HBASE-19999 Remove the SYNC_REPLICATION_ENABLED flag

hbase-replication/src/main/java/org/apache/hadoop/hbase/replication/ReplicationUtils.java

@@ -37,8 +37,6 @@ import org.apache.yetus.audience.InterfaceAudience;
 @InterfaceAudience.Private
 public final class ReplicationUtils {
 
-  public static final String SYNC_REPLICATION_ENABLED = "hbase.replication.sync.enabled";
-
   public static final String REPLICATION_ATTR_NAME = "__rep__";
 
   public static final String REMOTE_WAL_DIR_NAME = "remoteWALs";

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -1804,10 +1804,8 @@ public class HRegionServer extends HasThread implements
   private void setupWALAndReplication() throws IOException {
     boolean isMasterNoTableOrSystemTableOnly = this instanceof HMaster &&
       (!LoadBalancer.isTablesOnMaster(conf) || LoadBalancer.isSystemTablesOnlyOnMaster(conf));
-    if (isMasterNoTableOrSystemTableOnly) {
-      conf.setBoolean(ReplicationUtils.SYNC_REPLICATION_ENABLED, false);
-    }
-    WALFactory factory = new WALFactory(conf, serverName.toString());
+    WALFactory factory =
+        new WALFactory(conf, serverName.toString(), !isMasterNoTableOrSystemTableOnly);
     if (!isMasterNoTableOrSystemTableOnly) {
       // TODO Replication make assumptions here based on the default filesystem impl
       Path oldLogDir = new Path(walRootDir, HConstants.HREGION_OLDLOGDIR_NAME);
@@ -1931,11 +1929,8 @@ public class HRegionServer extends HasThread implements
     }
     this.executorService.startExecutorService(ExecutorType.RS_REFRESH_PEER,
       conf.getInt("hbase.regionserver.executor.refresh.peer.threads", 2));
-
-    if (conf.getBoolean(ReplicationUtils.SYNC_REPLICATION_ENABLED, false)) {
     this.executorService.startExecutorService(ExecutorType.RS_REPLAY_SYNC_REPLICATION_WAL,
-        conf.getInt("hbase.regionserver.executor.replay.sync.replication.wal.threads", 2));
-    }
+      conf.getInt("hbase.regionserver.executor.replay.sync.replication.wal.threads", 1));
 
     Threads.setDaemonThreadRunning(this.walRoller.getThread(), getName() + ".logRoller",
     uncaughtExceptionHandler);

hbase-server/src/main/java/org/apache/hadoop/hbase/wal/SyncReplicationWALProvider.java

@@ -29,6 +29,7 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.Lock;
+import java.util.function.BiPredicate;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import org.apache.hadoop.conf.Configuration;
@@ -67,7 +68,8 @@ public class SyncReplicationWALProvider implements WALProvider, PeerActionListen
 
   private final WALProvider provider;
 
-  private SyncReplicationPeerInfoProvider peerInfoProvider;
+  private SyncReplicationPeerInfoProvider peerInfoProvider =
+      new DefaultSyncReplicationPeerInfoProvider();
 
   private WALFactory factory;
 
@@ -235,4 +237,19 @@ public class SyncReplicationWALProvider implements WALProvider, PeerActionListen
       safeClose(peerId2WAL.remove(peerId));
     }
   }
+
+  private static class DefaultSyncReplicationPeerInfoProvider
+      implements SyncReplicationPeerInfoProvider {
+
+    @Override
+    public Optional<Pair<String, String>> getPeerIdAndRemoteWALDir(RegionInfo info) {
+      return Optional.empty();
+    }
+
+    @Override
+    public boolean checkState(RegionInfo info,
+        BiPredicate<SyncReplicationState, SyncReplicationState> checker) {
+      return false;
+    }
+  }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALFactory.java

