Drain a load balanced server

  • Last updated on: 2016-01-08
  • Authored by: Kyle Laffoon

Server draining is the redirection of incoming calls and new connections from the specified server to other servers connected to the same load balancer. Draining is used to minimize service interruption when taking a server offline for maintenance. Sessions started before the server is put into draining status continue until completion. When all sessions have ended, the server is considered drained and can then be taken offline. The following steps help to ensure minimal service interruption when removing a cloud server from an active load balancer.

  1. Select the Load Balancers tab.
  2. Click the name of the applicable load balancer to view the connected servers.
  3. Click the gear icon next to server to be drained and select Edit Node Condition.

  4. Select Draining Connections for the server condition and click Save Condition.

  5. Monitor the applicable port of the currently draining node for continued activity (for a Linux server check netstat for new connections).
  6. When activity has ceased, repeat the first 5 steps above (as needed) and select Disabled in the repeated 5th step.

After a server is disabled, it can be removed from the load balancer by clicking on the gear icon next to the server and selecting Remove from Load Balancer and the application can be stopped or the instance deleted, depending on your needs.

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