Advice/Best practice for setting listener parameter QUEUESIZE (Oracle 19C) on Linux
We have encountered a situation a couple of times where we've been receiving:
TNS-12518: TNS:listener could not hand off client connection TNS-12540: TNS:internal limit restriction exceeded
After this happens a few times, the listener shuts itself down - I wish it wouldn't but that seems to be how it handles the repeated problem.
After doing a little research on the issue, I think I need to set the QUEUESIZE parameter for my listener. Currently the value is not explicitly set. Our database is running on a Linux server so the default is 128.
A little more digging seems to point to the need to adjust a somaxconn kernel parameter as well. This is not explicitly set in our environment and coincidentally it's default is 128 as well.