Knowledge Base

Plesk is unresponsive periodically: Unable to write to stream: fwrite(): send of 4 bytes failed with errno=10054 An existing connection was forcibly closed by the remote host.

Symptoms

Plesk interface is unresponsive, after some time the following error is shown in a web-browser:
HTTP ERROR 500
The site can't be reached
the connection was reset.
The following error message appears in the Plesk log %plesk_dir%adminlogsphp_error.log:
ERR [panel] Unable to write to stream: fwrite(): send of 4 bytes failed with errno=10054 An existing connection was forcibly closed by the remote host.

Cause

This is a MariaDB Connector bug with ID CONC-518.

Resolution

Until the bug is resolved, apply one of the following temporary workarounds:

Using Plesk Reconfigurator

Connect to the Plesk server via RDP.
Start Plesk Reconfigurator at Windows Start Menu > Plesk Reconfigurator.
Click Repair Plesk Installation > select Plesk services > click Check.

Restart services manually

Connect to the Plesk server via RDP.
Open Plesk Services Monitor from Windows Tray.
Select Plesk Management Service and click Restart.
Start Internet Information Service Manager (IIS) and navigate to SERVER_NAME > Application Pools.
Select application pool PleskControlPanel and click Recycle.