[ovs-dev] [PATCH v3 ovn 0/2] ovn-controller: Logical flow processing optimizations

[Mark Michelson]

Acked-by: Mark Michelson <mmichels at redhat.com>

On 9/12/19 10:13 AM, Dumitru Ceara wrote:
> This series adds some (independent) optimizations that improve
> ovn-controller performance by lowering the number of operations that
> need to be executed during a iteration of the main controller loop.
> 
> Each patch in the series addresses a bottleneck reported by running
> `perf record -g --call-graph dwarf -i /usr/bin/ovn-controller` on a
> system where the Southbound DB was already populated by ovn-northd.
> 
> The logical configuration of the OVN is:
> - 500 logical routers
> - 1 logical switch attached to each router
> - 2 logical ports attached to each switch
> - 4 ACLs per switch
> 
> To evaluate the performance impact of the change in a more realistic
> way the following test is performed (on a single node that runs ovn-northd
> and ovn-controller and emulates the VM hosts with OVS internal interfaces):
> 1. Start ovs-vswitchd.
> 2. Remove the Southbound DB such that ovn-northd needs to repopulate
>     everything based on the Northbound DB contents.
> 3. Start a patched version of ovn-controller such that it tracks loop time
>     execution information and how long it takes to process all logical flows
>     from the Southbound DB.
> 4. At the same time with step 3 above, start ovn-northd which will populate
>     the Southbound DB.
> 
> The following measurements are taken:
> - real time (measured with `time`) to have all corresponding openflow flows
>    processed by ovs-vswitchd.
> - maximum ovn-controller main loop iteration duration
> - average ovn-controller main loop iteration duration
> - number of times ovn-controller executes the main loop until all logical
>    flows are processed
> 
> Comparing the results before and after this series we see:
> - 13% performance boost w.r.t. real time taken to have all openflow flows
>    installed in ovs-vswitchd
> - 41% decrease of average ovn-controller loop iteration duration and
>    12% increase of ovn-controller number of loop iterations. Essentially
>    processing loops are faster and can happen more often.
> - 2% decrease of maximum ovn-controller main loop iteration duration.
> 
> 
> Dumitru Ceara (2):
>        ovn-controller: Optimize update of ct-zones external-ids.
>        ovn-controller: Minimize SB DB port_binding lookups.
> 
> 
>   controller/binding.c        |   19 ++++++++++++---
>   controller/ovn-controller.c |   53 +++++++++++++++++++++++++++++++++++++------
>   controller/ovn-controller.h |   11 ++++++++-
>   controller/physical.c       |   17 ++++++++------
>   controller/pinctrl.c        |   53 +++++++++++--------------------------------
>   5 files changed, 93 insertions(+), 60 deletions(-)
> 
> 
> ---
> v3:
>    - Remove first patch from the series as it was already applied.
>    - Rebase rest of series.
> v2: Send series for OVN repo instead of OVS.
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