Is it bad practice to run gh-ost on a replica?

Hi,

I was having this discussion with someone from our SRE team who believe gh-ost should not be running on one of the replicas in our mysql cluster. But after searching around I couldn't find any explicit guidance on that.

I thought running gh-ost on the replica that's also generating the RBR replication log that gh-ost is tracking would skip a network hop and get the replication data to the gh-ost even faster. Further more, this is a replica that's not taking production traffic normally (it's our fallback read-only replica).

Is there any additional requirement we should know about to decide whether to run gh-ost on a replica or not other than the common-sense load/resource sharing considerations?

Thanks for open-sourcing gh-ost. We've been liking the tool a lot! :-)