From: Nicolas Pitre <nico@cam.org>
Date: Wed, 13 Aug 2008 17:57:59 GMT
Subject: Re: pack operation is thrashing my server
Message-ID: <alpine.LFD.1.10.0808131352260.4352@xanadu.home>
In-Reply-To: <a6b6acf60808131038s1ae7fb69s2b703c25766a82c0@mail.gmail.com>

On Wed, 13 Aug 2008, Ken Pratt wrote:

> > As for how to estimate entropy, isn't that just a matter of feeding it
> > through zlib and compare the output size to the input size? Especially
> > if we're already about to feed it through zlib anyway... In other
> > words, feed (an initial part of) the data through zlib, and if the
> > compression ratio so far looks good, keep going and write out the
> > compressed object, otherwise abort zlib and write out the original
> > object with compression level 0.
> 
> This is probably off topic now, but as the OP, I'd like to mention
> that I tried setting pack.compression = 0 and it did not solve my
> memory issues.

Yeah, the compression level is a tengential issue which has to do with 
speed.

> So it seems to be that the packing itself that is
> sucking up all the memory -- not the compression.

Initial packing requires enough memory.  And if your repository is not 
packed, then every clone request will act just like a first packing. So 
for git on a server to behave well, repositories have to be well packed.


Nicolas