Signals Image Artist: Why am I seeing the error "SImA connection is broken" when attempting to login? – Revvity Signals

Keywords: SImA, Signals Image Artist, connection, is, broken, login, 502 Bad Gateway,

Details:

The error message SImA connection is broken is shown when you attempt to login to SImA. When clicking show details you then see the following:

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<!>/home/acapella/Acapella/AcapellaResources/AcapellaColumbusWebapp/ProcLib/columbus/util_treeview.proc(45) [columbus::nav_OpenBranch_inner]: 

<!>/home/acapella/Acapella/AcapellaResources/AcapellaColumbusWebapp/ProcLib/columbus/util_treeview.proc(62) [Columbus::nav_FetchList]: 

<!>/home/acapella/Acapella/AcapellaResources/AcapellaColumbusWebapp/ProcLib/columbus/navigator.proc(796) [::Eval]: Eval() script failed: 

<!>{inline eval script}(1) [Gemma::GetScreenList]: 

<!>/home/acapella/Acapella/AcapellaResources/AcapellaImageArtist/ProcLib/gemma/api_client.proc(472) [Gemma::Get]: 

<!>/home/acapella/Acapella/AcapellaResources/AcapellaImageArtist/ProcLib/gemma/api_client.proc(225) [Gemma::Request]: 

<!>/home/acapella/Acapella/AcapellaResources/AcapellaImageArtist/ProcLib/gemma/api_client.proc(93) [Gemma::RequestRaw]: 

<!>/home/acapella/Acapella/AcapellaResources/AcapellaImageArtist/ProcLib/gemma/api_client.proc(73) [::Error]: SImA API error 502 Content=<html>

<head><title>502 Bad Gateway</title></head>

<body>

<center><h1>502 Bad Gateway</h1></center>

<hr><center>nginx/1.20.1</center>

</body>

</html>

The error indicates that the client is unable to communicate with the upstream SImA server. Take the following steps to un-deploy and re-deploy the SImA stack:

login to SImA via SSH
list the containers associated with the SImA stack:

$ docker stack ps SImA

Check the output to assess if the containers are shutdown or running.
Navigate to the SImA installation directory (typically this is where the goods have been unzipped)
Undeploy the SImA stack using the undeploy.sh script

$ ./undeploy.sh

Wait for the stack to be terminated, then use the deploy.sh script to bring the SImA stack back up:

$ ./deploy.sh

You'll have to wait a few minutes for the stack to be brought back up.

Check the status of the containers associated with the SImA stack:

$ docker stack ps SImA

Please note that if you're not using the deploy.sh and undeploy.sh scripts to re-deploy the SImA stack then there is a nuance in the way the SImA stack is brought down when using docker stack rm SImA (or if simply powering down) which can leave the stack in a semi-deployed state. This is because the loki container needs to be brought down last, but Docker provides no functionality for determining the order in which the containers are stopped, hence loki may not be brought down last. When Docker redeploys the stack after the reboot, it will essentially restore the stack to the bad state, which can also be the cause of the "SImA connection is broken" error.

For access to the deploy and undeploy scripts see the following post:

I'm using SImA 1.0, what is the recommended method to undeploy and redeploy the SImA stack?

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