On 24/08/2013 9:45 p.m., x-man wrote:
Hi Amos, I have exactly the same issue as the above described. Running squid 3.3.8 in TPROXY mode. In my setup the squid is serving around 10000 online subscribers, and this problem happens when i put the whole HTTP traffic. If I'm redirecting only half of the users - then it works fine. I guess it's something related to LIMITS imposed by the OS or the Squid itself. Please help to identify the exact bottleneck if this issue, because this is scalability issue. squidclient mgr:info |grep HTTP HTTP/1.1 200 OK Number of HTTP requests received: 1454792 Average HTTP requests per minute since start: 116719.5
Nice. With stats like these would you mind supplying the data necessary for an entry in this page?
http://wiki.squid-cache.org/KnowledgeBase/Benchmarks (see section 2 for how to calculate the datum).
squidclient mgr:info |grep file Maximum number of file descriptors: 524288 Largest file desc currently in use: 132904 Number of file desc currently in use: 80893 Available number of file descriptors: 443395 Reserved number of file descriptors: 800 Store Disk files open: 0 ulimit -a from the OS core file size (blocks, -c) unlimited data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 386229 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1000000 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 386229 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited Some tunings applied also, but not helping much: echo "applying specific tunings" echo 500 65535 > /proc/sys/net/ipv4/ip_local_port_range echo 65000 > /proc/sys/net/ipv4/tcp_max_syn_backlog echo 600 > /proc/sys/net/ipv4/tcp_keepalive_time echo 50000 > /proc/sys/net/core/netdev_max_backlog echo 15 > /proc/sys/net/ipv4/tcp_keepalive_intvl echo 5 > /proc/sys/net/ipv4/tcp_keepalive_probes echo 1 > /proc/sys/net/ipv4/tcp_tw_reuse # it's ok echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle # it's ok echo 2000000 > /proc/sys/net/ipv4/tcp_max_tw_buckets #default 262144 on Ubuntu Let me know what other info might be useful for you?
Unfortunately all I can do is point you at the known reasons for the message. The things to figure out is whether there is some limit in TPROXY kernel code itself (the socket match module is the critical point I think) about how many sockets it can manage. Or if some of the traffic is coming an excessive amounts from any particular IPs and reducing the amount of outgoing connections that can be used for it.
Amos
