# Addprocs(\["ip.ip.ip.ip"\], ...) hangs on Windows, works on Linux VM on same machine

**URL:** <https://discourse.julialang.org/t/addprocs-ip-ip-ip-ip-hangs-on-windows-works-on-linux-vm-on-same-machine/71659>\
**Category:** General Usage\
**Tags:** distributed\
**Created:** [November 17, 2021, 1:31pm UTC](https://discourse.julialang.org/t/addprocs-ip-ip-ip-ip-hangs-on-windows-works-on-linux-vm-on-same-machine/71659 "2021-11-17T13:31:19Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![lawless-m](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/lawless-m/32/30869_2.png) [@lawless-m](https://discourse.julialang.org/u/lawless-m)\
**Post date:** [November 17, 2021, 1:31pm UTC](https://discourse.julialang.org/t/addprocs-ip-ip-ip-ip-hangs-on-windows-works-on-linux-vm-on-same-machine/71659/1 "2021-11-17T13:31:19Z")

</div>

I have 3 Julia instances, Windows, Linux in a QEMU VM on the same machine and remote Linux.

I mention the Remote / VM thing to eliminate network issues.  
The same happens from the Windows machine _to_ the VM.

Julia on Windows connects, authenticates (twice) and then hangs

In the QEMU to the remote machine

```julia
julia> addprocs([Rlinux], tunnel=true)
2-element Vector{Int64}:
 3
 4
julia> @everywhere addxy(x, y) = x + y
julia> @everywhere curry(f, y) = x->f(x, y)
julia> pmap(curry(addxy, 15), 1:5)
5-element Vector{Int64}:
 16
 17
 18
 19
 20

```

In Windows the same request just hangs.

The same requests with ` ssh_flags=-vvv`

QEMU

```julia
# mostly same up to here
debug2: exec request accepted on channel 0
debug2: channel 0: read<=0 rfd 4 len 0
debug2: channel 0: read failed
debug2: channel 0: chan_shutdown_read (i0 o0 sock -1 wfd 4 efd 6 [write])
debug2: channel 0: input open -> drain
debug2: channel 0: ibuf empty
debug2: channel 0: send eof
debug3: send packet: type 96
debug2: channel 0: input drain -> closed
1-element Vector{Int64}:
 2

```

Windows

```julia
# mostly same up to here
debug2: exec request accepted on channel 0
debug3: receive packet: type 98
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug3: receive packet: type 98
debug1: client_input_channel_req: channel 0 rtype eow@openssh.com reply 0
debug2: channel 0: rcvd eow
debug2: channel 0: close_read
debug2: channel 0: input open -> closed
debug3: receive packet: type 96
debug2: channel 0: rcvd eof
debug2: channel 0: output open -> drain
debug2: channel 0: obuf empty
debug2: channel 0: close_write
debug2: channel 0: output drain -> closed
debug3: receive packet: type 97
debug2: channel 0: rcvd close
debug3: channel 0: will not send data after close
debug2: channel 0: almost dead
debug2: channel 0: gc: notify user
debug2: channel 0: gc: user detached
debug2: channel 0: send close
debug3: send packet: type 97
debug2: channel 0: is dead
debug2: channel 0: garbage collecting
debug1: channel 0: free: client-session, nchannels 1
debug3: channel 0: status: The following connections are open:
  #0 client-session (t4 r0 i3/0 o3/0 fd -1/-1 cc -1)

debug3: send packet: type 1
debug3: fd 0 is not O_NONBLOCK
debug3: fd 1 is not O_NONBLOCK
Transferred: sent 2088, received 2924 bytes, in 65.7 seconds
Bytes per second: sent 31.8, received 44.5
debug1: Exit status 1
# and hangs

```

I’ve tried different sshs builds but that made no difference

C:\Users\matt\Git\usr\bin\ssh.exe # OpenSSH\_8.8p1, OpenSSL 1.1.1l 24 Aug 2021

C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer\Git\usr\bin\ssh.exe # OpenSSH\_8.7p1, OpenSSL 1.1.1k 25 Mar 2021

C:\Users\matt\AppData\Local\Atlassian\SourceTree\git\_local\usr\bin\ssh.exe # OpenSSH\_8.4p1, OpenSSL 1.1.1j 16 Feb 2021

The Linux one is OpenSSH\_8.4p1 Debian-5, OpenSSL 1.1.1k 25 Mar 2021