[Zope] Re: MySQL thread connection question

[Chris Withers]

Allen Schmidt wrote:
> I think it is ZEO that keeps them alive because if we kill and restart 
> ZEO along with the clients the the number of mysql threads drops to 
> almost nothing and then starts building back up as the clients reconnect 
> each Zope client thread to each database connection.

ZEO has nothing to do with MySQL threads ;-)

Only the ZEO clients and not the storage server will open connections to 
MySQL. When you restart the client it should drop all the connections...

> Has anyone seen "too many" mysql connections from Zope?

Not MySQL, but look through the archives of zope-db at zope.org for lots of 
discussion of this problem..

> What if we add 
> more ZEO clients on the same or different servers? And each with 6 or 7 
> Zope threads...and each have the same number of database connections? 

Well, then you have a helluva lot of MySQL connections ;-)
It largely depends how ZMySQLDA manages its connections to MySQL, and 
you'd have to ask Andy Dustman about that...

> Hundreds of MySQL connections... That seems it can only cause more 
> problems. Just not sure.

Yep, 'cos if it works like most DA's, only a fraction of those will ever 
get used, and the rest will just hang around doing nothing :-(

cheers,

Chris

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