[ovs-dev] Multi-threaded OVSDB

[Valentine Sinitsyn]

On 16.03.2017 20:56, Ben Pfaff wrote:
> On Tue, Mar 14, 2017 at 07:08:54PM +0500, Valentine Sinitsyn wrote:
>> Recently, I was evaluating a multi-threaded OVSDB/ovn-northd design, and
>> came across the patchset [1].
>>
>> Looks like this RFC patchset was received well, but never completed. What's
>> the reason? No real performance benefits, lack of interest, other
>> high-priority tasks or whatever?
>
> It's kind of a combination of those.  Andy got preempted by other
> higher-priority work, plus it's unclear whether threading ovsdb-server
> solves an important problem at this time.  I'm currently working on
> adding clustering support to OVSDB, which ought to allow scaling out
> reads, which are most of the OVN workload, so that might solve the same
> problem in a different way.
This sounds promising. Are you planning something Mongo-like, that is, 
one server writes should be directed to, and all servers serving reads? 
In our tests, it takes about half an hour (and a few hundred reconnects) 
to send an initial snapshot of a large southbound database to 1000+ OVN 
2.7 controllers. This makes disaster recovery plan a pain. Should we 
expect things to get better here (we can probably contribute to this, if 
feasible)?

As for multi-threaded OVSDB, the latest patch series I found in Andy's 
fork segfaults just after startup, so we can't even do a quick test to 
check if it makes things better for us or not.

Thanks,
Valentine