Shulou(Shulou.com)06/02 Report--

Linux system log reports how to solve the "Time wait bucket table overflow" error. I believe many inexperienced people don't know what to do about it. Therefore, this paper summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

Problem phenomenon

The Linux Syslog / var/log/messages is full of error messages similar to "kernel: TCP: time wait bucket table overflow", prompting "time wait bucket table" overflow, and the system displays something like the following.

Feb 18 12:28:38 iMub / kernel: TCP: time wait bucket table overflowFeb 18 12:28:44 iMub / / * kernel: printk: 227messages suppressed.Feb 18 12:28:44 iMub / / * kernel: TCP: time wait bucket table overflowFeb 18 12:28:52 iMub / / * kernel: printk: 121messages suppressed.Feb 18 12:28:52 iMub / time wait bucket table overflowFeb * kernel: TCP: time wait bucket table overflowFeb 18 12:28:53 iMube / kernel: printk: 351 messages suppressed. Feb 18 12:28:53 iMurphy * kernel: TCP: time wait bucket table overflowFeb 18 12:28:59 iMurphy * kernel: printk: 319 messages suppressed.

Execute the following command to count the number of TCP connections in the TIME_WAIT state and find that there are a large number of TCP connections in the TIME_WAIT state.

Netstat-ant | grep TIME_WAIT | wc-l cause analysis

The parameter net.ipv4.tcp_max_tw_buckets adjusts the number of managed TIME_WAIT states in the kernel. When the instance is in TIME_WAIT state and the sum of connections that need to be converted to TIME_WAIT state exceeds the net.ipv4.tcp_max_tw_buckets parameter value, a "time wait bucket table" error is reported in the messages log, and the kernel closes some TCP connections that exceed the parameter value. You need to increase the net.ipv4.tcp_max_tw_buckets parameters according to the actual situation, and at the same time improve the TCP connection at the business level.

Solution method

Execute the following command to count the number of TCP connections.

Netstat-anp | grep tcp | wc-l

Execute the following command to query the net.ipv4.tcp_max_tw_buckets parameter. If you confirm that the connection is highly used, it is easy to exceed the limit.

Vi / etc/sysctl.conf

According to the situation of the site, increase the value of net.ipv4.tcp_max_tw_buckets parameters.

Execute the sysctl-p command to make the configuration effective.

After reading the above, have you mastered how to solve the "Time wait bucket table overflow" error in the Linux system log? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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