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items: kernel: TCP: time wait bucket table overflow

kernel: TCP: time wait bucket table overflow
type: item
description: Hi! After updating to test018 OpenVZ patch my syslog full of those messages. /proc/user_beancounters shows nothing unusual comparing with previous kernel. Various docs says that this message indicates low memory situation or simple DoS attack and consider increase net.ipv4.tcp_max_tw_buckets but it didn't help. I'm found another sysctl - net.ipv4.tcp_max_tw_buckets_ub, but it undocumentend in ovz docs and looking in code shows that it's internal switch for ubc counters. So what I can do now and how ovz kernel affects this? :) Okay, it's heavy loaded system with 2 Gigs of RAM/1.4 P4 CPU and 1x100Mbit e100 NIC. According nginx internal status there is not so many connections: Active connections: 1067 server accepts handled requests 6494 6494 9525 Reading: 1 Writing: 6 Waiting: 1060 ~# uptime 23:36:22 up 2 days, 10:25, 1 user, load average: 0.80, 2.06, 2.51 ~# free total used free shared buffers cached Mem: 2072844 1825712 247132 0 128736 951484 -/+ buffers/cache: 745492 1327352 Swap: 995896 3780 992116 PS I can attach kernel buildconfig and dmesg if needed. -- WBR et al.
creator: lakostis
date: 2006-10-02T19:42:29-00:00