[ZODB-Dev] RelStorage - high ConflictError rate in newly converted DB

[Shane Hathaway]

On 11/07/2011 03:15 PM, Darryl Dixon - Winterhouse Consulting wrote:
> Hi All,
>
> We have just converted a site with a handful of editors over from ZEO to
> RelStorage on Oracle and and the rate of ConflictErrors has gone through
> the roof (5 an hour average continuously for days). This seems very
> surprising to me. What options/changes should we look at configuring to
> lower this back down? We used to use ZEO with an invalidation-queue-size
> of 5000 and a client-cache of 1000. Currently we are using a very basic
> RelStorage configuration without any additional bits like memcache.
>
> Any guidance gratefully appreciated.

I have a few thoughts:

- You aren't using poll-interval, are you? Make sure that is disabled.

- When you switched from ZEO to Oracle without turning on memcache, you 
lost the ZEO cache and didn't replace it with anything, so now loading 
objects takes longer, which may lead to more conflicts. I would try 
turning on memcache.

- Do you have multiple storages / databases? Make sure each uses a 
different Oracle lock ID.

Shane