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Hello,
Despite the fact you seem to have solved the problem (reading the rest
of the thread) I believe that the problem has a different nature.
I've been trying to set up an LVS-DR director for Windows NT IIS https load
balancing.
What are the keepalive settings of your IIS thread when forked of generally?
I have the wlc load balancing algo with a 3600 seconds of persistance (I
need this high persistance due to stupid session stuff).
This is really stupid if I can second you because NT doesn't handle a
lot of long sessions very well. See below ...
The problem I have is that once we start using it people start to get quite
random connection timeouts. Checking with ipvsadm -L -c -n I noticed these
connections hang on SYN_RECV state.
They don't hang on the director, the NT machine is just too slow or your
application is broken.
I have set up Windows NT with the MS Loopback Adapter, and this works great
(at first sight). The problem was mostly reported by customers having high
bandtwidth connections (cable & DSL).
?? Strange.
On some 1500 connections I had about 10% in SYN_RECV state. This made the
site randomly unavailable for the customers.
Because the IIS on your NT server couldn't handle the concurrent
sessions anymore. I bet you 5 bucks on it.
I have a setup balancing 2 FreeBSD machines using the same setup and I have
never seen these 'SYN_RECV' states on that setup.
Also https? The same setup, same application?
What could this mean? Is the use Windows NT the problem (problems using
their TCP/IP stack), or have I misconfigured my LVS (connection hash table
too small, missed out some timeouts, persisteny too long... Etc..)
What is the SP release?
The Windows NT machines are NT4 and working without problem connecting
directly to them.
Maybe you have a configuration problem on the IIS, something like too
little settings for max concurrent sessions or keepalive quirks.
What does this SYN_RECV mean anyway, and how comes there are so many on that
setup???
SYN_RECV means exactly what it tries to tell you: The director has
received the SYN as the first part of the 3-way handshaking and has
forwarded the packet to the real server. He won't see the the SYN_ACK in
LVS_DR mode so it's very important that you have the timings correct and
that the realserver really replies to requests.
Since you state that basically it works to a certain extent and starting
from there you experience problems I'm really inclined of thinking that
either the application is broken, ISS is misconfigured or you haven't
patched your NT to SP6.
Thanks for every help I can get !
Hope I wasn't too arrogant. I wish you good luck,
Roberto Nibali, ratz
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