|
> Hello all,
>
> I am running pulse on virtual machine for webserver, it seems working
> well, but there is one problem with networking I think. It seems there
> is a problem with lvs server is not fragmenting larger than 1500
> packets size. I did the quick tcpdump and I get following info.
>
> my problem is when user is uploading files it takes for ever and never
> completes. I am thinking lvs (pulse) is not not fragmenting the larger
> packet size than 1500 hence it never goes to backend server.
>
> 16:25:22.543563 00:1f:6d:cf:4e:49 > 52:54:00:b5:30:3c, ethertype IPv4
> (0x0800), length 2974: 10.128.1.5.60715 > 10.192.6.1.https: Flags [.],
> seq 7705:10625, ack 146, win 16388, length 2920
> 16:25:22.543590 52:54:00:b5:30:3c > 00:1f:6d:cf:4e:49, ethertype IPv4
> (0x0800), length 590: 10.192.6.1 > 10.128.1.5: ICMP 130.208.165.177
> unreachable - need to frag (mtu 1500), length 556
>
> I tested following:
>
> 1. IP forward is enabled.
> 2. lro,gro are off on eth0
> ethtool -k eth0
> Offload parameters for eth0:
> rx-checksumming: on
> tx-checksumming: on
> scatter-gather: on
> tcp-segmentation-offload: on
> udp-fragmentation-offload: on
> generic-segmentation-offload: on
> generic-receive-offload: off
> large-receive-offload: off
> 3. IPVS version is v1.2.1
> 4. Backend server has arptables and set to mangaled to right interface
> 5. Firewall is allowed on both lvs and backend server.
> 6. http and https are open for all.
>
> Any help in this would be great.
It seems that the LVS cannot send out the packet since the MTU is too large
for the 1500 Byte of the interface. Please don't be confused by the length of
2974 byte that tcpdump shows. tcpdump just sees the packet on the wrong point
on the chain.
Be sure the Path MTU discovery works or clear the DF bit of the packet
entering the load balancer.
Greetings,
--
Dr. Michael Schwartzkopff
Guardinistr. 63
81375 München
Tel: (0163) 172 50 98
Fax: (089) 620 304 13
signature.asc
Description: This is a digitally signed message part.
_______________________________________________
Please read the documentation before posting - it's available at:
http://www.linuxvirtualserver.org/
LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
or go to http://lists.graemef.net/mailman/listinfo/lvs-users
|
