Messages in this thread |  | | From | gphat@cafes ... | Subject | Large numbers of TCP resets | Date | Wed, 3 Jul 2002 20:15:53 GMT |
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Recently, the web-app at the company I work for started having problems load balancing. This was traced back to a large number of tcp-resets being sent from the web servers to the clients.
Here's netstat output for one of the boxen: 437761 active connections openings 0 passive connection openings 21 failed connection attempts 0 connection resets received 101 connections established 140497907 segments received 149967684 segments send out 116610 segments retransmited 111 bad segments received. 1003306 resets sent
This box is running an apache/tomcat/jboss setup serving both HTTP and RMI requests. The reset packets disrupt the load balancing method, as the load balancers think the reset means the connection can now be round-robined to the next machine. This can be masked by using cookie-based balancing, but I am worried that we would be masking a problem.
Documentation concerning tuning buffers for network purposes say that 2.4 is good at auto-tuning, and that only /proc/sys/net/ipv4/tcp_wmem|tcp_rmem might need tweaking.
The kernel is 2.4.9-31smp from RedHat 7.2. The cards are Intel 82557's. There are two interfaces, with 1 for client access and 1 used for communication with the backend database. (The ->client is the one we are worried about).
Any ideas on why the interfaces would be doing this? The boxes served 1.6 hits/sec average over last month for a total of about 10Gb. Is there some tuning that needs to take place?
Thanks in advance.
Cory 'G' Watson
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