[squid-users] Urgent Help Needed :Two Squid Servers performance issue when working with NAT

Hey ,Guys

We met a performance issue when Squid working with NAT ...
Thanks in advance for your attention.

There are two squid servers, Squid1 and Squid 2.
And We use web polygraph to do the performance test. So there are
another two servers, PolyClient and PolyServer.
Firstly, the 4 servers were in the same vlan. We used PolyClient to
send traffic to both Squid1 and Squid2. And the PolyServer could
receive all http requests. All in a word, every server worked well.
Secondly, we chaged the deployment. PolyClient, squid1 and Squid2 were
put into the internal vlan. PolyServer was put into another external
vlan. In this situation, PolyClient, Squid1 and Squid2 can not reach
PolyServer directly. So we add a NAT functionality which provide the
NAT in a PC between the squid server and Polyserver .
.
We send traffics to only one squid server. All is OK. But if we sent
the traffics to the two squid servers in the same time.
Some error occurred. , which come from squid1. But on the squid2 side,
all is OK.
part of netstat -na in squid2 output like following:
tcp 0 1 198.18.24.3:46304 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46311 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46310 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46309 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46308 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46331 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46330 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46329 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46328 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46335 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46334 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46333 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46332 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46323 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46322 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46321 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46320 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46327 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46326 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46325 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46324 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46283 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46282 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46281 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46280 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46329 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46328 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46335 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46334 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46333 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46332 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46323 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46285 10.56.233.99:9999
     SYN_SENT
tcp 0 1 198.18.24.3:46284 10.56.233.99:9999
     SYN_SENT
..
tcp 0 0 198.18.24.3:9001 198.18.255.1:33454
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:34222
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:34478
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:35758
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:34990
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:35246
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:36526
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:37294
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:38830
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:38062
    ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:39342
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:39598
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:40878
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:40110
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:41902
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:41390
     ESTABLISHED
tcp 0 0 198.18.24.3:9001 198.18.255.1:42926
     ESTABLISHED
.....
We check the connections on squid1,
[root_at_squid1 ~]# cat /proc/net/sockstat
sockets: used 40107
TCP: inuse 40020 orphan 0 tw 3 alloc 40028 mem 20034
UDP: inuse 18
RAW: inuse 0
FRAG: inuse 0 memory 0
Then We did the functional test in the same enviorment :
We found out Squid 1( 198.18.24.3 ) has sent lots of SYN_SENT to
Polyserver (10.56.233.99) to try to estiblish TCP , but no response
from polyserver side , so the squid1 to webpolygraph client
(198.18.255.1) have to keep the TCP connection . all these connection
make the squid1 server keep lots of TCP connection. (Very abnormal
state)
Looking forward your suggestion .
Thanks,
-Arkin
Received on Thu Jul 24 2008 - 14:20:54 MDT