Hi Folks,
I just found this thread in the archives describing my problem.
So let me tune in so we hopefully can find that bummer.
Symptoms:
I'm also suffering from very slow connections via the VIPs in contrast
to accessing the real servers directly. A wget fetch from a particular
web takes ~40sec via the VIP and ~4sec directly.
Analysis:
Looking at the related tcpdumps for the VIP traffic I see:
in dump (Client<->Director):
* TCP Retransmissions VIP->Client
* Duplicate ACKs Client->VIP
in dump (Director<->Realserver)
* TCP Retransmissions Realserver->Client
* Duplicate ACKs Client->Realserver
* TCP previous segment lost Client->Realserver (appears after each Dup ACK)
Note: Routing client traffic directly to the real server shows perfect
TCP traffic!
Environment:
The director is acting as firewall, router, loadbalancer using
ipvsadm v1.24 2003/06/07 (compiled with popt and IPVS v1.2.0)
and configured as LVS-NAT to access the real servers.
Kernel tested: 2.6.16, 2.6.18, 2.6.22 - no difference noticable
Hardware issues can be ruled out as the directly routed traffic uses
exact the same path.
Any hints welcome!
Regards,
Joerg
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