Knowledge Base

Plesk shows 502 Bad Gateway error and service sw-engine is marked as stopped

Symptoms

Plesk shows 502 Bad Gateway error
The service sw-engine is not running:

# service sw-engine status
● sw-engine.service - Startup script for Panel sw-engine
Loaded: loaded (/usr/lib/systemd/system/sw-engine.service; enabled; vendor preset: disabled)
Active: inactive (dead) since Mon 2018-03-26 21:57:49 +07; 5min ago

# systemctl status sw-engine -l
● sw-engine.service - Startup script for Panel sw-engine
Loaded: loaded (/usr/lib/systemd/system/sw-engine.service; enabled; vendor preset: disabled)
Active: activating (auto-restart) (Result: exit-code) since ma 2022-07-11 11:31:10 -3; 2s ago

Cause

sw-engine service is stopped. This may occur if the server has no free disk space, an upgrade attempt was unsuccessful or the service was stopped manually.

Resolution

Free up disk space on the server
Restart Plesk sw-engine service
Using Plesk Repair Kit
1. Click Open Repair Kit and log in with Plesk admin credentials.
2. If it was successful, try starting sw-engine service by clicking Restart Processes
3. If it was successfully started, click Log In to Plesk button
Using SSH
1. Connect to the server via SSH
2. Start sw-engine service:
  
  # service sw-engine start
  
  Or start psa service:
  
  # service psa start