[squid-users] how to achieve squid to handle 2000 concurrent connections?

Sun Apr 19 09:58:34 UTC 2015

Hello,

I’ve got the following setup, each application on its own virtual machine:

Client (sends http-requests to proxy)—> Squid (sends http-requests to apache based on destination IP and round robin to multiple apache machines) —> Apache (setting up a two way ssl to the requested server) —> HTTPS-server

This setup works great, and I have the Apache and the HTTPS-server its performance tuned. Both can handle 2000 concurrent connections of file sizes up to 10MB.

Unfortunately I haven’t been successful with the Squid-server. After a while I’m getting the following error messages in the log:
1429432828.200  62854 10.10.7.16 TCP_MISS_ABORTED/000 0 GET http://https.example.com/index.html - ROUNDROBIN_PARENT/192.168.0.20 -

The Squid virtual machine contains the following:
CentOS 7.1 with latest updates
Squid Cache: Version 3.3.8
CPU: Intel Xeon E312xx (Sandy Bridge) - 1799.998 MHz (4 cores)
Memory: 4096 MiB
Harddisk: 10 GiB, SCSI, raw, cache none

When I execute a performance test with 2000 concurrent connections handling a file size of 10KB on each request.
# ab -n 10000 -c 2000 -X 10.10.7.15:3128 http://https.example.com/index.html
This is ApacheBench, Version 2.3 <$Revision: 1430300 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking https.rinis.nl [through 10.10.7.15:3128] (be patient)
Completed 1000 requests
Completed 2000 requests
Completed 3000 requests
Completed 4000 requests
Completed 5000 requests
Completed 6000 requests
Completed 7000 requests
Completed 8000 requests
apr_pollset_poll: The timeout specified has expired (70007)
Total of 8610 requests completed

I have the command "vmstat 5” running on the squid server:
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 2  0      0 3823916    764 124992    0    0   519    26  237  503  2  3 92  3  0
 0  0      0 3823744    764 125072    0    0     0     0   44   79  0  0 100  0  0
 0  0      0 3823776    764 125044    0    0     0     2   39   70  0  0 100  0  0
 0  0      0 3729540    764 139116    0    0     1     0 2145  257  1  2 97  0  0
 0  0      0 3728432    764 139888    0    0     0    46 2297  594  1  1 97  0  0
 0  0      0 3726484    764 140892    0    0     0    39 2869  581  2  1 97  0  0
 0  0      0 3725528    764 141376    0    0     0     0 2843  648  2  2 96  0  0
 0  0      0 3724980    764 142008    0    0     0    69 2824  529  2  1 97  0  0
 0  0      0 3724584    764 142540    0    0     0     0 2742  472  2  1 97  0  0
 0  0      0 3723696    764 143004    0    0     0     0 2511  577  2  1 97  0  0
 0  0      0 3722840    764 143200    0    0     0    12  884  228  1  1 99  0  0
 0  0      0 3722704    764 142900    0    0     0     0  136  127  0  0 100  0  0
 0  0      0 3722504    764 142744    0    0     0     0   40   70  0  0 100  0  0
 0  0      0 3722456    764 142784    0    0     0   114   37   68  0  0 100  0  0
 0  0      0 3722208    764 142832    0    0     0     0   41   68  0  0 100  0  0
 0  0      0 3722480    764 142280    0    0     0     0  179   82  0  0 100  0  0
 0  0      0 3722544    764 142140    0    0     0     7   41   75  0  0 100  0  0
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 1  0      0 3722544    764 142136    0    0     0     0   36   67  0  0 100  0  0
 0  0      0 3722996    764 141552    0    0     0     0   42   75  0  0 100  0  0
 0  0      0 3722980    764 141568    0    0     0     0   37   68  0  0 100  0  0
 0  0      0 3723028    764 141524    0    0     0     0   36   66  0  0 100  0  0
 0  0      0 3736816    764 130352    0    0     0     0  809  114  0  0 99  0  0
 0  0      0 3737544    764 130268    0    0     0    41   42   74  0  0 100  0  0

It looks like the hardware has enough resources during the benchmark test.

I’ve got the following squid.conf running:
cache_peer 192.168.0.18 parent 3128 0 round-robin no-query no-digest
cache_peer 192.168.0.20 parent 3128 0 round-robin no-query no-digest

acl development_net dst 192.168.0.0/24
cache_peer_access 192.168.0.18 allow development_net
cache_peer_access 192.168.0.20 allow development_net

never_direct allow all
cache deny all

maximum_object_size_in_memory 16 MB
cache_mem 2048 MB

The squid must not cache at all.

Any help is welcome.

Abdelouahed
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squid-cache.org/pipermail/squid-users/attachments/20150419/06c8f281/attachment.html>