# Issue with solver dummy

**URL:** <https://precice.discourse.group/t/issue-with-solver-dummy/1259>\
**Category:** Official adapters and tutorials\
**Tags:** mpi\
**Created:** [December 21, 2022, 8:15pm UTC](https://precice.discourse.group/t/issue-with-solver-dummy/1259 "2022-12-21T20:15:45Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![nish-ant](https://avatars.discourse-cdn.com/v4/letter/n/ad7895/32.png) [@nish-ant](https://precice.discourse.group/u/nish-ant)\
**Post date:** [December 21, 2022, 8:15pm UTC](https://precice.discourse.group/t/issue-with-solver-dummy/1259/1 "2022-12-21T20:15:45Z")

</div>

I am trying to execute a [solver dummy](https://github.com/ajaust/precice-parallel-solverdummies) which runs in serial configuration:

```plaintext
python3 ./solverdummy-python-parallel.py ../precice-config-parallel.xml SolverOne &> log.runOne &
python3 ./solverdummy-python-parallel.py ../precice-config-parallel.xml SolverTwo &> log.runTwo &

```

but gets stuck while running in parallel in [partitioned configuration](https://precice.org/running-slurm.html#running-partitioned-simulations):

```plaintext
mpirun -n 2 -hostfile hosts.SolverOne python3 ./solverdummy-python-parallel.py ../precice-config-parallel.xml SolverOne &> log.runOne &
mpirun -n 2 -hostfile hosts.SolverTwo python3 ./solverdummy-python-parallel.py ../precice-config-parallel.xml SolverTwo &> log.runTwo &

```

Both `log.runOne` and `log.runTwo` show the same stage at which the simulation is stuck:

```plaintext
preCICE:^[[0m This is preCICE version 2.4.0
preCICE:^[[0m Revision info: no-info [Git failed/Not a repository]
preCICE:^[[0m Build type: Release (without debug log)
preCICE:^[[0m Configuring preCICE with configuration "../precice-config-parallel.xml"
preCICE:^[[0m I am participant "SolverOne"
preCICE:^[[0m Setting up primary communication to coupling partner/s

```

System info:

- OS: CentOS Linux release 7.9.2009 (Core)
- preCICE version: [2.4.0](https://github.com/precice/precice/releases/tag/v2.4.0)
- Open MPI version: 4.1.3

How can I resolve this issue? Please let me know if more information is needed.

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<div class="post-metadata">

**Author:** ![Makis](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/makis/32/25_2.png) [@Makis](https://precice.discourse.group/u/Makis)\
**Post date:** [December 22, 2022, 7:00am UTC](https://precice.discourse.group/t/issue-with-solver-dummy/1259/2 "2022-12-22T07:00:05Z")

</div>

Does any of these hints help? [Help! The participants are not finding each other! - #2 by Makis](https://precice.discourse.group/t/help-the-participants-are-not-finding-each-other/646/2)

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<div class="post-metadata">

**Author:** ![nish-ant](https://avatars.discourse-cdn.com/v4/letter/n/ad7895/32.png) [@nish-ant](https://precice.discourse.group/u/nish-ant)\
**Post date:** [January 4, 2023, 9:26am UTC](https://precice.discourse.group/t/issue-with-solver-dummy/1259/3 "2023-01-04T09:26:06Z")

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Hello @Makis. The solver dummy is now running. I’m not sure what exactly fixed it but I did the following changes:

1. Installed the python package `mpi4py` in the working environment and using it instead of the same package available as a module on the cluster.

2. Included the network interface in the configuration file:

```plaintext
<m2n:sockets from="SolverOne" to="SolverTwo" exchange-directory="../" network="ib0" />

```

Thanks for the help!

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<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/precice/original/1X/67d2a5fa6f80e597e2267ff17fa8c1673cd11caa.svg) [@system](https://precice.discourse.group/u/system)\
**Post date:** [January 7, 2023, 9:26am UTC](https://precice.discourse.group/t/issue-with-solver-dummy/1259/4 "2023-01-07T09:26:56Z")

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