On a single Zimbra 5.0.x server, how many simultaneous instances of the following processes should there be please?

java
mysqld
mysqld_safe

We are working with one set of Zimbra servers where there is one of each, and on another system there are normally two of each, with sometimes three java processes running at the same time.

We'd like to configure monitoring not only to watch out for zombie processes, but also to make sure processes that restart themselves (e.g. MySQL) complete the restart successfully.

Thanks,
Mark