Cloudera Docs

Increase replay buffer size

Increase the default value of the replayBufferSize parameter in Knox to better handle high-load scenarios.

The replayBufferSize parameter in Knox is set to 8 KB by default, which may be insufficient under high-load scenarios. This can result in the error message Existing stream already past replay buffer capacity. Increase the value to 512 KB to mitigate the issue.

  1. In Cloudera Manager, select the Knox service.
  2. Go to Configuration.
  3. Find the Knox Simplified Topology Management - cdp-proxy property.
  4. Add the following line: $SERVICE_NAME:replayBufferSize=512
  5. Save your changes.
  6. Refresh the Knox instances’ configuration: the Refresh needed stale configuration indicator appears; click it and wait until the refresh process completes.
  7. Validate that replayBufferSize=512 in cdp-proxy is added by navigating to the following URL: https://$KNOX_GATEWAY_HOST:$PORT/$GATEWAY_PATH/admin/api/v1/topologies/cdp-proxy.
The replayBufferSize parameter is increased to 512 KB, ensuring better handling of high-load scenarios.