Aborted_Connects Increasing – Causing High Percentage Of Refused Conne

by Feb 8, 2013

We have a php/mysql web application and we use monyog to monitor the mysql portion of it. We have multiple server environments, some of which use Debian + Mysql, some use Windows + Mysql.

I have noticed, once I add one of our servers in Monyog, the number of aborted_connects steadily increases over time on that server. I have monitored aborted_connects on servers that are not monitored by monyog, and these servers have aborted_connects = 0. Once I add that server to monyog, aborted_connects starts to increase.

I understand that the "Percentage of refused connections" counter in monyog is calculated by aborted_connects divided by connections. As such, the "percentage of refused connections" steadily climbs to high percentages in off-hours when the application is lightly used, because the number of connections decreases, while the aborted_connects stays the same, therefore increasing the percentage.

I am trying to find out why monyog is causing aborted_connects. I have enabled log_warnings=2 on all of my monitored servers. On my Windows + Mysql server, I do not notice any warnings of note. However, on my debian + mysql servers, I have many entries of the following errors:

[Warning] Aborted connection 154246 to db: 'unconnected' user: 'monyog' host: 'xx.xx.xx.xx' (Got timeout reading communication packets)

[Warning] Aborted connection 154228 to db: 'unconnected' user: 'monyog' host: 'xx.xx.xx.xx' (Got an error reading communication packets)

Obviously, when I disable the monitoring of the debian servers, these errors disappear. Please help me find the cause of all of the aborted_connects by monyog, which are causing false numbers for percentage of refused connections.