# Connect to an already running simulation
**URL:** https://discourse.paraview.org/t/connect-to-an-already-running-simulation/11207
**Category:** In Situ Support
**Tags:** catalyst
**Created:** [January 19, 2023, 1:54pm UTC](https://discourse.paraview.org/t/connect-to-an-already-running-simulation/11207 "2023-01-19T13:54:38Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@CsatiZoltan](https://discourse.paraview.org/u/CsatiZoltan)
#### Post date: [January 19, 2023, 1:54pm UTC](https://discourse.paraview.org/t/connect-to-an-already-running-simulation/11207/1 "2023-01-19T13:54:39Z")
Imagine the following use case.
Sets of ParaView servers and a massive simulation are launched as a job on multiple nodes of a cluster. It is not known in advance when the job scheduler allows the job to start running. Next day, we see that the simulation has started at night, so we want to look into its current state. Therefore, we launch the ParaView GUI, connect to the ParaView server, and start Catalyst.
My experience is that the simulation can only be suspended with Catalyst if it is already listening to it. Once the simulation has started, we cannot establish a connection with it. Am I right? Is there a way to intercept a running simulation with Live Visualization mode enabled?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 19, 2023, 2:04pm UTC](https://discourse.paraview.org/t/connect-to-an-already-running-simulation/11207/2 "2023-01-19T14:04:09Z")
@nicolas.vuaille @Francois_Mazen