[Bucardo-general] Bucardo vs. rubyrep

[Udo Rader]

On 09/08/2010 03:51 PM, Greg Sabino Mullane wrote:
> There is no way to do this more intelligently with trigger based 
> systems, so the answer is that there will be one entry in the bucardo_delta 
> table for every row which changed.
> 
>> UPDATEs like these have caused most of our headache, because first they
>> completely stalled the replication process and then finally killed it
>> (because the amount of memory required to deal with such a huge number
>> of pending changes just does not seem to exist).
> 
> If you are using master -> slave (pushdelta) this is not very much of a 
> problem. The current master <-> master (swap) system will use a lot of 
> resources, although the next version of Bucardo will solve this.

Thanks for your answer.

Any ETA of this next version resp. is it already in a testable state? If
so, I would be willing to give it a try on our staging databases.

>> Occasionally, some applications will "update" a record even though the
>> data has not changed.
> ...
>> Does bucardo utilize this functionality (thus reducing the amount of
>> replicated data)?
> 
> No: this is a feature, not a bug. Think about triggers that fire on 
> the table and update other tables, for instance. However, if you 
> really want that behavior, it is possible by writing a custom 
> trigger to populate bucardo_delta based on your own criteria.

Ok, I see, even though it would be nice to be a feature that could
easily be switched off then :-)

>> Is there a way to roughly calculate the memory requirements for bucardo,
>> especially for a situation where the nodes have been disconnected for
>> some time and need to resynchronize?
> 
> At the very least, it's going to need to read in all the rows that have 
> changed, so start from there, then add 50% :)

Hehe, well, that's exactly what I ment by "rough estimation" :-)

> My company (End Point) provides support, as do most of the other well 
> known Postgres consulting companies. I know EnerpriseDB has been investigating 
> Bucardo for some time, but I don't know if they offer explicit support 
> for it.

Well, that sounds excellent then. Do you have something like support
plans or something including rates that you could send me?

Thanks a lot!

-- 
Udo Rader, CTO
http://www.bestsolution.at
http://riaschissl.blogspot.com