App greyed out - SockJS conn is acquired but immediately released.

[ZmG]

Background: Built shiny servers versions: v1.5.7.907, v1.5.8.921

Build shiny server from source code for s390x architecture including installing node using install-node.sh for s390x architecture. NGINX sitting in front of Shiny Server.

Problem: When launching app, app loads but it greys out. SockJS conn is acquired but immediately released.

[2018-10-17T05:02:04.009] [INFO] shiny-server - Shiny Server v1.5.7.0 (Node.js v8.10.0)
[2018-10-17T05:02:04.010] [DEBUG] shiny-server - No pidfile requested
[2018-10-17T05:02:04.011] [INFO] shiny-server - Using config file "/etc/shiny-server/shiny-server.conf"
[2018-10-17T05:02:04.078] [WARN] shiny-server - Running as root unnecessarily is a security risk! You could be running more securely as non-root.
[2018-10-17T05:02:04.081] [INFO] shiny-server - Starting listener on 0.0.0.0:3838
[2018-10-17T05:02:04.084] [DEBUG] shiny-server - No access log configured
[2018-10-17T05:02:04.084] [TRACE] shiny-server - Config loaded
[2018-10-17T05:02:07.758] [TRACE] shiny-server - Spawning new instance
[2018-10-17T05:02:07.759] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 1 HTTP, 0 WebSocket, 0 pending.
[2018-10-17T05:02:07.759] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring pending port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:07.762] [TRACE] shiny-server - 
[2018-10-17T05:02:07.763] [TRACE] shiny-server - Starting R
[2018-10-17T05:02:07.764] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:07.766] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:07.814] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:07.815] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:07.865] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:07.866] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:07.966] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:07.967] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:08.068] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:08.068] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:08.169] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:08.169] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:08.269] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:08.269] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:08.369] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:08.369] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:08.569] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:08.570] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:08.770] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:08.771] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:09.072] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:09.073] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:09.216] [TRACE] shiny-server - Using R version: 3.4.3
[2018-10-17T05:02:09.217] [TRACE] shiny-server - Using shiny version: 1.1.0
[2018-10-17T05:02:09.317] [TRACE] shiny-server - R process spawned with PID 20224
[2018-10-17T05:02:09.372] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:09.373] [TRACE] shiny-server - Failed to connect to port 38747
[2018-10-17T05:02:09.674] [TRACE] shiny-server - Attempting to connect to port 38747
[2018-10-17T05:02:09.682] [TRACE] shiny-server - Successfully connected to port 38747 after 1900ms
[2018-10-17T05:02:09.683] [TRACE] shiny-server - Proxying request: /
[2018-10-17T05:02:09.683] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:09.687] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:09.804] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:09.809] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:09.811] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.069] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:10.069] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.069] [TRACE] shiny-server - Proxying request: /shared/json2-min.js
[2018-10-17T05:02:10.069] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:10.070] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:10.150] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:10.151] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:10.152] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.328] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:10.328] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.328] [TRACE] shiny-server - Proxying request: /shared/shiny.css
[2018-10-17T05:02:10.329] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:10.329] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:10.348] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:10.349] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:10.353] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.534] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:10.534] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.534] [TRACE] shiny-server - Proxying request: /shared/ionrangeslider/css/ion.rangeSlider.skinShiny.css
[2018-10-17T05:02:10.534] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:10.535] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:10.560] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:10.561] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:10.561] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.682] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:10.682] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.683] [TRACE] shiny-server - Proxying request: /shared/bootstrap/css/bootstrap.min.css
[2018-10-17T05:02:10.683] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:10.683] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:10.694] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:10.697] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:10.699] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.728] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:10.728] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.728] [TRACE] shiny-server - Proxying request: /shared/ionrangeslider/css/ion.rangeSlider.css
[2018-10-17T05:02:10.728] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:10.729] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:10.735] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:10.736] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:10.736] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.989] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:10.989] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:10.989] [TRACE] shiny-server - Proxying request: /shared/shiny.min.js
[2018-10-17T05:02:10.990] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:10.990] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:11.020] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:11.022] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:11.024] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:11.024] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 2 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.024] [TRACE] shiny-server - Proxying request: /shared/ionrangeslider/js/ion.rangeSlider.min.js
[2018-10-17T05:02:11.024] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:11.024] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:11.025] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.029] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:11.029] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 2 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.029] [TRACE] shiny-server - Proxying request: /shared/bootstrap/js/bootstrap.min.js
[2018-10-17T05:02:11.029] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:11.029] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:11.032] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:11.032] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 3 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.032] [TRACE] shiny-server - Proxying request: /shared/strftime/strftime-min.js
[2018-10-17T05:02:11.032] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:11.032] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:11.042] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:11.043] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:11.044] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 2 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.045] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:11.045] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 3 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.046] [TRACE] shiny-server - Proxying request: /shared/bootstrap/shim/html5shiv.min.js
[2018-10-17T05:02:11.046] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:11.046] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:11.048] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:11.048] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:11.050] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 2 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.060] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:11.061] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:11.062] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.071] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:11.072] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:11.072] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.085] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:11.086] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.086] [TRACE] shiny-server - Proxying request: /shared/bootstrap/shim/respond.min.js
[2018-10-17T05:02:11.086] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:11.086] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:11.090] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:11.091] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:11.091] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.232] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:11.232] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:11.234] [TRACE] shiny-server - Proxying request: /shared/jquery.min.js
[2018-10-17T05:02:11.234] [TRACE] shiny-server - http_proxy event: start
[2018-10-17T05:02:11.235] [TRACE] shiny-server - http_proxy event: proxyReq
[2018-10-17T05:02:11.251] [TRACE] shiny-server - http_proxy event: proxyRes
[2018-10-17T05:02:11.254] [TRACE] shiny-server - http_proxy event: end
[2018-10-17T05:02:11.256] [TRACE] shiny-server - Worker #35c3e650048147cd releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2018-10-17T05:02:13.386] [DEBUG] shiny-server - Creating a new robust connection: mA4FWjcS3QdVuC3sYk
[2018-10-17T05:02:13.724] [TRACE] shiny-server - Accepted SockJS connection for /rstudio/myshinyApp/__sockjs__/n=mA4FWjcS3QdVuC3sYk/265/6we2wbuj/xhr
[2018-10-17T05:02:13.744] [TRACE] shiny-server - Reusing existing instance
[2018-10-17T05:02:13.744] [TRACE] shiny-server - Worker #35c3e650048147cd releasing pending port. 0 HTTP, 0 WebSocket, 0 pending.
[2018-10-17T05:02:13.744] [TRACE] shiny-server - No clients connected to worker #35c3e650048147cd. Starting timer
[2018-10-17T05:02:13.744] [TRACE] shiny-server - Worker #35c3e650048147cd acquiring sock port. 0 HTTP, 1 WebSocket, 0 pending.
[2018-10-17T05:02:13.750] [TRACE] shiny-server - Worker #35c3e650048147cd releasing sock port. 0 HTTP, 0 WebSocket, 0 pending.
[2018-10-17T05:02:13.757] [TRACE] shiny-server - No clients connected to worker #35c3e650048147cd. Starting timer
[2018-10-17T05:02:18.753] [TRACE] shiny-server - Withholding event 'end' from robust connection mA4FWjcS3QdVuC3sYk
[2018-10-17T05:02:18.753] [TRACE] shiny-server - Withholding event 'close' from robust connection mA4FWjcS3QdVuC3sYk
[2018-10-17T05:02:18.757] [TRACE] shiny-server - Timeout expired. Killing process.
[2018-10-17T05:02:18.757] [TRACE] shiny-server - Interrupting process on socket port 38747
[2018-10-17T05:02:18.757] [TRACE] shiny-server - Sending SIGINT to 20224
[2018-10-17T05:02:18.857] [TRACE] shiny-server - Port 38747 returned
[2018-10-17T05:02:18.857] [TRACE] shiny-server - Port 38747 proxy closed
[2018-10-17T05:02:18.858] [TRACE] shiny-server - Normal exit, deleting log file /var/log/shiny-20181017-050207-38747.log
[2018-10-17T05:02:33.754] [DEBUG] shiny-server - Closing robust connection mA4FWjcS3QdVuC3sYk

