On one of the flume server I see a great loss of UDP packets at rush hour. DNS server logs collected in syslog format on this server. 13% receive errors. "netstat -us". OS - centos 6.6, kernel 2.6.32-504.el6.x86_64, 4G RAM, 2CPU(s) load average 0-2, charge memory - 60% max, load network - 70% max. I made to optimize the kernel sysctl.conf net.core.rmem_max net.core.netdev_max_backlog net.ipv4.udp_rmem_min net.ipv4.udp_wmem_min these paramters are maximized but % of "udp receive errors" does not change.
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