log and Archiving the meta log and delete the dir.
+   * @param serverName the server to archive meta log
+   */
+  public void archiveMetaLog(final ServerName serverName) {
+    try {
+      Path logDir = new Path(this.rootDir,
+          AbstractFSWALProvider.getWALDirectoryName(serverName.toString()));
+      Path splitDir = logDir.suffix(AbstractFSWALProvider.SPLITTING_EXT);
+      if (fs.exists(splitDir)) {
+        FileStatus[] logfiles = FSUtils.listStatus(fs, splitDir, META_FILTER);
+        if (logfiles != null) {
+          for (FileStatus status : logfiles) {
+            if (!status.isDir()) {
+              Path newPath = AbstractFSWAL.getWALArchivePath(this.oldLogDir,
+                  status.getPath());
+              if (!FSUtils.renameAndSetModifyTime(fs, status.getPath(), newPath)) {
+                LOG.warn("Unable to move  " + status.getPath() + " to " + newPath);
+              } else {
+                LOG.debug("Archived meta log " + status.getPath() + " to " + newPath);
+              }
+            }
+          }
+        }
+        if (!fs.delete(splitDir, false)) {
+          LOG.warn("Unable to delete log dir. Ignoring. " + splitDir);
+        }
+      }
+    } catch (IOException ie) {
+      LOG.warn("Failed archiving meta log for server " + serverName, ie);
+    }
+  }
+
+
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/ServerCrashProcedure.java

@@ -251,6 +251,9 @@ public class ServerCrashProcedure
     // PROBLEM!!! WE BLOCK HERE.
     am.getRegionStates().logSplitting(this.serverName);
     mwm.splitLog(this.serverName);
+    if (!carryingMeta) {
+      mwm.archiveMetaLog(this.serverName);
+    }
     am.getRegionStates().logSplit(this.serverName);
     LOG.debug("Done splitting WALs {}", this);
   }

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestCleanupMetaWAL.java

@@ -0,0 +1,83 @@
+/**
+ * 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.regionserver;
+
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HBaseClassTestRule;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.RegionInfoBuilder;
+import org.apache.hadoop.hbase.master.MasterFileSystem;
+import org.apache.hadoop.hbase.master.procedure.ServerCrashProcedure;
+import org.apache.hadoop.hbase.testclassification.MediumTests;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.apache.hadoop.hbase.wal.AbstractFSWALProvider.SPLITTING_EXT;
+import static org.junit.Assert.fail;
+
+@Category(MediumTests.class)
+public class TestCleanupMetaWAL {
+  private static final Logger LOG = LoggerFactory.getLogger(TestCleanupMetaWAL.class);
+
+  private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
+
+  @ClassRule
+  public static final HBaseClassTestRule CLASS_RULE =
+      HBaseClassTestRule.forClass(TestCleanupMetaWAL.class);
+
+  @BeforeClass
+  public static void before() throws Exception {
+    TEST_UTIL.startMiniCluster(2);
+  }
+
+  @AfterClass
+  public static void after() throws Exception {
+    TEST_UTIL.shutdownMiniZKCluster();
+  }
+
+  @Test
+  public void testCleanupMetaWAL() throws Exception {
+    TEST_UTIL.createTable(TableName.valueOf("test"), "cf");
+    HRegionServer serverWithMeta = TEST_UTIL.getMiniHBaseCluster()
+        .getRegionServer(TEST_UTIL.getMiniHBaseCluster().getServerWithMeta());
+    TEST_UTIL.getAdmin()
+        .move(RegionInfoBuilder.FIRST_META_REGIONINFO.getEncodedNameAsBytes(), null);
+    TEST_UTIL.getMiniHBaseCluster().killRegionServer(serverWithMeta.getServerName());
+    TEST_UTIL.waitFor(10000, () ->
+        TEST_UTIL.getMiniHBaseCluster().getMaster().getProcedures().stream()
+            .filter(p -> p instanceof ServerCrashProcedure && p.isFinished()).count() > 0);
+    MasterFileSystem fs = TEST_UTIL.getMiniHBaseCluster().getMaster().getMasterFileSystem();
+    Path walPath = new Path(fs.getWALRootDir(), HConstants.HREGION_LOGDIR_NAME);
+    for (FileStatus status : FSUtils.listStatus(fs.getFileSystem(), walPath)) {
+      if (status.getPath().toString().contains(SPLITTING_EXT)) {
+        fail("Should not have splitting wal dir here:" + status);
+      }
+    }
+
+
+  }
+}