Hi folks, I'm worried. I'm in a situation where I've put a proxy cluster into production without adequately testing the Zorp component under load. I spent a lot of time testing load balancing, but didn't check that Zorp could cope with a large number of concurrent connections. We're running zorp-2.1.5.5 on a Linux 2.4.25 (Gentoo) kernel with glibc-2.3.2 (Gentoo r9). The http proxy dies with sig11 (all registers printed zero in the stack dump sent to syslog) when it reaches some small number of concurrent threads over 130. So we tried using just the TCP plug proxy, even for HTTP connections, but can't get a single instance using more than 1020 threads. We have 4 zorp boxes handling a 100Mbps uplink, load-balanced with LVS. LVS ipvsadm also shows that the Zorp boxes aren't handling more than about 1000 concurrent connections. The visible symptom of all this is that some connection attempts aren't even accepted, while others are accepted but not serviced. I've done a lot of Googling, and all the stuff on how to increase the number of processes allowed per process doesn't seem to apply; PTHREAD_THREADS_MAX is already large in the glibc sources, and NR_TASKS doesn't exist in the kernel source. I've bumped up ulimits for file descriptors and processes per user, but these don't help. Help. I realise I went into production prematurely, but now that I'm here, it's a horrible place and I'm worried that I overestimated Zorp's ability to cope with load. Am I expecting too much from Zorp, or is this just something that more experienced Linux folks would know about? Any ideas on how to get Zorp to handle the kind of concurrency other people on the list must be getting[1] would be greatly appreciated. Either I need to get Zorp to service a larger number of concurrent requests, or I need to know why it's not coping when it reaches the limit on concurrent requests. I tried lowering --threads to 200, but my connection attempts still either aren't accepted or time out waiting for a response. Thanks, Sheldon. [1] I base this assumption on a posting in the archives, where the poster said he needed about 4 zorp proxy hosts to handle 100Mbps.