hbase-server/src/main/java/org/apache/hadoop/hbase/quotas/ExceedOperationQuota.java

/*
 * 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.quotas;

import org.apache.hadoop.conf.Configuration;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.yetus.audience.InterfaceStability;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos;

/*
 * Internal class used to check and consume quota if exceed throttle quota is enabled. Exceed
 * throttle quota means, user can over consume user/namespace/table quota if region server has
 * additional available quota because other users don't consume at the same time.
 *
 * There are some limits when enable exceed throttle quota:
 * 1. Must set at least one read and one write region server throttle quota;
 * 2. All region server throttle quotas must be in seconds time unit. Because once previous requests
 * exceed their quota and consume region server quota, quota in other time units may be refilled in
 * a long time, this may affect later requests.
 */
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class ExceedOperationQuota extends DefaultOperationQuota {
  private static final Logger LOG = LoggerFactory.getLogger(ExceedOperationQuota.class);
  private QuotaLimiter regionServerLimiter;

  public ExceedOperationQuota(final Configuration conf, int blockSizeBytes,
    QuotaLimiter regionServerLimiter, final QuotaLimiter... limiters) {
    super(conf, blockSizeBytes, limiters);
    this.regionServerLimiter = regionServerLimiter;
  }

  @Override
  public void checkBatchQuota(int numWrites, int numReads) throws RpcThrottlingException {
    Runnable estimateQuota = () -> updateEstimateConsumeBatchQuota(numWrites, numReads);
    CheckQuotaRunnable checkQuota = () -> super.checkBatchQuota(numWrites, numReads);
    checkQuota(estimateQuota, checkQuota, numWrites, numReads, 0);
  }

  @Override
  public void checkScanQuota(ClientProtos.ScanRequest scanRequest, long maxScannerResultSize,
    long maxBlockBytesScanned, long prevBlockBytesScannedDifference) throws RpcThrottlingException {
    Runnable estimateQuota = () -> updateEstimateConsumeScanQuota(scanRequest, maxScannerResultSize,
      maxBlockBytesScanned, prevBlockBytesScannedDifference);
    CheckQuotaRunnable checkQuota = () -> super.checkScanQuota(scanRequest, maxScannerResultSize,
      maxBlockBytesScanned, prevBlockBytesScannedDifference);
    checkQuota(estimateQuota, checkQuota, 0, 0, 1);
  }

  private void checkQuota(Runnable estimateQuota, CheckQuotaRunnable checkQuota, int numWrites,
    int numReads, int numScans) throws RpcThrottlingException {
    if (regionServerLimiter.isBypass()) {
      // If region server limiter is bypass, which means no region server quota is set, check and
      // throttle by all other quotas. In this condition, exceed throttle quota will not work.
      LOG.warn("Exceed throttle quota is enabled but no region server quotas found");
      checkQuota.run();
    } else {
      // 1. Update estimate quota which will be consumed
      estimateQuota.run();
      // 2. Check if region server limiter is enough. If not, throw RpcThrottlingException.
      regionServerLimiter.checkQuota(numWrites, writeConsumed, numReads + numScans, readConsumed,
        writeCapacityUnitConsumed, readCapacityUnitConsumed);
      // 3. Check if other limiters are enough. If not, exceed other limiters because region server
      // limiter is enough.
      boolean exceed = false;
      try {
        checkQuota.run();
      } catch (RpcThrottlingException e) {
        exceed = true;
        if (LOG.isDebugEnabled()) {
          LOG.debug("Read/Write requests num exceeds quota: writes:{} reads:{}, scans:{}, "
            + "try use region server quota", numWrites, numReads, numScans);
        }
      }
      // 4. Region server limiter is enough and grab estimated consume quota.
      readAvailable = Math.max(readAvailable, regionServerLimiter.getReadAvailable());
      regionServerLimiter.grabQuota(numWrites, writeConsumed, numReads + numScans, readConsumed,
        writeCapacityUnitConsumed, writeCapacityUnitConsumed);
      if (exceed) {
        // 5. Other quota limiter is exceeded and has not been grabbed (because throw
        // RpcThrottlingException in Step 3), so grab it.
        for (final QuotaLimiter limiter : limiters) {
          limiter.grabQuota(numWrites, writeConsumed, numReads + numScans, readConsumed,
            writeCapacityUnitConsumed, writeCapacityUnitConsumed);
        }
      }
    }
  }

  @Override
  public void close() {
    super.close();
    if (writeDiff != 0) {
      regionServerLimiter.consumeWrite(writeDiff, writeCapacityUnitDiff);
    }
    if (readDiff != 0) {
      regionServerLimiter.consumeRead(readDiff, readCapacityUnitDiff);
    }
  }

  private interface CheckQuotaRunnable {
    void run() throws RpcThrottlingException;
  }
}