On Wed, Aug 16, 2017 at 4:04 PM, Eric Dumazet <eric.duma...@gmail.com> wrote: > On Wed, 2017-08-16 at 10:18 +0530, Akshat Kakkar wrote: >> On Mon, Aug 14, 2017 at 2:37 PM, Akshat Kakkar <akshat.1...@gmail.com> wrote: >> > I have centos 7.3 (Kernel 3.10) running on a server with 128GB RAM and >> > 2 x 10 Core Xeon Processor. >> > I have hosted a webserver on it and enabled ssh for remote maintenance. >> > Previously it was running on Centos 6.3. >> > After upgrading to CentOS 7.3, occasionally (probably when number of >> > hits are more on the server), I am not able to create new connections >> > (neither on web nor on ssh). Existing connections keeps on running >> > fine. >> > >> > I did packet capturing using tcpdump to understand if its some >> > intermediate network issue. >> > What I found was the server is not replying for new SYN requests. >> > >> > So it's clear that its not at all application issue. Also, there are >> > no logs in applications logs for any connections dropped, if any. >> > >> > I check my firewall rules if there is some rate limiting imposed. >> > There is nothing in there. >> > >> > I check tc, if by mistake some rate limiting is imposed. There is >> > nothing in there too. >> > >> > I have increased noOfFiles to 1000000 and other sysctl parameters, but >> > the issue is still there. >> > >> > Has anybody experienced the same? >> > >> > How to go about? Anybody ... Please Help!!! >> >> Its getting lonely out here. Anybody there ??? > > We wont help you unless you use a recent kernel. > > 3.10 misses all recent improvements in TCP stack (4 years of hard work) > > > > >
I upgraded to 4.4 but still experiencing same issue. Please help.
