Hello everyone,
I am reaching out for insights or solutions to an issue we are encountering with our ShinyProxy deployment. We are running ShinyProxy version 3.0.2 on an AWS EC2 instance with AWS Linux 2023, and we’ve been observing that occassionally our Shiny app stops unexpectedly and unpredictably after running normally for some (or better, the most of) time. Afterwards, the users are always able to reload the app successfully.
There are no errors in the container logs, and the container monitoring suggests that the containers are simply being stopped. However, we have noticed the following error messages in the ShinyProxy logs:
- A
DockerRequestExceptionindicating that Shinyproxy is attempting to access information about a Docker container that appears to be non-existent:
Caused by: com.spotify.docker.client.exceptions.DockerRequestException: Request error: GET unix://localhost:80/containers/{container_id}/json: 404, body: {
“message”: “No such container: {container_id}”
}
- An error related to a failed proxy request, potentially due to a prematurely closed connection:
ERROR 7801 --- [XNIO-1 I/O-2] io.undertow.proxy : UT005028: Proxy request to /proxy_endpoint/{session_id}/highcharts-x.y.z/modules/timeline.js failed
java.io.IOException: UT001000: Connection closed
In the ShinyProxy logs, we found additionally some reoccurring errors, which are (at least time-)independent to the “lost” containers (still, we have the suspicion they have the same root):
023-11-06 14:10:33.672 ERROR 7816 --- [pool-1-thread-13] e.o.containerproxy.service.ProxyService : [user=user_id proxyId=proxy_id specId=spec_id] Failed to remove proxy
and
eu.openanalytics.containerproxy.ContainerProxyException: Failed to stop container
We also observed several Exception handling request to..., e.g.:
023-10-10 21:43:52.779 ERROR 7990 --- [XNIO-1 task-2] io.undertow.request : UT005023: Exception handling request to /proxy_endpoint/moin_static170rc3/favicon.ico
This error occurred with a range of other files (which are, by the way, not part of our app) as well, such as:
/proxy_endpoint/pics/reservation.png
/proxy_endpoint/moin_static157/robots.txt
/proxy_endpoint/images/ico_clear.gif
/proxy_endpoint/images/green_dot.gif
...
We have already double-checked the Docker and ShinyProxy configurations, found no significant resource constraints, and verified network settings. Nonetheless, the problem persists.
Has anyone experienced similar issues or could provide insights into what might be causing this problem? Any advice or suggestions would be greatly appreciated. Thank you in advance for your support! 
Best regards,
bathyscapher