[Paraview] Misleading facts about Catalyst

[Utkarsh Ayachit]

Kolja,

> Last week I asked how the server side can notify the client of recent
> changes. Utkarsh wrote this wouldn't be supported by Paraview. After I
> clarified that exactly this is happening during a Catalyst Live simulation,
> the discussion was mute. I am still hoping for an answer how to notify the
> client of any changes that might happen on the server side for example as a
> result of some network activity.

I've responded to the thread. Please note that Thursday-Sunday was a
holiday in the US, hence mailing list responses were expected to be
slow.

> Another example, some days before, I was wondering why Catalyst datasets of
> considerable size take so long from the Insitu side to the Live
> Visualization side, given that the Catalyst User Guide gives the impression
> that everything is designed for high throughput. Someone insisted that
> everything is transported through MPI until I mentioned that Paraview is not
> designed for a dynamically added MPI communicator. Only then it was
> explained that Catalyst data exchange is going through TCP...

While I am not sure which conversation you're referring to or whom you
were having that conversation, it's believable that there was
confusion between which data transfers you were referring to. All
communication between filters in a Catalyst in situ session is via
MPI. Only when you start doing "live" is when you encounter TCP. With
Live, currently the data transfer between the insitu ranks and the
"pvserver" ranks used for visualization is via TCP. Live support, in
my mind, is still in the early life cycle and needs more development
for production use.

> The Catalyst development seems increasingly problematic. Have the Catalyst
> developers left Kitware, or what is going on? We are trying to work on
> improved solutions, but with the recent quality of comments we can't see
> this happening.

Catalyst is indeed being actively developed and maintained. While we
try our best, responding to every mailing list inquiry can be quite
difficult. We do offer consulting services [1] if you want to work
Catalyst development team directly.

Hope that helps.

Utkarsh

[1] https://www.kitware.com/what-we-offer/#consulting