What's going on with Failed to read FastCGI header?

there are a lot of errors in the log that Failed to read FastCGI header does not understand under what circumstances. On the surface of the website, there is no access exception

.
Php
Mar.14,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e50a7f-44612.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e50a7f-44612.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?