i am going to implement MAG to cluster, but link connect between them(MAG) is VPLS. i find in "cluster material of MAG" write:"Clustering is not supported across WANlinks". i confuse about it.So, Can i establish HA for MAG through VPLS ,yet?
MAG IC cluster is not supported across WAN links,
With VPLS enabled in your network I hope both the MAG devices will be seperated geographically and connected though VPLS link. This setup is also not officially supported by Juniper since cluster communication between nodes will be affected based on the network latency.
There might be no issues now however once you implement if there is a failover scenario the users who are newly connecting to the node which has become active might have issues in accessing resources protected behind firewall etc.
Hope my explanation clarifies your query
In a simpler way: it is not a supported scenario as it is not definitive that clustering can/cannot work depending upon latency.
From JTAC's past experience, we have seen heart-beat misses in these kind of scenarios.
We always recommend and support devices that are connected to same LAN segment.