Removing Unused Hosts from a Vertica Database / Cluster

Products

• CA Infrastructure Management
• CA Performance Management - Usage and Administration
• DX NetOps

Issue/Introduction

This article addresses the steps required to remove unused hosts from a Vertica database cluster. Host removal is often necessary when decommissioning servers, optimizing cluster performance, or reconfiguring the database.

This process involves using Vertica’s Administration Tools and, for larger clusters, requires running specific SQL commands to realign control nodes.

Environment

DX NetOps Performance Management

Cause

Key Scenarios

• Decommissioning unused or outdated hosts.
• Rebalancing cluster resources.
• Ensuring proper database functionality after host removal.

Resolution

Procedure

A. Removing Hosts from the Database

1. Launch Administration Tools

   • Log in as the dbadmin user.
   • Execute:
      

     $ /opt/vertica/bin/admintools

2. Access Advanced Menu

   • From the Main Menu, select Advanced Menu.

3. Navigate to Cluster Management

   • In the Advanced Menu, select Cluster Management and click OK.

4. Initiate Host Removal

   • Within Cluster Management, select Remove Host(s) from Database and click OK.

5. Select the Database

   • Choose the target database from which hosts will be removed and click OK.

6. Choose Hosts to Remove

   • Highlight the hosts intended for removal and click OK.

7. Confirm Removal

   • When prompted, confirm the action by clicking OK.

8. Acknowledge Success

   • Upon successful removal, an acknowledgment message will appear. Click OK to proceed.

Note: Do not stop the database during this process.

Vertica Documentation

B. Removing Hosts from the Cluster

If the removed hosts are not utilized by any other databases within the cluster, proceed to remove them from the cluster configuration.

1. Run update_vertica Command
   • On a remaining active host in the cluster, execute:
      

     # /opt/vertica/sbin/update_vertica --remove-hosts host01,host02,host03

      
     Replace host01, host02, host03 with the actual hostnames or IP addresses of the hosts to be removed.

Note: The update_vertica command performs the following tasks:

• Modifies the spread configuration to reflect the reduced cluster size.
• Adjusts the Administration Tools to operate with the updated cluster configuration.

Important: The database can remain operational during this operation.

 

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References

• Removing Hosts from a Cluster
• Removing Hosts from a Database

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By following these steps, you can effectively remove unused hosts from your Vertica database cluster, maintaining an efficient and well-balanced system.