org.apache.hadoop.hive.ql.txn.AcidHouseKeeperService.java Source code

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Here is the source code for org.apache.hadoop.hive.ql.txn.AcidHouseKeeperService.java

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/**
 * 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.hive.ql.txn;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.metastore.HouseKeeperService;
import org.apache.hadoop.hive.metastore.txn.TxnHandler;
import org.apache.hadoop.hive.ql.lockmgr.HiveTxnManager;
import org.apache.hadoop.hive.ql.lockmgr.TxnManagerFactory;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Performs background tasks for Transaction management in Hive.
 * Runs inside Hive Metastore Service.
 */
public class AcidHouseKeeperService implements HouseKeeperService {
    private static final Log LOG = LogFactory.getLog(AcidHouseKeeperService.class);
    private ScheduledExecutorService pool = null;
    private AtomicInteger isAliveCounter = new AtomicInteger(Integer.MIN_VALUE);

    @Override
    public void start(HiveConf hiveConf) throws Exception {
        HiveTxnManager mgr = TxnManagerFactory.getTxnManagerFactory().getTxnManager(hiveConf);
        if (!mgr.supportsAcid()) {
            LOG.info(AcidHouseKeeperService.class.getName() + " not started since " + mgr.getClass().getName()
                    + " does not support Acid.");
            return;//there are no transactions in this case
        }
        pool = Executors.newScheduledThreadPool(1, new ThreadFactory() {
            private final AtomicInteger threadCounter = new AtomicInteger();

            @Override
            public Thread newThread(Runnable r) {
                return new Thread(r, "DeadTxnReaper-" + threadCounter.getAndIncrement());
            }
        });
        TimeUnit tu = TimeUnit.MILLISECONDS;
        pool.scheduleAtFixedRate(new TimedoutTxnReaper(hiveConf, this),
                hiveConf.getTimeVar(HiveConf.ConfVars.HIVE_TIMEDOUT_TXN_REAPER_START, tu),
                hiveConf.getTimeVar(HiveConf.ConfVars.HIVE_TIMEDOUT_TXN_REAPER_INTERVAL, tu),
                TimeUnit.MILLISECONDS);
        LOG.info("Started " + this.getClass().getName() + " with delay/interval = "
                + hiveConf.getTimeVar(HiveConf.ConfVars.HIVE_TIMEDOUT_TXN_REAPER_START, tu) + "/"
                + hiveConf.getTimeVar(HiveConf.ConfVars.HIVE_TIMEDOUT_TXN_REAPER_INTERVAL, tu) + " " + tu);
    }

    @Override
    public void stop() {
        if (pool != null && !pool.isShutdown()) {
            pool.shutdown();
        }
        pool = null;
    }

    @Override
    public String getServiceDescription() {
        return "Abort expired transactions";
    }

    private static final class TimedoutTxnReaper implements Runnable {
        private final TxnHandler txnHandler;
        private final AcidHouseKeeperService owner;

        private TimedoutTxnReaper(HiveConf hiveConf, AcidHouseKeeperService owner) {
            txnHandler = new TxnHandler(hiveConf);
            this.owner = owner;
        }

        @Override
        public void run() {
            try {
                txnHandler.performTimeOuts();
                owner.isAliveCounter.incrementAndGet();
                LOG.info("timeout reaper ran");
            } catch (Throwable t) {
                LOG.fatal("Serious error in " + Thread.currentThread().getName() + ": " + t.getMessage(), t);
            }
        }
    }

    /**
     * This is used for testing only.  Each time the housekeeper runs, counter is incremented by 1.
     * Starts with {@link java.lang.Integer#MIN_VALUE}
     */
    public int getIsAliveCounter() {
        return isAliveCounter.get();
    }
}