HBASE-22810 Initialize an separate ThreadPoolExecutor for taking/rest…

…oring snapshot (addendum - use the old config key)

hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java

@@ -1281,10 +1281,6 @@ public static enum Modify {
       "hbase.master.executor.logreplayops.threads";
   public static final int MASTER_LOG_REPLAY_OPS_THREADS_DEFAULT = 10;
 
-  public static final String MASTER_SNAPSHOT_OPERATIONS_THREADS =
-      "hbase.master.executor.snapshot.threads";
-  public static final int MASTER_SNAPSHOT_OPERATIONS_THREADS_DEFAULT = 3;
-
   private HConstants() {
     // Can't be instantiated with this ctor.
   }

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

@@ -1173,9 +1173,8 @@ private void startServiceThreads() throws IOException {
         HConstants.MASTER_META_SERVER_OPERATIONS_THREADS_DEFAULT));
     this.service.startExecutorService(ExecutorType.M_LOG_REPLAY_OPS, conf.getInt(
       HConstants.MASTER_LOG_REPLAY_OPS_THREADS, HConstants.MASTER_LOG_REPLAY_OPS_THREADS_DEFAULT));
-    this.service.startExecutorService(ExecutorType.MASTER_SNAPSHOT_OPERATIONS,
-      conf.getInt(HConstants.MASTER_SNAPSHOT_OPERATIONS_THREADS,
-        HConstants.MASTER_SNAPSHOT_OPERATIONS_THREADS_DEFAULT));
+    this.service.startExecutorService(ExecutorType.MASTER_SNAPSHOT_OPERATIONS, conf.getInt(
+      SnapshotManager.SNAPSHOT_POOL_THREADS_KEY, SnapshotManager.SNAPSHOT_POOL_THREADS_DEFAULT));
 
    // We depend on there being only one instance of this executor running
    // at a time.  To do concurrency, would need fencing of enable/disable of

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

@@ -65,12 +65,11 @@ public EnabledTableSnapshotHandler prepare() throws Exception {
   // enforce a snapshot time constraints, but lets us be potentially a bit more robust.
 
   /**
-   * This method kicks off a snapshot procedure.  Other than that it hangs around for various
-   * phases to complete.
+   * This method kicks off a snapshot procedure. Other than that it hangs around for various phases
+   * to complete.
    */
   @Override
-  protected void snapshotRegions(List<Pair<HRegionInfo, ServerName>> regions)
-      throws HBaseSnapshotException, IOException {
+  protected void snapshotRegions(List<Pair<HRegionInfo, ServerName>> regions) throws IOException {
     Set<String> regionServers = new HashSet<String>(regions.size());
     for (Pair<HRegionInfo, ServerName> region : regions) {
       if (region != null && region.getFirst() != null && region.getSecond() != null) {

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

@@ -137,10 +137,10 @@ public class SnapshotManager extends MasterProcedureManager implements Stoppable
   public static final String ONLINE_SNAPSHOT_CONTROLLER_DESCRIPTION = "online-snapshot";
 
   /** Conf key for # of threads used by the SnapshotManager thread pool */
-  private static final String SNAPSHOT_POOL_THREADS_KEY = "hbase.snapshot.master.threads";
+  public static final String SNAPSHOT_POOL_THREADS_KEY = "hbase.snapshot.master.threads";
 
   /** number of current operations running on the master */
-  private static final int SNAPSHOT_POOL_THREADS_DEFAULT = 1;
+  public static final int SNAPSHOT_POOL_THREADS_DEFAULT = 1;
 
   private boolean stopped;
   private MasterServices master;  // Needed by TableEventHandlers

hbase-server/src/test/java/org/apache/hadoop/hbase/snapshot/TestConcurrentFlushSnapshotFromClient.java

@@ -0,0 +1,44 @@
+/**
+ * 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.snapshot;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.master.snapshot.SnapshotManager;
+import org.apache.hadoop.hbase.testclassification.ClientTests;
+import org.apache.hadoop.hbase.testclassification.LargeTests;
+import org.junit.BeforeClass;
+import org.junit.experimental.categories.Category;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Category({ ClientTests.class, LargeTests.class })
+public class TestConcurrentFlushSnapshotFromClient extends TestFlushSnapshotFromClient {
+  private static final Logger LOG = LoggerFactory.getLogger(TestFlushSnapshotFromClient.class);
+
+  @BeforeClass
+  public static void setupCluster() throws Exception {
+    setupConf(UTIL.getConfiguration());
+    UTIL.startMiniCluster(3);
+  }
+
+  protected static void setupConf(Configuration conf) {
+    TestFlushSnapshotFromClient.setupConf(conf);
+    UTIL.getConfiguration().setInt(SnapshotManager.SNAPSHOT_POOL_THREADS_KEY, 3);
+    LOG.info("Config the {} to be 3", SnapshotManager.SNAPSHOT_POOL_THREADS_KEY);
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/snapshot/TestFlushSnapshotFromClient.java

@@ -18,7 +18,6 @@
 package org.apache.hadoop.hbase.snapshot;
 
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.io.IOException;
@@ -27,7 +26,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.CountDownLatch;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -65,7 +63,7 @@
 @Category(LargeTests.class)
 public class TestFlushSnapshotFromClient {
   private static final Log LOG = LogFactory.getLog(TestFlushSnapshotFromClient.class);
-  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
+  protected static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
   private static final int NUM_RS = 2;
   private static final byte[] TEST_FAM = Bytes.toBytes("fam");
   private static final TableName TABLE_NAME = TableName.valueOf("test");
@@ -86,7 +84,7 @@ public static void setupCluster() throws Exception {
     UTIL.startMiniCluster(NUM_RS);
   }
 
