After adding new vertica nodes , rebalance did not complete and database size varies on each node

Products

• Network Observability

Issue/Introduction

After adding new nodes to a Vertica cluster, the database size is not evenly distributed across all nodes. 

Symptoms:

• Uneven database size across nodes in the cluster.
• Rebalancing tasks may appear incomplete or fail to execute as expected.

Environment

DX NetOps 23.3.x,24.3.x

Cause

The discrepancy in database size across nodes occurred because the rebalancing of data did not complete successfully after the new nodes were added to the Vertica cluster.

Resolution

To resolve the issue of uneven database sizes across Vertica nodes, initiate a rebalance of data across all nodes using the following steps:

1. Stop the Rebalance Process

   Cancel any ongoing rebalance operation to ensure a fresh start:

    

   SELECT CANCEL_REBALANCE_CLUSTER();

    

2. Refresh Projections

   Refresh the projections to ensure data alignment and consistency:

    

   SELECT START_REFRESH();

    

3. Restart Rebalance

   After refreshing projections, initiate the rebalance process:

    

   SELECT START_REBALANCE_CLUSTER();

    

4. Verify and Confirm

Monitor the rebalance operation and confirm that data distribution across all nodes is even.

Following these steps ensures proper rebalancing and optimal data distribution across the Vertica cluster.