@@ -27,7 +27,6 @@ import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.regionserver.wal.MetricsWAL;
 import org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader;
-import org.apache.hadoop.hbase.replication.ReplicationUtils;
 import org.apache.hadoop.hbase.util.CancelableProgressable;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.hadoop.hbase.util.LeaseNotRecoveredException;
@@ -151,6 +150,21 @@ public class WALFactory {
    *          to make a directory
    */
   public WALFactory(Configuration conf, String factoryId) throws IOException {
+    // default enableSyncReplicationWALProvider is true, only disable SyncReplicationWALProvider
+    // for HMaster or HRegionServer which take system table only. See HBASE-19999
+    this(conf, factoryId, true);
+  }
+
+  /**
+   * @param conf must not be null, will keep a reference to read params in later reader/writer
+   *          instances.
+   * @param factoryId a unique identifier for this factory. used i.e. by filesystem implementations
+   *          to make a directory
+   * @param enableSyncReplicationWALProvider whether wrap the wal provider to a
+   *          {@link SyncReplicationWALProvider}
+   */
+  public WALFactory(Configuration conf, String factoryId, boolean enableSyncReplicationWALProvider)
+      throws IOException {
     // until we've moved reader/writer construction down into providers, this initialization must
     // happen prior to provider initialization, in case they need to instantiate a reader/writer.
     timeoutMillis = conf.getInt("hbase.hlog.open.timeout", 300000);
@@ -162,7 +176,7 @@ public class WALFactory {
     // end required early initialization
     if (conf.getBoolean("hbase.regionserver.hlog.enabled", true)) {
       WALProvider provider = createProvider(getProviderClass(WAL_PROVIDER, DEFAULT_WAL_PROVIDER));
-      if (conf.getBoolean(ReplicationUtils.SYNC_REPLICATION_ENABLED, false)) {
+      if (enableSyncReplicationWALProvider) {
         provider = new SyncReplicationWALProvider(provider);
       }
       provider.init(this, conf, null);

hbase-server/src/test/java/org/apache/hadoop/hbase/replication/TestSyncReplication.java

@@ -84,7 +84,6 @@ public class TestSyncReplication {
   private static void initTestingUtility(HBaseTestingUtility util, String zkParent) {
     util.setZkCluster(ZK_UTIL.getZkCluster());
     Configuration conf = util.getConfiguration();
-    conf.setBoolean(ReplicationUtils.SYNC_REPLICATION_ENABLED, true);
     conf.set(HConstants.ZOOKEEPER_ZNODE_PARENT, zkParent);
     conf.setInt("replication.source.size.capacity", 102400);
     conf.setLong("replication.source.sleepforretries", 100);

hbase-server/src/test/java/org/apache/hadoop/hbase/replication/master/TestRecoverStandbyProcedure.java

@@ -45,7 +45,6 @@ import org.apache.hadoop.hbase.procedure2.ProcedureExecutor;
 import org.apache.hadoop.hbase.procedure2.ProcedureTestingUtility;
 import org.apache.hadoop.hbase.regionserver.wal.ProtobufLogWriter;
 import org.apache.hadoop.hbase.regionserver.wal.WALUtil;
-import org.apache.hadoop.hbase.replication.ReplicationUtils;
 import org.apache.hadoop.hbase.testclassification.LargeTests;
 import org.apache.hadoop.hbase.testclassification.MasterTests;
 import org.apache.hadoop.hbase.util.Bytes;
@@ -102,7 +101,6 @@ public class TestRecoverStandbyProcedure {
 
   @BeforeClass
   public static void setupCluster() throws Exception {
-    UTIL.getConfiguration().setBoolean(ReplicationUtils.SYNC_REPLICATION_ENABLED, true);
     UTIL.startMiniCluster(RS_NUMBER);
     UTIL.getHBaseCluster().waitForActiveAndReadyMaster();
     conf = UTIL.getConfiguration();

hbase-server/src/test/java/org/apache/hadoop/hbase/wal/TestSyncReplicationWALProvider.java

@@ -36,7 +36,6 @@ import org.apache.hadoop.hbase.regionserver.MultiVersionConcurrencyControl;
 import org.apache.hadoop.hbase.regionserver.wal.DualAsyncFSWAL;
 import org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader;
 import org.apache.hadoop.hbase.regionserver.wal.ProtobufLogTestHelper;
-import org.apache.hadoop.hbase.replication.ReplicationUtils;
 import org.apache.hadoop.hbase.replication.SyncReplicationState;
 import org.apache.hadoop.hbase.replication.regionserver.SyncReplicationPeerInfoProvider;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
@@ -94,7 +93,6 @@ public class TestSyncReplicationWALProvider {
 
   @BeforeClass
   public static void setUpBeforeClass() throws Exception {
-    UTIL.getConfiguration().setBoolean(ReplicationUtils.SYNC_REPLICATION_ENABLED, true);
     UTIL.startMiniDFSCluster(3);
     FACTORY = new WALFactory(UTIL.getConfiguration(), "test");
     ((SyncReplicationWALProvider) FACTORY.getWALProvider()).setPeerInfoProvider(new InfoProvider());