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

Nicholas_Chamma

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.

Sajan_Sangraula

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

/Sajan

Nicholas_Chamma

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?

Sajan_Sangraula

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

Nicholas_Chamma

Looking at the generated script (which, by the way, is extremely large at 37MB), I see many CREATE PROJECTION statements.

Curtis_1

Take a look at projection_refreshes

Navin_C

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

eli_revach_1

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 .  

amarjeet

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 .