Download starts delayed

[Lite]

Hello
I hosted sites that have heavy traffic , this sites use more than 2TB bandwidth per day
Now i use trial 2-CPU LiteSpeed License

But a serious problem , sometimes server don't accept new connection or accept it late ,


Server information :
Processor 2 x E5620 2.40Ghz HT
Memory 24GB DDR3 ECC Memory
Hard Drive 4 x 2TB SAS 7,200 RPM
Raid H700 Raid Controller with BBU - Raid 10

IO wait :

root@ [~]# iostat -x
Linux 2.6.32-279.9.1.el6.x86_64 10/14/2012      _x86_64_        (16 CPU)

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.43    0.39    3.02    8.37    0.00   87.78

Device:         rrqm/s   wrqm/s     r/s     w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
sda             488.05    26.18  774.56    9.47 95965.97   280.25   122.76    43.33   55.26   1.18  92.19
sdb             381.67   160.30  653.17    5.51 81479.33  1325.98   125.71    32.48   49.32   1.24  81.84
dm-0              0.00     0.00    0.01    0.00     0.06     0.00     7.95     0.00   11.84   8.11   0.01
dm-1              0.00     0.00    0.42    0.79    18.94     6.33    20.86     0.05   42.67  15.56   1.88
dm-2              0.00     0.00    0.03    4.92     0.27    39.34     8.00     0.25   49.54  23.61  11.68
dm-3              0.00     0.00    0.02    0.00     1.26     0.01    67.89     0.00   44.77  26.06   0.05
dm-4              0.00     0.00    5.77   17.97   189.97   143.74    14.06     1.87   78.93   2.34   5.55
dm-5              0.00     0.00    0.53    7.54    10.74    60.31     8.80     1.13  139.75   3.04   2.45
dm-6              0.00     0.00 2315.83  169.42 177011.65  1355.38    71.77    22.24    8.92   0.40  99.30
dm-7              0.00     0.00    1.68    0.14   212.16     1.12   117.37     0.09   51.55  14.44   2.62

connection (Real time status) :

Http In	31KB	Http Out	103,030KB
Https In	0KB	Https Out	0KB
Max	122,880	Idle	86
Http Used	16,696	Http Free	106,184
Https Used	0	Https Free	40,960
In Processing	16,610	Req/Sec	62.1
Total Req	75,271	Total Cache Hits	0
Cache Hit Rate	0%	Cache Hits/Sec	0.0

Load is ok , i/o wait is ok , i think configuration is ok too
but i don't know why server don't accept new connection and this problem has caused connection time out or Download starts delayed

i attached number of connection screenshot and tuning configuration
please some one help me

 

[mistwang]

You need to check ip_conntrack limit, check output of 'dmesg', if the limit has been hit, you need to google it for solution.

Also, with your server, we recommend enabling "AIO" if you are serving tons of static files.

 

[NiteWave]

I noticed "Http Out: 103,030KB", this already reach or over the 1G bps NIC's capability. maybe a good example though: the bottle neck is at NIC, not litespeed or others.

 

[Lite]

I have 6 account on this server ( i use cPanel )
in account 1,2,4,5 download start fast
but in other account we get time out

what can i do ?

 

[Lite]

I'm really confused
download start in some account is very fast
but in some account is very late

The strange thing is , in accounts that have more connection than others , downloads start fast
!

 

[webizen]

is the download via php or direct static?

 

[Lite]

Hello
in all of them , download is directly

 

[Lite]

please help me
i also revive some emails like that

At [15/Oct/2012:17:00:22 +0100], web server with pid=17081 received unexpected signal=11, a core file is created. A new instance of web server will be started automatically!

Please forward the following debug information to bug@litespeedtech.com.
Environment:

Server: LiteSpeed/4.2 Enterprise
OS: Linux
Release: 2.6.32-279.9.1.el6.x86_64
Version: #1 SMP Tue Sep 25 21:43:11 UTC 2012
Machine: x86_64

If the call stack information does not show up here, please compress and forward the core file located in /tmp/lshttpd/.

[New Thread 17081]
[New Thread 17083]
[New Thread 17085]
[Thread debugging using libthread_db enabled]
Core was generated by `litespeed'.
Program terminated with signal 11, Segmentation fault.
#0  0x00000000004c6ab4 in HttpContext::getSecRuleSets (this=0x23ff310) at /home/gwang/release/httpd/httpd/http/httpcontext.h:516
        in /home/gwang/release/httpd/httpd/http/httpcontext.h
#0  0x00000000004c6ab4 in HttpContext::getSecRuleSets (this=0x23ff310) at /home/gwang/release/httpd/httpd/http/httpcontext.h:516
#1  0x00000000004bd48c in HttpConnection::processModSecRules (this=0x6ea6ec0, phase=32) at /home/gwang/release/httpd/httpd/http/httpconnection.cpp:202
#2  0x00000000004bd55d in HttpConnection::nextRequest (this=0x6ea6ec0) at /home/gwang/release/httpd/httpd/http/httpconnection.cpp:218
#3  0x00000000004c230b in HttpConnection::writeComplete (this=0x6ea6ec0) at /home/gwang/release/httpd/httpd/http/httpconnection.cpp:2161
#4  0x00000000004c23e3 in HttpConnection::doWrite (this=0x6ea6ec0, aioSent=0) at /home/gwang/release/httpd/httpd/http/httpconnection.cpp:2183
#5  0x00000000004c258d in HttpConnection::onWriteEx (this=0x6ea6ec0) at /home/gwang/release/httpd/httpd/http/httpconnection.cpp:2241
#6  0x000000000046bb2d in HttpIOLink::doWrite (this=0x6ea6ec0) at /home/gwang/release/httpd/httpd/http/httpiolink.h:162
#7  0x000000000046a544 in HttpIOLink::onWriteT (pThis=0x6ea6ec0) at /home/gwang/release/httpd/httpd/http/httpiolink.cpp:913
#8  0x0000000000468d13 in HttpIOLink::handleEvents (this=0x6ea6ec0, evt=4) at /home/gwang/release/httpd/httpd/http/httpiolink.cpp:180
#9  0x00000000005035a6 in epoll::waitAndProcessEvents (this=0x251f6c0, iTimeoutMilliSec=100) at /home/gwang/release/httpd/httpd/edio/epoll.cpp:333
#10 0x0000000000456d94 in EventDispatcher::run (this=0x23ccf98) at /home/gwang/release/httpd/httpd/http/eventdispatcher.cpp:225
#11 0x000000000041515d in HttpServerImpl::start (this=0x23ccf70) at /home/gwang/release/httpd/httpd/main/httpserver.cpp:473
#12 0x000000000041835b in HttpServer::start (this=0x8926f0) at /home/gwang/release/httpd/httpd/main/httpserver.cpp:1890
#13 0x000000000040eebb in LshttpdMain::main (this=0x23ccbb0, argc=1, argv=0x7fffe8646798) at /home/gwang/release/httpd/httpd/main/lshttpdmain.cpp:1840
#14 0x000000000040a63f in main (argc=1, argv=0x7fffe8646798) at /home/gwang/release/httpd/httpd/main.cpp:124