Increase the free connection

I Have 3 node and i see following in log i wanted allt o have more free conns is it configurable or dynamic based on some property?

2019-10-24T12:58:04.094+08:00 [Info] [Queryport-connpool:] active conns 0, free conns 5

2019-10-24T12:58:07.453+08:00 [Info] [Queryport-connpool:] active conns 0, free conns 122

2019-10-24T12:58:08.095+08:00 [Info] [Queryport-connpool:] active conns 0, free conns 1030


Just to add some context to the logs, these log messages belong to the query service. Query service needs connections to communicate with indexer service to get the query results. So, query service maintains a pool of connections. When there are multiple queries running in parallel, multiple connections will be created. The created connections are not closed aggressively but they are stored in the connection pool for future use. The free connection count in the log message is number of connections stored in the pool for future use. Active connection denote the number of queries running at the time of logging.

With couchbase server 5.5 and above, you will see

  1. Max number of connections in the connection pool can be 5000 (default ). Which means if at any given time, there were 5000 queries running in parallel, pool can hold upto 5000 connections.
  2. When the query rate decreases, unused connections stored in the pool start getting released. Connections are released in the batches of 100 (default) after each 5 second.
  3. When number of connections in the pool reach Low watermark (default 1000), no more connections are released further.

You can change these defaults by changing following setting:

  1. “queryport.client.settings.poolSize”: can be used to change max number of connection to be stored in pool.
  2. “queryport.client.settings.minPoolSizeWM”: can be used to change Low watermark after which no more connections will be released.
  3. “queryport.client.settings.relConnBatchSize”: can be used to change number of connections to be released in 5 second interval.

Thanks Amit.

we are having load and after few hours we see issue in query response . so trying to understand if anything can be addressed on the context .Load test indexer timeout