RegionServerQuotaManager

/**
 * 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 java.io.IOException;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.HBaseIOException;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import org.apache.hadoop.hbase.ipc.RpcScheduler;
import org.apache.hadoop.hbase.ipc.RpcServer;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos;
import org.apache.hadoop.hbase.regionserver.Region;
import org.apache.hadoop.hbase.regionserver.RegionServerServices;
import org.apache.hadoop.hbase.security.User;
import org.apache.hadoop.security.UserGroupInformation;

/**
 * Region Server Quota Manager. It is responsible to provide access to the quota information of each
 * user/table. The direct user of this class is the RegionServer that will get and check the
 * user/table quota for each operation (put, get, scan). For system tables and user/table with a
 * quota specified, the quota check will be a noop.
 */
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class RegionServerQuotaManager {
  private static final Log LOG = LogFactory.getLog(RegionServerQuotaManager.class);

  private final RegionServerServices rsServices;

  private QuotaCache quotaCache = null;
  private boolean useRetryableThrottlingException;

  public RegionServerQuotaManager(final RegionServerServices rsServices) {
    this.rsServices = rsServices;
  }

  public void start(final RpcScheduler rpcScheduler) throws IOException {
    if (!QuotaUtil.isQuotaEnabled(rsServices.getConfiguration())) {
      LOG.info("Quota support disabled");
      return;
    }

    LOG.info("Initializing quota support");

    // Initialize quota cache
    quotaCache = new QuotaCache(rsServices);
    quotaCache.start();

    useRetryableThrottlingException = rsServices.getConfiguration()
        .getBoolean(QuotaUtil.QUOTA_RETRYABLE_THROTTING_EXCEPTION_CONF_KEY,
            QuotaUtil.QUOTA_RETRYABLE_THROTTING_EXCEPTION_DEFAULT);
  }

  public void stop() {
    if (isQuotaEnabled()) {
      quotaCache.stop("shutdown");
    }
  }

  public boolean isQuotaEnabled() {
    return quotaCache != null;
  }

  QuotaCache getQuotaCache() {
    return quotaCache;
  }

  /**
   * Returns the quota for an operation.
   * @param ugi the user that is executing the operation
   * @param table the table where the operation will be executed
   * @return the OperationQuota
   */
  public OperationQuota getQuota(final UserGroupInformation ugi, final TableName table) {
    if (isQuotaEnabled() && !table.isSystemTable()) {
      UserQuotaState userQuotaState = quotaCache.getUserQuotaState(ugi);
      QuotaLimiter userLimiter = userQuotaState.getTableLimiter(table);
      boolean useNoop = userLimiter.isBypass();
      if (userQuotaState.hasBypassGlobals()) {
        if (LOG.isTraceEnabled()) {
          LOG.trace("get quota for ugi=" + ugi + " table=" + table + " userLimiter=" + userLimiter);
        }
        if (!useNoop) {
          return new DefaultOperationQuota(this.rsServices.getConfiguration(), userLimiter);
        }
      } else {
        QuotaLimiter nsLimiter = quotaCache.getNamespaceLimiter(table.getNamespaceAsString());
        QuotaLimiter tableLimiter = quotaCache.getTableLimiter(table);
        useNoop &= tableLimiter.isBypass() && nsLimiter.isBypass();
        if (LOG.isTraceEnabled()) {
          LOG.trace("get quota for ugi=" + ugi + " table=" + table + " userLimiter=" + userLimiter
              + " tableLimiter=" + tableLimiter + " nsLimiter=" + nsLimiter);
        }
        if (!useNoop) {
          return new DefaultOperationQuota(this.rsServices.getConfiguration(), userLimiter,
            tableLimiter, nsLimiter);
        }
      }
    }
    return NoopOperationQuota.get();
  }

  /**
   * Check the quota for the current (rpc-context) user. Returns the OperationQuota used to get the
   * available quota and to report the data/usage of the operation.
   * @param region the region where the operation will be performed
   * @param type the operation type
   * @return the OperationQuota
   * @throws ThrottlingException if the operation cannot be executed due to quota exceeded.
   */
  public OperationQuota checkQuota(final Region region, final OperationQuota.OperationType type)
      throws IOException {
    switch (type) {
    case SCAN:
      return checkQuota(region, 0, 0, 1);
    case GET:
      return checkQuota(region, 0, 1, 0);
    case MUTATE:
      return checkQuota(region, 1, 0, 0);
    default:
      throw new RuntimeException("Invalid operation type: " + type);
    }
  }

  /**
   * Check the quota for the current (rpc-context) user. Returns the OperationQuota used to get the
   * available quota and to report the data/usage of the operation.
   * @param region the region where the operation will be performed
   * @param actions the "multi" actions to perform
   * @return the OperationQuota
   * @throws ThrottlingException if the operation cannot be executed due to quota exceeded.
   */
  public OperationQuota checkQuota(final Region region, final List<ClientProtos.Action> actions)
      throws IOException {
    int numWrites = 0;
    int numReads = 0;
    for (final ClientProtos.Action action : actions) {
      if (action.hasMutation()) {
        numWrites++;
      } else if (action.hasGet()) {
        numReads++;
      }
    }
    return checkQuota(region, numWrites, numReads, 0);
  }

  /**
   * Check the quota for the current (rpc-context) user. Returns the OperationQuota used to get the
   * available quota and to report the data/usage of the operation.
   * @param region the region where the operation will be performed
   * @param numWrites number of writes to perform
   * @param numReads number of short-reads to perform
   * @param numScans number of scan to perform
   * @return the OperationQuota
   * @throws ThrottlingException if the operation cannot be executed due to quota exceeded.
   */
  private OperationQuota checkQuota(final Region region, final int numWrites, final int numReads,
      final int numScans) throws IOException {
    User user = RpcServer.getRequestUser();
    UserGroupInformation ugi;
    if (user != null) {
      ugi = user.getUGI();
    } else {
      ugi = User.getCurrent().getUGI();
    }
    TableName table = region.getTableDesc().getTableName();

    OperationQuota quota = getQuota(ugi, table);
    try {
      quota.checkQuota(numWrites, numReads, numScans);
    } catch (HBaseIOException e) {
      LOG.debug("Throttling exception for user=" + ugi.getUserName() + " table=" + table
          + " numWrites=" + numWrites + " numReads=" + numReads + " numScans=" + numScans + ": "
          + e.getMessage());
      // Depending on whether we are supposed to throw a retryable IO exeption or not, choose
      // the correct exception type to (re)throw
      if (useRetryableThrottlingException) {
        throw e;
      } else {
        throw new ThrottlingException(e.getMessage());
      }
    }
    return quota;
  }
}