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  1. HBase
  2. HBASE-22810

Initialize an separate ThreadPoolExecutor for taking/restoring snapshot

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    Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 3.0.0, 1.5.0, 2.3.0, 2.2.1, 2.1.6, 1.3.6, 1.4.11
    • Component/s: None
    • Labels:
      None
    • Hadoop Flags:
      Reviewed
    • Release Note:
      Introduced a new config key for the snapshot taking/restoring operations at master side: hbase.master.executor.snapshot.threads, its default value is 3. means we can have 3 snapshot operations running at the same time.

      Description

      In EventType class, we have the following definition, means taking snapshot & restoring snapshot are use the MASTER_TABLE_OPERATIONS Executor now.

        /**
         * Messages originating from Client to Master.<br>
         * C_M_SNAPSHOT_TABLE<br>
         * Client asking Master to snapshot an offline table.
         */
        C_M_SNAPSHOT_TABLE        (48, ExecutorType.MASTER_TABLE_OPERATIONS),
        /**
         * Messages originating from Client to Master.<br>
         * C_M_RESTORE_SNAPSHOT<br>
         * Client asking Master to restore a snapshot.
         */
        C_M_RESTORE_SNAPSHOT      (49, ExecutorType.MASTER_TABLE_OPERATIONS),
      

      But when I checked the MASTER_TABLE_OPERATIONS thread pool initialization, I see :

        private void startServiceThreads() throws IOException{
         // ...  some other code initializing .... 
      
         // We depend on there being only one instance of this executor running
         // at a time.  To do concurrency, would need fencing of enable/disable of
         // tables.
         // Any time changing this maxThreads to > 1, pls see the comment at
         // AccessController#postCompletedCreateTableAction
         this.executorService.startExecutorService(ExecutorType.MASTER_TABLE_OPERATIONS, 1);
         startProcedureExecutor();
      

      That's to say, for CPs enable or disable table sequencely, we will create a ThreadPoolExecutor with threadPoolSize=1. Then we actually cann't accomplish the snapshoting concurrence even if they are total difference tables, says if there are two table snapshoting request, and the Table A cost 5min for snapshoting, then the Table B need to wait 5min and once Table A finish its snapshot , then Table B will start the snapshot.

      While we've setting the snapshot timeout, so it will be easy to timeout for table B snapshoting . Actually, we can create a separate thead pool for snapshot operations only.

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              • Assignee:
                openinx Zheng Hu
                Reporter:
                openinx Zheng Hu
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                Dates

                • Created:
                  Updated:
                  Resolved: