The graphs of version 2 workunits, will not be readable by old builds.

That is, any workunits created by eclccserver/eclserver from a build that contains this patch, will not be seen by older hthor/roxie/thor/esp's.

I *think* though, that no old hthor/roxie/thor/eclserver/eclccserver should get to look at a new workunit. IOW, all these components which are associated with a eclccserver should be on a the same build.
Different clusters, may be on different builds and together have their hthor/thor/eclserver on that same build etc.

However, in such mixed environments, esp's should be in sync with the most current, otherwise they will not be able to read the new workunits.