Reuse connections to avoid port starvation
We have an issue with MariaDB and PHP. Queries are working fine, but during bursts we issue too many queries, causing a port starvation. This disconnects all of our users. We have implemented some connection re-use in PHP/PDO and this does bring port usage down, but we are afraid that certain information from previous queries will spill over to the current query. Is there a way to reset the mysql connection without having to disconnect/reconnect?
Answer Answered by Daniel Black in this comment.
There are a bunch of sysctl kernel parameters that will aid in a speedy reuse of ports
net.ipv4.tcp_tw_recycle=1 net.ipv4.tcp_tw_reuse=1 net.ipv4.tcp_fin_timeout=20 (default is 60)
Notes about this will confuse NAT if if that plays a role in your connections.
There is a bit of discussion around this on https://stackoverflow.com/questions/410616/increasing-the-maximum-number-of-tcp-ip-connections-in-linux
Own research recommented.
There's not currently a quick reset to all the mysql connection state on the server.
I recommend creating an issue on https://jira.mariadb.org around port starvation
There are a bunch of sysctl kernel parameters that will aid in a speedy reuse of ports
net.ipv4.tcp_tw_recycle=1 net.ipv4.tcp_tw_reuse=1 net.ipv4.tcp_fin_timeout=20 (default is 60)
Notes about this will confuse NAT if if that plays a role in your connections.
There is a bit of discussion around this on https://stackoverflow.com/questions/410616/increasing-the-maximum-number-of-tcp-ip-connections-in-linux
Own research recommented.