Aborted connection ... (Got an error reading communication packets)

[bnchdan]

Description:
When using lua-resty-mysql with MariaDB, I see frequent warnings in syslog:

[Warning] Aborted connection … (Got an error reading communication packets)

This happens both when using db:set_keepalive(timeout, pool_size) and when using db:close() after queries.

Is this expected behavior?
Are there best practices to avoid these syslog warnings while safely closing or reusing connections?

[zhuizhuhaomeng]

Would you please use tcpdump to capture the full session so we can analyze this issue？

[bnchdan]

I’ve retested, and:

1) If i am using ip and port the warning appears only when using set_keepalive

If I set the timeout to 10 seconds, the warning appears in the syslog after 10 seconds. The warning occurs once for every Nginx worker that uses db:set_keepalive(timeout, pool_size).

2) If i am using sockets

Apears when using db:close and db:setkeepalive

I am using Nginx with Lua (libnginx-mod-http-lua, not OpenResty). The library is installed manually, and I am loading it via the path.

[zhuizhuhaomeng]

I think this issue is related to the version of MariaDB.
We need the pcap to analyze this issue.