Symptom
Intermittent VEM module flaps will be observed during switch over with SXPv1 peers.
Conditions
This is because of the SXP connections are initialized after HA switch over. Re-init is causing SXPv1 Speaker to terminate the connection with SXPv3 listener. Because connection is terminated, all SXP entries learnt from SXPv1 peer is getting purged. With 100+ modules, purge update is sent to all VEMs, since CTS uses unreliable MTS, some messages are getting dropped as there are too many messages that are generated between VSM and VEM. Because of the drop, VEM is requesting content refresh from VSM and that inturn causes VSM to queue lot of messages towards VEM and more drops. Because of this scenario, AIPC dropping Heart Beat messages between VSM/VEM. Heart beat lose is causing VEM to get detached and attached.
Workaround
It is recommended to have all SXPv3 speakers. V1 listeners are fine.
