Starting APIM 5.6 the cluster can set net_read_timeout and  net_write_timeout variables when mysql pod get started/restarted. https://docs.tibco.com/pub/apim-local/5.6.0/TIB_apim-local_5.6.0_relnotes.pdf
Lets see where these fields are configured and how to find them within the cluster to update/modify their values. 
 

In this article we will learn how to find and/or update the automated net_read_timeout/net_write_timeout variables when MySQL pods get started/restarted in ML5.6

ANY

After deployment in SQL pod net_read_timeout and net_write_timeout values are added in my.cnf and ml_sql_properties_final.json files.

[restricted@37d6007f050c ~]$ cat /opt/mashery/containeragent/resources/properties/tml_sql_properties_final.json | grep net "net_write_timeout" : "120",
"net_read_timeout" : "60",
[restricted@37d6007f050c ~]$
[restricted@37d6007f050c ~]$cat /etc/my.cnf | grep net
net_read_timeout=60
net_write_timeout=120

Also using cm set config command the default values can be changed.

Below we updated net_write_timeout to 180

[restricted@e7582a6e23db ~]$ cm set config --componentType sql --prop net_write_timeout --value 180

Successfully set configuration property for the scope map[zone:local] for components of type sql