Debugging

1. Built both v1.5.7.907 and v1.5.8.921 - same issue

2. Tried different configuration options in NGINX including directives to upgrade to websocket protocols.

3. Surpassed Nginx, so traffic flows directly to shiny server. Browser -> Shiny-server.

Errors:

[2018-10-17T05:15:33.334] [DEBUG] shiny-server - HTTP client error (undefined): Parse Error
[2018-10-17T05:15:33.345] [DEBUG] shiny-server - HTTP client error (undefined): Parse Error
[2018-10-17T05:15:55.943] [DEBUG] shiny-server - HTTP client error (undefined): Parse Error

4. Attempted to disable websockets using disable_protocols

[jcheng5]

Try adding the line preserve_logs true; to your /etc/shiny-server-client/shiny-server-client.conf and reloading the server. Then get the app to load again, and look in the /var/log/shiny-server/ (not the shiny-server-client.log file) directory for clues. It's likely that the app is hitting an unhandled exception and intentionally ending the session in response.

[ZmG]

Thanks for the quick response. Added the preserve_logs true; to /etc/shiny-server/shiny-server.conf.

The output from /var/log/shiny-server/myshinyApp-xx-20181017-055013-37535.log is not very helpful:

su: ignoring --preserve-environment, it's mutually exclusive with --login

Listening on http://127.0.0.1:37535

Execution halted

Is there an additional configuration that could enable more verbose output in the app log?

