Re: memcached with ccache

> On Thu, Jun 20, 2013 at 11:03 PM, Pierre Tardy <[email protected]> wrote:
>
>> Hi,
>> Back in 2010, there has been some question about supporting memcached as
>> a backend for ccache:
>> https://github.com/jrosdahl/ccache/pull/30
>>
>> On Thu, Jun 20, 2013 at 11:03 PM, Pierre Tardy <[email protected]> wrote:
>
>> Hi,
>> Back in 2010, there has been some question about supporting memcached as
>> a backend for ccache:
>> https://lists.samba.org/archive/ccache/2010q4/000686.html
>>
>>
>> Looks like this thread hasn't result in code, and I did take a few days
>> to make an attempt at it.
>>
>> Here is the first working code:
>> https://github.com/jrosdahl/ccache/pull/30
>>
>
FWIW, I've been able to make some extensive testing of this.

I've been running 6 big xeon machines, building our Android trees over and
over (50+ different configuration), and this ccache version.
Each machine was configured with memcached, with 20GB cache size, and 16MB
max object (option -I 16m)
The cache did quickly warm up and then build time decreased slightly less
time as with mainline ccache.

The big difference is that my cache hit was much better. Once a patch has
been built in one build slave, its cached result is available for the other
slave instantly.

The size of the cached object files for one build is about 5GB, it
transfers without too much issue during the 5 mins of the c/c++ build on
1GBit ethernet.

We are pretty happy with this, as this doubles our build capacity, and will
put it in prod in the next few weeks.
I would appreciate getting some reviews.


Regards,
Pierre