[openib-general] SA cache design

[Sean Hefty]

Eitan Zahavi wrote:
> Is the intention to speed up SA queries?
> Or is it to have persistent storage of them?

I want both.  :)

> I think we should focus on the kind of data to cache,
> how it is made transparently available to any OpenIB client
> and how/when is it invalidated by the SM.
> We should only keep the cache data in memory not on disk.

In order to support advanced queries efficiently, some sort of indexing scheme 
would be needed.  This is what a database system would provide, saving us from 
having to implement that part.  The fact that the database could also provide 
persistent storage and triggers are just additional advantages.

> Later if we want to make it persistent or even stored in LDAP/SQL...
> I do not care. But the first implementation should be in memory.

I think that you're assuming that an initial implementation that is done just in 
memory would be quicker to complete.  I'm not really wanting to write a complete 
throw-away solution capable of supporting only one or two very simple queries 
efficiently.

> BTW: most of the databases referred by these mails are not supporting
> distributed shadow copies of a centrally controlled tables.

Personally, I'd be happy with a simple database that provided nothing more than 
indexing and query support.

- Sean