improving concurrency/performance

[Sergio Devojno Bruder]

Michael Loftis wrote:
>>
>> Interesting ... can you provide some numbers, even from memory?
> 
> I'd also be VERY interested since our experience was quite the opposite. 
> ReiserFS was faster than all three, XFS trailing a dismal third (also 
> had corruption issues) and ext3 second or even more dismal third, 
> depending on if you ignored it's wretched large directory performance or 
> not.  ReiserFS performed solidly and predictably in all tests.  Not the 
> same could be said for XFS and ext3.  This was about 2 yrs ago though.

Our cyrus in production have one diff from stock cyrus, I almost forgot: 
we tweaked the directory hash functions, we use a 2 level deep hash, and 
that can make a lot of a diferente specially comparing FS's.

We tweaked our hash function specially to guarantee that our users 
directories will in the vast majority of the cases will occupy only one 
block with ext3 (4k).

--
Sergio Devojno Bruder