Symptoms After Plesk upgrade to version Plesk 12x:
1. 502 Bad Gateway error while accessing Plesk.
2. From /var/log/sw-cp-server/error_log log
[error] 29224#0: *99 recv() failed (104: Connection reset by peer) while reading response header from upstream, client, server: , request: "GET /admin/home/admin HTTP/1.1", upstream: "fastcgi://unix:/var/run/sw-engine.sock:", host: "plesk.example:8443", referrer: "https://plesk.example:8443/"
CauseObsolete sw-mariadb-client package:
# dpkg -l |grep maria
ii sw-mariadb-client 1.0.0-13060717 Mariadb client library
Resolution 1. Make sure that version of sw-mariadb-client corresponds to the latest in Plesk repository
http://autoinstall.plesk.com/PSA_12.0.18/dist-*****/contrib/ . Download and install it, if the version is old:
For example, for Ubuntu 12.04 ,x386:
# wget http://autoinstall.plesk.com/PSA_12.0.18/dist-deb-Ubuntu-12.04-i386/contrib/sw-mariadb-client_1.0.0-14033112_i386.deb
# dpkg -i sw-mariadb-client_1.0.0-14033112_i386.deb
# dpkg -l |grep maria
ii sw-mariadb-client 1.0.0-14033112 Mariadb client library
1. Restart sw-cp-server service:
/etc/init.d/sw-cp-server stop
/etc/init.d/sw-cp-server start