What is a "full dump" and a "full sync"?

[RincewindsHat]

Recently we had alarms at a customer where the icingadb CheckCommand went critical becaus the "full dump" took longer than 10 minutes (which might be a problem there or a bug since the normal ones take two seconds).
To truelly understand the problem I went to find out what a "full dump" really is and what is does, but was not able to find anything (neither the docs nor git grep dump in this repo reveiled anything directly).

Could someone explain to me what a "full dump" exactly is, when it should happen and what the consequences of this error pattern actually are?

I would be happy to write some documentation, but I need someone to give me some hints.

[julianbrost]

Full dump refers to Icinga 2 writing its whole config to Redis each time it reconnects to it.

[RincewindsHat]

And that is only the Icinga 2 -> Redis part or is there some followup interaction regarding IcingaDB -> SQL DB?

[RincewindsHat]

Additionally: If that will take a long time, there is probably a problem with Redis?

[RincewindsHat]

Also (sorry for being nosy): What is the "full sync"? I think I confused that with the "full dump".

[julianbrost]

And that is only the Icinga 2 -> Redis part

That's what the CheckCommand icingadb attributes to full dump.

or is there some followup interaction regarding IcingaDB -> SQL DB?

That exists but isn't counted towards the dump. That's the full sync (so that should answer your last question as well). That's basically comparing what's in Redis and the relational database and applying the changes.

Additionally: If that will take a long time, there is probably a problem with Redis?

That's one possibility. The problem will be somewhere in Icinga 2, in Redis, or the connection between the two.

[RincewindsHat]

Thank you for the explanation