How can I get the status of a data re-balance?

Re-balancing data can take a long time. Is there a way to check on its progress?

I am running the operation from Vertica Admin Tools under Cluster Management.

Comments

  • Hi Nicholas,
    You can check the progress status from the system tables rebalance_projection_status and rebalance_table_status.

    /Sajan
  • In the v_monitor schema? Those two tables seem to be empty. Yet, the re-balance is still running. Is there something else I should check?
  • Take a look at the rebalance script generated. The script should be available as extend_catalog_rebalance.sql in the location you specified when starting the rebalance process.
    If the script only includes drop projection statements, the rebalance tables may not have anything.

    /Sajan
  • Looking at the generated script (which, by the way, is extremely large at 37MB), I see many CREATE PROJECTION statements.
  • Take a look at projection_refreshes
  • Navin_CNavin_C Vertica Customer
    Hi Nicholas,

    If its about Rebalancing, you can try these tables to get the status

    To take a look at already rebalanced projections
    dc_rebalanced_projections.
    To take a look , if projections refresh for a particular projections has started check this table
    dc_rebalance_projection_starts
    And to check the status of rebalance on your cluster
    select sum(separated_bytes)/(sum(to_separate_bytes)+sum(separated_bytes)) * 100 as percentage_separated, sum(transferred_bytes)/(sum(to_transfer_bytes)+sum(transferred_bytes)) * 100 as percentage_transferred
    from REBALANCE_TABLE_STATUS;
    Hope this helps
  • Addtion options is to see it on the OS leval (Linux side) . 
    Rebalance generate extreme I/O activity , which can be view on Level of OS , you shoud see high change of the filesystem utilization during this process ,which you don't see on normal ongoing activity .  
  • Sometime re-balance get stuck and wont show you in system table. Check On tuple mover operation, it will show you what phase it is operating, it is Recreating ros or not. Also I/o and CPU usage will increase .

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