I am building a corosync/pacemaker/haproxy HA load balancer in Active/Active mode using ClusterIP. As this built on RHEL 6.5 I am restricted to using PCS to configure the LB.
One of the requirements is to maintain TCP state so that TCP based syslog audit is not lost during a fail over. I have two questions: 1) is it possible when using conntrackd to maintain TCP state to have a seamless transition to the remaining LB should one of the servers be shutdown. The work group in question cannot afford to loose any messages once the connection has commenced. Some machines will be using a reliable transmission method for syslog such as RELP but others will be using raw TCP. My testing shows that when sending a large of raw TCP messages via a single connection, the syslog server will loose messages when one of the LBs are shutdown or put into standby. The client machine will start ARPing for the mac address assigned to the VIP till a connection is established with the remaining LB. This can loose us up to 3 seconds worth of messages. In reality I don't expect such a large amount of traffic to be generated via a single connection. But the work group will not accept the solution if we loose any messages. Will this be a matter of managing the expectations of the work group, that during fail over, messages in transit will be lost when using raw TCP? 2) I have been looking for instructions to implement conntrackd as a resource using PCS in order to maintain TCP state and haven't had any luck. All instructions I have found implement conntrackd using cman. If anyone has an example for implementing conntrackd via pcs it would be much appreciated. -- Barry Banpen Fugyou - 10,000 Changes, No surprises ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. _______________________________________________ Linux-HA mailing list Linux-HA@lists.linux-ha.org http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
