Maxscale: Client stops connecting after a while.

MaxScale 2.4.3

2 backend servers, one master, one slave.

Our transaction manager uses maxscale to connect to the master for writes and the slave for reads through readwritesplit.

After a while the transaction server stops connecting with a "|Error| [SQL] Error: can't connect to db"

The number of sessions arn't high.

When we connect the transaction server directly to the master server there is no problem.

Current config below :

[maxscale] threads=auto

[db1] type=server address=db1 port=3306 protocol=MariaDBBackend

[db2] type=server address=db2 port=3306 protocol=MariaDBBackend

[MariaDB-Monitor] type=monitor module=mariadbmon servers=db1,db2 user=util_user password=* monitor_interval=1000 auto_failover=true auto_rejoin=true

[MaxAdmin-Listener] type=listener service=MaxAdmin-Service protocol=maxscaled socket=default

[MaxAdmin-Service] type=service router=cli

[Read-Write-Listener] type=listener service=Read-Write-Service protocol=MariaDBClient port=3306 address=0.0.0.0

[Read-Write-Service] type=service router=readwritesplit servers=db1,db2 user=util_user password=** filters=HiFi enable_root_user=1 connection_keepalive=30s

[HiFi] type=filter module=hintfilter

[QLAFilter] type=filter module=qlafilter filebase=/var/log/maxscale/qla.log match=/.*/ flush=true log_data=service, session, date, user, reply_time, query log_type=unified newline_replacement=" LANG "