[Koha] Koha Server going down occasionally

Hi, Our koha server seems to be going down once every week on an average. Staff can log in, but can't do anything from there. Similarly, the OPAC main page comes up, but when I try to do something I get a "503 Service Unavailable". Here are the logs corresponding to the issue: https://paste.ubuntu.com/23131505/ I tried googling for a fix, but could not find anything. Hope someone can shred some light on this. Dalton