# Is cylc 8 able to interact with workflows launched on different hosts?

**URL:** <https://cylc.discourse.group/t/is-cylc-8-able-to-interact-with-workflows-launched-on-different-hosts/630>\
**Category:** Cylc Support\
**Created:** [April 11, 2023, 11:04pm UTC](https://cylc.discourse.group/t/is-cylc-8-able-to-interact-with-workflows-launched-on-different-hosts/630 "2023-04-11T23:04:42Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![jonnyhtw](https://yyz2.discourse-cdn.com/free1/user_avatar/cylc.discourse.group/jonnyhtw/32/232_2.png) [@jonnyhtw](https://cylc.discourse.group/u/jonnyhtw)\
**Post date:** [April 11, 2023, 11:04pm UTC](https://cylc.discourse.group/t/is-cylc-8-able-to-interact-with-workflows-launched-on-different-hosts/630/1 "2023-04-11T23:04:42Z")

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hi there,

i’m now able to use the `cylc` 8 gui on my personal laptop (mac) from home yay!

however, it looks like i can’t interact with it from another session on my work machine. for example, for the workflow `u-cv956/run1`, running on my work pc…

1. 

```auto
> cylc tui u-cv956/run1
[Errno -2] Name or service not known: 'maui02-eth5'

```

1. 

```auto
> cylc play u-cv956/run1
2023-04-11T22:46:26Z ERROR - Cannot determine whether workflow is running on maui02-eth5.
    /scale_wlg_persistent/filesets/opt_nesi/share/cylc/8.1.1/bin/python /opt/nesi/share/cylc/8.1.1/bin/cylc play --color=never --mode live
    u-cv956/run1
2023-04-11T22:46:26Z CRITICAL - Cannot tell if the workflow is running
    Note, Cylc 8 cannot restart Cylc 7 workflows.

```

1. 

screenshot when pressing the `play` button in the gui on my work machine

 ![Screenshot 2023-04-12 105056](https://global.discourse-cdn.com/free1/uploads/cylc1/original/1X/36e9ff72236124a46733b6f4d6dbe09a5072d15e.png)

is this the expected behaviour?

cheers,

jonny

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<div class="post-metadata">

**Author:** ![hilary.j.oliver](https://yyz2.discourse-cdn.com/free1/user_avatar/cylc.discourse.group/hilary.j.oliver/32/4_2.png) [@hilary.j.oliver](https://cylc.discourse.group/u/hilary.j.oliver)\
**Post date:** [April 11, 2023, 11:56pm UTC](https://cylc.discourse.group/t/is-cylc-8-able-to-interact-with-workflows-launched-on-different-hosts/630/2 "2023-04-11T23:56:39Z")

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Hi Jonny,

Cylc 8 can definitely interact with workflows running on different hosts.

I think what you mean here is “launched _from_ different hosts”. What’s happening, I think, is when you start a workflow from the web UI, for some reason an invalid host name gets recorded in the scheduler “contact file”, which means command line tools on the back end will try to contact the scheduler at an invalid address.

I’ll need to investigate this.

In the meantime, take a look at `~/cylc-run/<WORKFLOW_ID>/.service/contact`

It should contain (among other things) `CYLC_WORKFLOW_HOST=maui` (or possibly the fully qualified host name) but not `maui-eth5`. Try manually fixing the hostname in that file, it might restore access to the scheduler.

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<div class="post-metadata">

**Author:** ![hilary.j.oliver](https://yyz2.discourse-cdn.com/free1/user_avatar/cylc.discourse.group/hilary.j.oliver/32/4_2.png) [@hilary.j.oliver](https://cylc.discourse.group/u/hilary.j.oliver)\
**Post date:** [April 12, 2023, 1:02am UTC](https://cylc.discourse.group/t/is-cylc-8-able-to-interact-with-workflows-launched-on-different-hosts/630/3 "2023-04-12T01:02:57Z")

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Turns out this is a local networking issue - the node in question is self-identifying with a host name that’s not visible from other hosts.

I’ll contact @jonnyhtw via local channels…

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<div class="post-metadata">

**Author:** ![jonnyhtw](https://yyz2.discourse-cdn.com/free1/user_avatar/cylc.discourse.group/jonnyhtw/32/232_2.png) [@jonnyhtw](https://cylc.discourse.group/u/jonnyhtw)\
**Post date:** [April 12, 2023, 1:52am UTC](https://cylc.discourse.group/t/is-cylc-8-able-to-interact-with-workflows-launched-on-different-hosts/630/4 "2023-04-12T01:52:41Z")

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great thanks @hilary.j.oliver!