[OpenSER-Users] openser + mysql clusters

[Stanisław Pitucha]

----- "Sajith T S" <sajith at gmail.com> wrote:
> How is the overall experience like re. deploying openser with mysql
> clusters?

Good enough. Just setup A record pointing at 2 or more api nodes and set them up with virtual ips (heartbeat works quite well...). Openser will recover if one of the nodes fail.

> Are there gotchas etc that need to be taken care of?  (For
> example, a 2006 article [1] says that "The MySQL NDB engine currently
> runs its database completely in memory. This means that you have to
> be
> able to fit your database in memory."  But this is not documented as
> a
> limitation in mysql faq.)

It's a feature and it's in the first sentence of cluster overview: "... enables clustering of in-memory databases" ;)
Gotchas:
- don't bother with 5.0 - it's got strange issues
- 5.1.23 was the last version of 5.1.X with ndb. Now you have to compile carrier grade edition from source.
- ping database once in a while (every database in a cluster) by *writing* to some table. ndb sometimes just locks itself, but allows selects (locks internally - I've never used lock statements). Restarting api node is enough in that case.
- No schema change needed - it just works with standard tables.
- Inserts / updates will be slower - not much, but anyway.
- hang out in #mysql-ndb channel on freenode -> you'll learn some magic ndb-mgm commands which are sometimes not documented.

Otherwise, it's not that different from a standard mysql database.

---
Stan