Install htop on Sharc

[mikecroucher]

requested by @kuchenrolle

[willfurnass]

htop is awesome but as we don't allow normal users SSH to nodes its only of use to most folks if using a terminal multiplexer within an interactive session.

Perhaps what we really need is a web-based top-like interface running on each node. A web-based view on running and queuing jobs would also be nice. We'd need to consider what information we could and should expose via such interfaces though - we might want to use mod_auth_ldap to restrict access to just users with HPC accounts.

Also, depending on what @kuchenrolle wants htop for, qtop may be of (more?) use.

[kuchenrolle]

htop would be useful for monitoring CPU and memory usage when testing scripts before submitting them to the queue. qtop would then be great to monitor the whole cluster, but doesn't appear to provide easy per user per node information.

I find it easiest to work in the terminal, but a web-based interface sure makes most sense if most people can't actually ssh to sharc, though maybe it could just be both, given that I suppose the simplest way to do this would be to just pipe (part of) the q/htop output to the interface.

[drj11]

htop is useful when you have a multicore interactive session (or being nosey to see what memory hungry processes are sharing your node), or if you used -q to request a specific node on which you already have a running job [later edit: Hmm, maybe you can't do that second thing any more]