Hi everyone,
Bump. Can anyone help with why IPVS is not respecting the subnet
persistence granularity?
Thanks,
Abhijeet
On Thu, Aug 15, 2019 at 1:11 PM Abhijeet Rastogi <abhijeet.1...@gmail.com>
wrote:
> Hi everyone,
>
> I'm investigating a typical configuration for an L4 TCP load balancer
> using ipvs+keepalived. Settings:-
>
> persistence_timeout: 120 seconds. (# LVS persistence timeout, sec)
> /sbin/ipvsadm --set 1800 120 300 (30 min timeout for TCP)
> persistence_granularity: "48" for ipv6.
> lb_algo: rr (round-robin)
>
> My expectation is, all the IPs from the same /48 v6 subnet should always
> reach the same real_server because of setting granularity. (at least the
> connections created in last 120 seconds)
>
> However, I can see that established connections from the same /48 v6
> subnet are spread across multiple reals, even for recently established
> connections.
>
> # Same /48 going to different reals, (very recent connections)
> 1. Grepping with only first 3 quibble to see how a /48 is being
> distributed.
> 2. " | grep ESTAB | grep 29: | head -n 100" to only see first 100
> established connections created in last 60 seconds as my timeout is set to
> 30:00 (1800 seconds)
> 4. 6th column is the real IP.
> I see that the same /48 is getting distributed across multiple different
> reals. (should be same real because of persistence_granularity set to 48).
> $ sudo ipvsadm -lnc | grep "xxxx:xxxx:xxxx" | grep ESTAB | grep 29: | head
> -n 100 | awk '{print $6}' | sort | uniq -c
> 2 [V6IP_REDACTED:9222]:443
> 9 [V6IP_REDACTED:9223]:443
> 7 [V6IP_REDACTED:9224]:443
> 13 [V6IP_REDACTED:9225]:443
> 1 [V6IP_REDACTED:9226]:443
> ............
> ............ output redacted
>
>
> - Why are recent connections going to different reals?
> - For recent connections, shouldn't they always end up on same real?
> - For older connections, I guess, persistence_timeout causes the
> traffic to balance to other reals via round robin.
>
>
> Thanks in advance!
> --
> Cheers,
> Abhijeet (https://abhi.host)
>
--
Cheers,
Abhijeet (https://abhi.host)
_______________________________________________
Please read the documentation before posting - it's available at:
http://www.linuxvirtualserver.org/
LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org
Send requests to lvs-users-requ...@linuxvirtualserver.org
or go to http://lists.graemef.net/mailman/listinfo/lvs-users
