DMZ Server dropping connection to mySQL

[jouwstrab]

Our DMZ server is dropping its connection to the internal server hosting mySQL and our JSS instance. There are no issues internally, but currently it is impossible for devices to "check-in" off site. This is creating an issue every morning when all 3500+ devices check back in after being away for 15 hours.

Now, I've done some testing and it seems that when not under load things are okay, as in if I restart the server and then go out into world and try downloading apps offsite everything works. However, when all the students go home for the day it fails almost immediately. The error we are receiving is "Tomcat -44 SqlExceptionHelper -SQL Error 1220, SQL State: 08000" and then the next line "Connection is close." So it seems that we are unable to connect to the Database successfully, our max connections are set at 200 and the max connections on the internal server is set at 90 and 50 on the external, so we should never be breaching the max allowed.

Anyone have suggestions as to what could be causing our issues?

[franton]

Firewall / Proxy. If it works for a while then drops like that, there's a rule somewhere that dislikes the amount of traffic coming in.

[jouwstrab · Accepted solution]

Thanks for the response @franton

After working with JAMF for a few days we found out that connection was being terminated because of a bad upgrade to 9.96 which left the external server trying to communicate to the database using 9.92 "protocol."