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Hi,
I am a long-time user of LVS, but now I've got a problem that I can't
seem to solve. Searching the HOWTO and the web hasn't given me anything
useful, so I turn to the experts now ;-)
I have a quite straightforward LVS-DR setup: two machines, both running
a webserver on port 80, one of them directing traffic to either the
local node or the other machine. I am using the 'sh' scheduler, as I
have been for ages.
Since a while, directing traffic to the other machine (not the director)
doesn't work anymore, BUT ONLY on a specific VIP:PORT combination.
During my tests, the LVS setup is as follows:
martijn@whisky:~> rr ipvsadm -L -n
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 213.207.104.20:80 sh
-> 213.207.104.11:80 Route 500 0 0
TCP 213.207.104.20:81 sh
-> 213.207.104.11:81 Route 500 0 0
TCP 213.207.104.50:80 sh
-> 213.207.104.11:80 Route 500 0 0
Note that all references to the local node have been temporarily
removed. Now, the service defined second (port 81) works. The third one,
port 80, but a different VIP, works too. The first one, the one that I
need, does not.
When I connect to 213.207.104.20:80, I see some kind of SYN storm on
both the director and the real server on 213.207.104.11:
14:37:42.232694 IP 84.246.10.24.41053 > 213.207.104.20.80: S
557344343:557344343(0) win 5840 <mss 1460,sackOK,timestamp 218577173
0,nop,wscale 7>
14:37:42.232961 IP 84.246.10.24.41053 > 213.207.104.20.80: S
557344343:557344343(0) win 5840 <mss 1460,sackOK,timestamp 218577923
0,nop,wscale 7>
Mostly identical lines (and nothing else) keep appearing at a high rate,
even after I kill the connection on the client. Only after I remove the
service from LVS, this stops.
Any idea what may cause this? I'd be happy to provide additional
information, if needed.
Best regards,
Martijn Grendelman
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