On Fri, Jun 05, 2015 at 11:17:49AM +0200, Klaus Aehlig wrote:
> The first thing the newly forked job will do anyway is
> to update its job file as the first op-code is now waiting.
> It is enough that this information is replicated to all
> master candidates. Note that a local change of the livelock
> file will not be helpful to other master candidates, as
> the livelock has only a meaning on the current node anyway.
> 
> This seemingly little saving of two replications is significant,
> however, as it happens under the fork lock by which we avoid
> two forks at the same time, as this can cause problems with the
> Haskell runtime.
> 
> Signed-off-by: Klaus Aehlig <[email protected]>
> Reviewed-by: Petr Pudlak <[email protected]>
> 
> Cherry-picked-from: 7684a50192bb
> Signed-off-by: Klaus Aehlig <[email protected]>
> ---
>  src/Ganeti/JQScheduler.hs | 2 +-
>  src/Ganeti/JQueue.hs      | 8 ++++----
>  2 files changed, 5 insertions(+), 5 deletions(-)

This patch has a significant impact on the throughput of the job
queue, especially in larger clusters. As it is quite an insulated
change with understood effect, and can cleanly be cherry-picked
down to stable-2.13 (the relevant code hasn't changed since then),
I think it is safe to cherry pick.

-- 
Klaus Aehlig
Google Germany GmbH, Dienerstr. 12, 80331 Muenchen
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