[CentOS] Memcache timeouts?

[Rafał Radecki]

No, the php scripts are executed from crontab.

2013/3/22 Leon Fauster <leonfauster at googlemail.com>:
> Am 22.03.2013 um 15:37 schrieb Rafał Radecki <radecki.rafal at gmail.com>:
>> Hi All.
>>
>> I am currently using memcache daemon in version 1.4.15 on one of my
>> servers. The second one is executing php scripts which use mentioned
>> memcache daemon (php53-pecl-memcache-2.2.5).
>>
>> Memcache server:
>> CentOS release 6.3 (Final)
>> 2.6.32-279.5.2.el6.centos.plus.x86_64
>> uptime 184 days
>>
>> PHP server:
>> CentOS release 6.3 (Final)
>> 2.6.32-279.19.1.el6.centos.plus.x86_64
>> uptime 43 days
>>
>> The memcache server gets about:
>> - 250Mb/s traffic
>> - 4500 connections/s
>>
>> On PHP server I get sometimes timeouts, ~20-30 daily. Both servers are
>> not swapping, they have free memory, cpu is ~40% used max. But I have
>> found some errors in netstat -s:
>>
>> Memcache server:
>> TCP
>> 7251 failed connection attempts (incrementing)
>> 56447 connection resets received (incrementing)
>> TcpExt
>> 36 packets pruned from receive queue because of socket buffer overrun
>> (not incrementing)
>> 2820 packets collapsed in receive queue due to low socket buffer (not
>> incrementing)
>> 459479 connections reset due to unexpected data (incrementing)
>>
>> PHP server:
>> TCP
>> 540 failed connection attempts (incrementing)
>> 381066 connection resets received (incrementing)
>> TcpExt
>> 7194 packets pruned from receive queue because of socket buffer
>> overrun (incrementing)
>> 250104 packets collapsed in receive queue due to low socket buffer
>> (incrementing)
>> 2447931 connections reset due to unexpected data (incrementing)
>>
>> I have tuned tcp/ip a bit:
>>
>> net.ipv4.tcp_fin_timeout = 5
>> net.ipv4.tcp_tw_reuse = 1
>> net.core.somaxconn = 1024
>> net.ipv4.tcp_max_syn_backlog = 4196
>> net.core.netdev_max_backlog = 4196
>> net.ipv4.tcp_sack = 0
>> net.ipv4.ip_local_port_range = 8192 65534
>>
>> net.core.rmem_max = 8388608
>> net.core.wmem_max = 8388608
>> net.ipv4.tcp_rmem = 4096 65536 8388608
>> net.ipv4.tcp_wmem = 4096 65536 8388608
>>
>> and set txqueuelen for interfaces (1Gb/s) to 5000.
>>
>> but where to look next? May it be so that the php client version is
>> buggy? Any other tips?
>
>
>
> just supposing - are you using httpd? -> listenbacklog
>
> --
> LF
>
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