Re:March 20 ChatGPT outage: Here’s what happened
by nijave on Friday March 24, 2023 @05:01PM
(#35295444)
A pretty small Redis server can handle 10k clients and saturate a 1Gbps NIC. You'd need a pretty heavy duty Postgres database and definitely need a connection pooler to come anywhere close.
Re:March 20 ChatGPT outage: Here’s what happened
by anarazel on Friday March 24, 2023 @05:51PM
(#35296130)
I agree that redis can handle some query volumes and client counts that postgres can't.
But FWIW I can easily saturate a 10GBit ethernet link with primary key-lookup read-only queries, without the results being ridiculously wide or anything.
Because it didn't need any setup, I just used:
SELECT * FROM pg_class WHERE oid = 'pg_class'::regclass;
Re:March 20 ChatGPT outage: Here’s what happened
by e12e on Saturday March 25, 2023 @10:21AM
(#35302896)
> SELECT * FROM pg_class WHERE oid = 'pg_class'::regclass;
This selects every column (*) from every table (ObjectID is of type regclass)?
Re:March 20 ChatGPT outage: Here’s what happened
by anarazel on Saturday March 25, 2023 @11:15AM
(#35303467)
Sorry, I should have used something more standard - but it was what I had ready...
It just selects every column from a single table, pg_class. Which is where postgres stores information about relations that exist in the current database.
Re:March 20 ChatGPT outage: Here’s what happened
by hobobaggins on Friday March 24, 2023 @06:47PM
(#35296713)
and those have reliable backup/restore infrastructure. Using redis as a cache is fine, just don't use it as your primary DB.
#2 is an interesting point. When you benchmark, the normal process is to just set up a database then run a shitload of queries against it. I don't think a lot of people put actual production load on the database then run the same set of queries against it...usually because you don't have a production load in the prototyping phase.
However, load does make a difference. It made more of a difference in the HDD era, but it still makes a difference today.
I mean, redis is a cache, and you do need to ensure that stuff works if your purge redis (ie: be sure the rebuild process works), etc, etc.
But just because it's old doesn't mean it's bad. OS/390 and AS/400 boxes are still out there doing their jobs.