[j-nsp] Junos 20 - slow RPD

[Mihai]

Hi Saku,

The routes are in VRF so no support for rib-sharding unfortunately.
This MX204 is running 20.2R3-S3 so probably the only option is to try 
another version.

Thank you for your time and info, very useful as always.

On 22/03/2022 17:58, Saku Ytti wrote:
> Hey,
> 
>> On MX204 with ~4M routes, after upgrading from 18.2 to 20.2 the RPD is
>> way slower in processing BGP policies and sending the routes to neighbors.
>> For example, on a BGP group with one neighbor and an export policy
>> containing 5 terms each matching a community it takes ~1min ( 100% RPD
>> utilisation ) to send 1k routes to the neighbor in 20.2 compared to 15s
>> in 18.2.
>> Disabling terms will reduce the time.
>>
>> Anyone experienced something similar?
> 
> I don't recognise this problem specifically. It seems rather terrible
> regression so you probably should either open a JTAC case or do the
> Junos dance. If you have a large RIB/FIB ratio allowing more than 1
> core to work on BGP will produce improvement:
> 
> set system processes routing bgp rib-sharding number-of-shards 4
> set system processes routing bgp update-threading
> 
> This is a disruptive change. JNPR wanted us on 20.3 (we are on
> 20.3R3-S2) for rib-sharding, but we did run it previously on 20.2R3-S3
> with success. We are currently targeting 21.4R1-S1.
> 
> If you have memory pressure, you can expand the default 16GB DRAM to
> 24GB DRAM via configuration toggle (post 21.2R1). If you are
> comfortable hacking QEMU/KVM config manually, you can do it on any
> release and can entertain other sizes.
>