Hi All,
We have been investigating an issue with reduced throughput. (its quite
possible that its nothing to do with HAProxy.)
I thought I would just check here to see if this rings a bell with anyone.
We are currently looking to update our kernel from 3.10.18 to 4.4.49. It
appears that in the move from 3.x.x to 4.x.x at some point the kernel devs
change the tcp_mem calculation which results in halving the values based on
the same amount of RAM. Although that isnt the problem it just highlighted
it.
Our test setup is
Mutiple Clients --> Haproxy --> Real Server.
If I run a fairly heavy load using iperf through haproxy using the 3.10.18
kernel and I check -
cat proc/net/sockstat
sockets: used 193
TCP: inuse 116 orphan 0 tw 17 alloc 118 mem 25591
UDP: inuse 12 mem 3
UDPLITE: inuse 0
RAW: inuse 1
FRAG: inuse 0 memory 0
cat /proc/sys/net/ipv4/tcp_mem
89544 119392 179088
When I reboot into the 4.4.49 kernel and run the same test I get -
cat proc/net/sockstat
sockets: used 198
TCP: inuse 115 orphan 0 tw 18 alloc 117 mem 43957
UDP: inuse 12 mem 2
UDPLITE: inuse 0
RAW: inuse 1
FRAG: inuse 0 memory 0
cat /proc/sys/net/ipv4/tcp_mem
44721 59631 89442
Haproxy ------
Build options :
TARGET = linux2628
CPU = generic
CC = gcc
CFLAGS = -m64 -march=x86-64 -O2 -g -fno-strict-aliasing
-Wdeclaration-after-statement -fwrapv
OPTIONS = USE_ZLIB=1 USE_REGPARM=1 USE_OPENSSL=1 USE_STATIC_PCRE=1
Default settings :
maxconn = 2000, bufsize = 16384, maxrewrite = 1024, maxpollevents = 200
Encrypted password support via crypt(3): yes
Built with zlib version : 1.2.3
Running on zlib version : 1.2.3
Compression algorithms supported : identity("identity"),
deflate("deflate"), raw-deflate("deflate"), gzip("gzip")
Built with OpenSSL version : OpenSSL 1.0.2j-fips 26 Sep 2016
Running on OpenSSL version : OpenSSL 1.0.2j-fips 26 Sep 2016
OpenSSL library supports TLS extensions : yes
OpenSSL library supports SNI : yes
OpenSSL library supports prefer-server-ciphers : yes
Built with PCRE version : 7.8 2008-09-05
Running on PCRE version : 7.8 2008-09-05
PCRE library supports JIT : no (USE_PCRE_JIT not set)
Built without Lua support
Built with transparent proxy support using: IP_TRANSPARENT IPV6_TRANSPARENT
IP_FREEBIND
Available polling systems :
epoll : pref=300, test result OK
poll : pref=200, test result OK
select : pref=150, test result OK
Total: 3 (3 usable), will use epoll.
Available filters :
[SPOE] spoe
[TRACE] trace
[COMP] compression
Ive tried 4.4.95 kernel and get the same result Ive also tried the 4.9.59.
Ive tried the latest 1.7.9 HAProxy too.
Does anyone have any ideas?
Thanks
--
Mark Brookes
Loadbalancer.org Ltd.
www.loadbalancer.org
+44 (0)330 380 1064
m...@loadbalancer.org