-  private static void setupConf(Configuration conf) {
+  protected static void setupConf(Configuration conf) {
     // disable the ui
     conf.setInt("hbase.regionsever.info.port", -1);
     // change the flush size to a small amount, regulating number of store files
@@ -400,111 +398,6 @@ public void testFlushCreateListDestroy() throws Exception {
       snapshotName, rootDir, fs, true);
   }
 
-  /**
-   * Demonstrate that we reject snapshot requests if there is a snapshot already running on the
-   * same table currently running and that concurrent snapshots on different tables can both
-   * succeed concurretly.
-   */
-  @Test(timeout=300000)
-  public void testConcurrentSnapshottingAttempts() throws IOException, InterruptedException {
-    final TableName TABLE2_NAME = TableName.valueOf(TABLE_NAME + "2");
-
-    int ssNum = 20;
-    Admin admin = UTIL.getHBaseAdmin();
-    // make sure we don't fail on listing snapshots
-    SnapshotTestingUtils.assertNoSnapshots(admin);
-    // create second testing table
-    SnapshotTestingUtils.createTable(UTIL, TABLE2_NAME, TEST_FAM);
-    // load the table so we have some data
-    SnapshotTestingUtils.loadData(UTIL, TABLE_NAME, DEFAULT_NUM_ROWS, TEST_FAM);
-    SnapshotTestingUtils.loadData(UTIL, TABLE2_NAME, DEFAULT_NUM_ROWS, TEST_FAM);
-
-    final CountDownLatch toBeSubmitted = new CountDownLatch(ssNum);
-    // We'll have one of these per thread
-    class SSRunnable implements Runnable {
-      SnapshotDescription ss;
-      SSRunnable(SnapshotDescription ss) {
-        this.ss = ss;
-      }
-
-      @Override
-      public void run() {
-        try {
-          Admin admin = UTIL.getHBaseAdmin();
-          LOG.info("Submitting snapshot request: " + ClientSnapshotDescriptionUtils.toString(ss));
-          admin.takeSnapshotAsync(ss);
-        } catch (Exception e) {
-          LOG.info("Exception during snapshot request: " + ClientSnapshotDescriptionUtils.toString(
-              ss)
-              + ".  This is ok, we expect some", e);
-        }
-        LOG.info("Submitted snapshot request: " + ClientSnapshotDescriptionUtils.toString(ss));
-        toBeSubmitted.countDown();
-      }
-    };
-
-    // build descriptions
-    SnapshotDescription[] descs = new SnapshotDescription[ssNum];
-    for (int i = 0; i < ssNum; i++) {
-      SnapshotDescription.Builder builder = SnapshotDescription.newBuilder();
-      builder.setTable(((i % 2) == 0 ? TABLE_NAME : TABLE2_NAME).getNameAsString());
-      builder.setName("ss"+i);
-      builder.setType(SnapshotDescription.Type.FLUSH);
-      descs[i] = builder.build();
-    }
-
-    // kick each off its own thread
-    for (int i=0 ; i < ssNum; i++) {
-      new Thread(new SSRunnable(descs[i])).start();
-    }
-
-    // wait until all have been submitted
-    toBeSubmitted.await();
-
-    // loop until all are done.
-    while (true) {
-      int doneCount = 0;
-      for (SnapshotDescription ss : descs) {
-        try {
-          if (admin.isSnapshotFinished(ss)) {
-            doneCount++;
-          }
-        } catch (Exception e) {
-          LOG.warn("Got an exception when checking for snapshot " + ss.getName(), e);
-          doneCount++;
-        }
-      }
-      if (doneCount == descs.length) {
-        break;
-      }
-      Thread.sleep(100);
-    }
-
-    // dump for debugging
-    UTIL.getHBaseCluster().getMaster().getMasterFileSystem().logFileSystemState(LOG);
-
-    List<SnapshotDescription> taken = admin.listSnapshots();
-    int takenSize = taken.size();
-    LOG.info("Taken " + takenSize + " snapshots:  " + taken);
-    assertTrue("We expect at least 1 request to be rejected because of we concurrently" +
-        " issued many requests", takenSize < ssNum && takenSize > 0);
-
-    // Verify that there's at least one snapshot per table
-    int t1SnapshotsCount = 0;
-    int t2SnapshotsCount = 0;
-    for (SnapshotDescription ss : taken) {
-      if (TableName.valueOf(ss.getTable()).equals(TABLE_NAME)) {
-        t1SnapshotsCount++;
-      } else if (TableName.valueOf(ss.getTable()).equals(TABLE2_NAME)) {
-        t2SnapshotsCount++;
-      }
-    }
-    assertTrue("We expect at least 1 snapshot of table1 ", t1SnapshotsCount > 0);
-    assertTrue("We expect at least 1 snapshot of table2 ", t2SnapshotsCount > 0);
-
-    UTIL.deleteTable(TABLE2_NAME);
-  }
-
   private void waitRegionsAfterMerge(final long numRegionsAfterMerge)
       throws IOException, InterruptedException {
     Admin admin = UTIL.getHBaseAdmin();