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

   1 /**
   2  * Licensed to the Apache Software Foundation (ASF) under one
   3  * or more contributor license agreements.  See the NOTICE file
   4  * distributed with this work for additional information
   5  * regarding copyright ownership.  The ASF licenses this file
   6  * to you under the Apache License, Version 2.0 (the
   7  * "License"); you may not use this file except in compliance
   8  * with the License.  You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  */
  18
  19 package org.apache.hadoop.hbase.quotas;
  20
  21 import org.apache.yetus.audience.InterfaceAudience;
  22 import org.apache.yetus.audience.InterfaceStability;
  23
  24 /**
  25  * Internal interface used to interact with the user/table quota.
  26  */
  27 @InterfaceAudience.Private
  28 @InterfaceStability.Evolving
  29 public interface QuotaLimiter {
  30   /**
  31    * Checks if it is possible to execute the specified operation.
  32    *
  33    * @param writeReqs the write requests that will be checked against the available quota
  34    * @param estimateWriteSize the write size that will be checked against the available quota
  35    * @param readReqs the read requests that will be checked against the available quota
  36    * @param estimateReadSize the read size that will be checked against the available quota
  37    * @param estimateWriteCapacityUnit the write capacity unit that will be checked against the
  38    *          available quota
  39    * @param estimateReadCapacityUnit the read capacity unit that will be checked against the
  40    *          available quota
  41    * @throws RpcThrottlingException thrown if not enough available resources to perform operation.
  42    */
  43   void checkQuota(long writeReqs, long estimateWriteSize, long readReqs, long estimateReadSize,
  44       long estimateWriteCapacityUnit, long estimateReadCapacityUnit) throws RpcThrottlingException;
  45
  46   /**
  47    * Removes the specified write and read amount from the quota.
  48    * At this point the write and read amount will be an estimate,
  49    * that will be later adjusted with a consumeWrite()/consumeRead() call.
  50    *
  51    * @param writeReqs the write requests that will be removed from the current quota
  52    * @param writeSize the write size that will be removed from the current quota
  53    * @param readReqs the read requests that will be removed from the current quota
  54    * @param readSize the read size that will be removed from the current quota
  55    * @param writeCapacityUnit the write capacity unit that will be removed from the current quota
  56    * @param readCapacityUnit the read capacity unit num that will be removed from the current quota
  57    */
  58   void grabQuota(long writeReqs, long writeSize, long readReqs, long readSize,
  59       long writeCapacityUnit, long readCapacityUnit);
  60
  61   /**
  62    * Removes or add back some write amount to the quota.
  63    * (called at the end of an operation in case the estimate quota was off)
  64    */
  65   void consumeWrite(long size, long capacityUnit);
  66
  67   /**
  68    * Removes or add back some read amount to the quota.
  69    * (called at the end of an operation in case the estimate quota was off)
  70    */
  71   void consumeRead(long size, long capacityUnit);
  72
  73   /** @return true if the limiter is a noop */
  74   boolean isBypass();
  75
  76     /** @return the number of bytes available to read to avoid exceeding the quota */
  77   long getReadAvailable();
  78
  79   /** @return the number of bytes available to write to avoid exceeding the quota */
  80   long getWriteAvailable();
  81 }