/**
    * 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.regionserver.wal;
  
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.metrics.BaseSource;
  
  /**
   * Interface of the source that will export metrics about the region server's WAL.
   */
  public interface MetricsWALSource extends BaseSource {
  
  
    /**
     * The name of the metrics
     */
    String METRICS_NAME = "WAL";
  
    /**
     * The name of the metrics context that metrics will be under.
     */
    String METRICS_CONTEXT = "regionserver";
  
    /**
     * Description
     */
    String METRICS_DESCRIPTION = "Metrics about HBase RegionServer WAL";
  
    /**
     * The name of the metrics context that metrics will be under in jmx
     */
    String METRICS_JMX_CONTEXT = "RegionServer,sub=" + METRICS_NAME;
  
  
    String APPEND_TIME = "appendTime";
    String APPEND_TIME_DESC = "Time an append to the log took.";
    String APPEND_COUNT = "appendCount";
    String APPEND_COUNT_DESC = "Number of appends to the write ahead log.";
    String APPEND_SIZE = "appendSize";
    String APPEND_SIZE_DESC = "Size (in bytes) of the data appended to the WAL.";
    String SLOW_APPEND_COUNT = "slowAppendCount";
    String SLOW_APPEND_COUNT_DESC = "Number of appends that were slow.";
    String SYNC_TIME = "syncTime";
    String SYNC_TIME_DESC = "The time it took to sync the WAL to HDFS.";
    String ROLL_REQUESTED = "rollRequest";
    String ROLL_REQUESTED_DESC = "How many times a roll has been requested total";
    String ERROR_ROLL_REQUESTED = "errorRollRequest";
    String ERROR_ROLL_REQUESTED_DESC =
        "How many times a roll was requested due to I/O or other errors.";
    String LOW_REPLICA_ROLL_REQUESTED = "lowReplicaRollRequest";
    String LOW_REPLICA_ROLL_REQUESTED_DESC =
        "How many times a roll was requested due to too few datanodes in the write pipeline.";
    String SLOW_SYNC_ROLL_REQUESTED = "slowSyncRollRequest";
    String SLOW_SYNC_ROLL_REQUESTED_DESC =
        "How many times a roll was requested due to sync too slow on the write pipeline.";
    String SIZE_ROLL_REQUESTED = "sizeRollRequest";
    String SIZE_ROLL_REQUESTED_DESC =
        "How many times a roll was requested due to file size roll threshold.";
    String WRITTEN_BYTES = "writtenBytes";
    String WRITTEN_BYTES_DESC = "Size (in bytes) of the data written to the WAL.";
    String SUCCESSFUL_LOG_ROLLS = "successfulLogRolls";
    String SUCCESSFUL_LOG_ROLLS_DESC = "Number of successful log rolls requests";
  
    /**
     * Add the append size.
     */
    void incrementAppendSize(TableName tableName, long size);
  
    /**
     * Add the time it took to append.
     */
    void incrementAppendTime(long time);
  
    /**
     * Increment the count of wal appends
     */
    void incrementAppendCount(TableName tableName);
  
    /**
     * Increment the number of appends that were slow
     */
    void incrementSlowAppendCount();
  
   /**
    * Add the time it took to sync the wal.
    */
   void incrementSyncTime(long time);
 
   void incrementLogRollRequested();
 
   void incrementErrorLogRoll();
 
   void incrementLowReplicationLogRoll();
 
   void incrementSlowSyncLogRoll();
 
   void incrementSizeLogRoll();
 
   void incrementWrittenBytes(long val);
 
   /**
    * Increment the number of successful log roll requests.
    */
   void incrementSuccessfulLogRolls();
 
   long getSuccessfulLogRolls();
 }