Re: Unconsumed replog causes slapd to shoot to 100% cpu?

[Jeff Leung <jeffleung@mac.com>]

I don't believe slurpd was shut down, but maybe it just died or got hung on
its own (hard to tell since it either was no longer running or was not
responding to SIGTERM when the load was noticeably high).

Are you sure that slurpd will continue to consume the replog if it has no
replicas to write to? If so, then where does that data go? Is it just lost
(because that isn't the behavior we're looking for, since we can't guarantee
that a replica will always be up)?

Thanks.

On 1/23/04 9:17p, "Quanah Gibson-Mount" <quanah@stanford.edu> wrote:

> 
> 
> --On Friday, January 23, 2004 9:02 PM -0800 Jeff Leung <jeffleung@mac.com>
> wrote:
> 
>> Hi,
>> 
>> Recently I reported that our slave instances (openldap-2.1.22 over
>> BerkeleyDB.4.1.25) were occasionally reaching 100% cpu time.
>> 
>> I tried upgrading our test boxes to use openldap-2.1.25 and BerkeleyDB
>> 4.2.52-1 a little bit afterwards. However, we ran into the same problems,
>> but this time with the masters.
>> 
>> The interesting thing is that this only happened a while after we shut
>> down the slaves. The resulting unconsumed replogs became huge (several
>> hundred megs). We thought back about it and noticed that this was
>> happening to our slaves as well when they hit 100% cpu usage (we have
>> replication done in two stages, once from the master to slaves, and then
>> from the slaves to a set of backup slaves).
>> 
>> Does anyone know what the effect of an oversized replog is on a slapd? Is
>> it possible that if the replog gets big enough, slapd spends too much time
>> writing new data to the replog to service requests, or some other behavior
>> that would cause load to shoot up to 100%?
> 
> Jeff,
> 
> Did you turn off slurpd or something?  You can leave slurpd running, even
> if its replicas are shut down -- That is the process that clears out the
> slapd created replog...
> 
> --Quanah
> 
> --
> Quanah Gibson-Mount
> Principal Software Developer
> ITSS/TSS/Computing Systems
> ITSS/TSS/Infrastructure Operations
> Stanford University
> GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html
> 
> 

-- 
Jeff
// Diplomacy is the art of saying 'nice doggy'
// until you can find a rock.