HwKeeper
Auto-translated
On April 13-14, the server was diagnosed by the hosting provider.
After that, I compared the statistics for two periods:
1) before restoring the file system resources, updating the software, and performing the diagnosis.
2) after.
The results are good.
Starting from April 15, when the restoration work was completed and the server diagnosis by the hosting provider was finished, errors 502 and 504 are approaching zero.