06-20-2014 09:29 AM
I have a cluster of 4 SteelApp Traffic Managers that has always been using multicast communication for heartbeats between TMs.
I want to do big network changes that will make multicast temporarily unavailable. Because of this, I plan to fully switch the cluster to unicast communication. At least for the time of the network migration.
How does a cluster behave if you switch it to unicast? In case of failure I am mainly worried about a TM unable to communicate with the others, trying to grab all traffic group IP addresses.
Is there a way to do this change safely? Maybe disabling temporarily fault tolerance?
Solved! Go to Solution.
06-22-2014 07:33 AM
There shouldn't be any problems. A TCPDUMP on my system during a multicast to unicast conversion, it just keeps ticking. So long as the STM's can see each other and can communicate via UDP 9090, you should be good.
root@i-stm001:~# tcpdump -ni any udp port 9090
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on any, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes
00:17:47.173873 IP 184.108.40.206.39086 > 220.127.116.11.9090: UDP, length 70
00:17:47.461110 IP 18.104.22.168.59784 > 22.214.171.124.9090: UDP, length 70
00:17:47.469244 IP 126.96.36.199.35666 > 188.8.131.52.9090: UDP, length 70
00:17:47.969215 IP 184.108.40.206.60123 > 220.127.116.11.9090: UDP, length 70
00:17:48.460930 IP 18.104.22.168.39856 > 22.214.171.124.9090: UDP, length 70
00:17:48.470873 IP 126.96.36.199.60123 > 188.8.131.52.9090: UDP, length 70
Per the documentation though, make sure you have a non zero value for the "state_sync_time" setting: