Detail
When the Java client API reports the connection statistics, there’s one more connection counted in “opened” than “inPool”, even when “inPool” has reached the
maxConnsPerNode setting. For example:
Cluster Stats: nodes(inUse,inPool,opened,closed): 21 10.0.0.1 3000 sync(0,4,5,0) async(0,0,0,0)
Why is this the case?
Answer
That extra synchronous connection is for tending (please see
FAQ - What is the tend interval ? ), the process by which the client library keeps track of which server nodes and partitions are currently available. This is a necessary part of the client functionality and cannot be disabled.
Applies To Earliest Version
Pre 4.9
Applies To Latest Version
Current Version
