HDDS-1757. Use ExecutorService in OzoneManagerStateMachine. (#1048)

This commit is contained in:
Bharat Viswanadham 2019-07-02 16:02:27 -07:00 committed by Anu Engineer
parent 8b0d1adf31
commit 91cc197227
1 changed files with 41 additions and 2 deletions

View File

@ -19,11 +19,16 @@ package org.apache.hadoop.ozone.om.ratis;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import com.google.protobuf.ServiceException;
import java.io.IOException;
import java.util.Collection;
import java.util.UUID;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import org.apache.hadoop.ozone.container.common.transport.server.ratis
.ContainerStateMachine;
import org.apache.hadoop.ozone.om.OzoneManager;
@ -38,6 +43,7 @@ import org.apache.hadoop.ozone.protocol.proto.OzoneManagerProtocolProtos
import org.apache.hadoop.ozone.protocolPB.OzoneManagerHARequestHandler;
import org.apache.hadoop.ozone.protocolPB.OzoneManagerHARequestHandlerImpl;
import org.apache.hadoop.util.Time;
import org.apache.hadoop.util.concurrent.HadoopExecutors;
import org.apache.ratis.proto.RaftProtos;
import org.apache.ratis.protocol.Message;
import org.apache.ratis.protocol.RaftClientRequest;
@ -70,6 +76,7 @@ public class OzoneManagerStateMachine extends BaseStateMachine {
private RaftGroupId raftGroupId;
private long lastAppliedIndex = 0;
private final OzoneManagerDoubleBuffer ozoneManagerDoubleBuffer;
private final ExecutorService executorService;
public OzoneManagerStateMachine(OzoneManagerRatisServer ratisServer) {
this.omRatisServer = ratisServer;
@ -79,6 +86,9 @@ public class OzoneManagerStateMachine extends BaseStateMachine {
this::updateLastAppliedIndex);
this.handler = new OzoneManagerHARequestHandlerImpl(ozoneManager,
ozoneManagerDoubleBuffer);
ThreadFactory build = new ThreadFactoryBuilder().setDaemon(true)
.setNameFormat("OM StateMachine ApplyTransaction Thread - %d").build();
this.executorService = HadoopExecutors.newSingleThreadExecutor(build);
}
/**
@ -132,8 +142,36 @@ public class OzoneManagerStateMachine extends BaseStateMachine {
OMRequest request = OMRatisHelper.convertByteStringToOMRequest(
trx.getStateMachineLogEntry().getLogData());
long trxLogIndex = trx.getLogEntry().getIndex();
CompletableFuture<Message> future = CompletableFuture
.supplyAsync(() -> runCommand(request, trxLogIndex));
// In the current approach we have one single global thread executor.
// with single thread. Right now this is being done for correctness, as
// applyTransaction will be run on multiple OM's we want to execute the
// transactions in the same order on all OM's, otherwise there is a
// chance that OM replica's can be out of sync.
// TODO: In this way we are making all applyTransactions in
// OM serial order. Revisit this in future to use multiple executors for
// volume/bucket.
// Reason for not immediately implementing executor per volume is, if
// one executor operations are slow, we cannot update the
// lastAppliedIndex in OzoneManager StateMachine, even if other
// executor has completed the transactions with id more.
// We have 300 transactions, And for each volume we have transactions
// of 150. Volume1 transactions 0 - 149 and Volume2 transactions 150 -
// 299.
// Example: Executor1 - Volume1 - 100 (current completed transaction)
// Example: Executor2 - Volume2 - 299 (current completed transaction)
// Now we have applied transactions of 0 - 100 and 149 - 299. We
// cannot update lastAppliedIndex to 299. We need to update it to 100,
// since 101 - 149 are not applied. When OM restarts it will
// applyTransactions from lastAppliedIndex.
// We can update the lastAppliedIndex to 100, and update it to 299,
// only after completing 101 - 149. In initial stage, we are starting
// with single global executor. Will revisit this when needed.
CompletableFuture<Message> future = CompletableFuture.supplyAsync(
() -> runCommand(request, trxLogIndex), executorService);
return future;
} catch (IOException e) {
return completeExceptionally(e);
@ -301,6 +339,7 @@ public class OzoneManagerStateMachine extends BaseStateMachine {
public void stop() {
ozoneManagerDoubleBuffer.stop();
HadoopExecutors.shutdown(executorService, LOG, 5, TimeUnit.SECONDS);
}
}