[jcheng5]

Hmmm, that indicates that everything terminated normally. There's nothing in the browser's JavaScript console when it disconnects?

[SeeNewt]

Did you ever figure out what was going on here? I'm in a similar situation. In my case, the app runs fine in general, but I'm getting this error when restoring a bookmarked session. It doesn't happen with every bookmarked session, only ones after I've clicked a certain action button. I've dug in as best I can, and can't find any leads in the logs. Any ideas?

There's nothing noteworthy in the browser console:

Here's the relevant part of the server log:

[cnewton1@NCIENDEVAPP03 ~]$ tail -100  /var/log/shiny-server.log
[2019-04-12T14:18:24.781] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:24.783] [TRACE] shiny-server - Proxying request: /shared/strftime/strftime-min.js
[2019-04-12T14:18:24.783] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:24.784] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:24.791] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:24.791] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:24.792] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:24.944] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:24.944] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:24.944] [TRACE] shiny-server - Proxying request: /shared/bootstrap/js/bootstrap.min.js
[2019-04-12T14:18:24.945] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:24.945] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:24.953] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:24.954] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:24.955] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:25.057] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:25.057] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:25.058] [TRACE] shiny-server - Proxying request: /shared/bootstrap/shim/html5shiv.min.js
[2019-04-12T14:18:25.058] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:25.058] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:25.065] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:25.066] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 2 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:25.066] [TRACE] shiny-server - Proxying request: /shared/bootstrap/shim/respond.min.js
[2019-04-12T14:18:25.066] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:25.067] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:25.067] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:25.068] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:25.072] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 1 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:25.074] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:25.074] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 2 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:25.074] [TRACE] shiny-server - Proxying request: /Navigant.png
[2019-04-12T14:18:25.074] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:25.075] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:25.078] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:25.079] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:25.079] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 1 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:25.087] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:25.088] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:25.088] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:25.101] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:25.102] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:25.102] [TRACE] shiny-server - Proxying request: /shared/shiny.min.js.map
[2019-04-12T14:18:25.102] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:25.102] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:25.109] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:25.338] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:25.338] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 2 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:25.338] [TRACE] shiny-server - Proxying request: /crosstalk-1.0.0/js/crosstalk.min.js.map
[2019-04-12T14:18:25.338] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:25.338] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:25.345] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:25.346] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:25.346] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 1 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:25.548] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:25.549] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:26.080] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:26.080] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:26.080] [TRACE] shiny-server - Proxying request: /shinythemes/fonts/Roboto_400.ttf
[2019-04-12T14:18:26.080] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:26.081] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:26.081] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:26.082] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 2 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:26.082] [TRACE] shiny-server - Proxying request: /shinythemes/fonts/Roboto_500.ttf
[2019-04-12T14:18:26.082] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:26.082] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:26.088] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:26.088] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 3 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:26.088] [TRACE] shiny-server - Proxying request: /shinythemes/fonts/Roboto_700.ttf
[2019-04-12T14:18:26.088] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:26.088] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:26.093] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:26.094] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:26.094] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 2 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:26.100] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:26.100] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:26.100] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 1 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:26.105] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:26.105] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:26.105] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:26.185] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:26.185] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring http port. 1 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:26.185] [TRACE] shiny-server - Proxying request: /shared/bootstrap/css/bootstrap.min.css.map
[2019-04-12T14:18:26.186] [TRACE] shiny-server - http_proxy event: start
[2019-04-12T14:18:26.186] [TRACE] shiny-server - http_proxy event: proxyReq
[2019-04-12T14:18:26.193] [TRACE] shiny-server - http_proxy event: proxyRes
[2019-04-12T14:18:26.853] [TRACE] shiny-server - http_proxy event: end
[2019-04-12T14:18:26.853] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing http port. 0 HTTP, 0 WebSocket, 1 pending.
[2019-04-12T14:18:27.325] [DEBUG] shiny-server - Creating a new robust connection: pGZFGJtWkYBUpqJ0Ti
[2019-04-12T14:18:27.784] [TRACE] shiny-server - Accepted SockJS connection for /ShinyApps/NAVsamplr_Test/__sockjs__/n=pGZFGJtWkYBUpqJ0Ti/979/1h1jxta0/xhr_streaming
[2019-04-12T14:18:27.805] [TRACE] shiny-server - Reusing existing instance
[2019-04-12T14:18:27.805] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing pending port. 0 HTTP, 0 WebSocket, 0 pending.
[2019-04-12T14:18:27.805] [TRACE] shiny-server - No clients connected to worker #f7a1da87230d90dc. Starting timer
[2019-04-12T14:18:27.805] [TRACE] shiny-server - Worker #f7a1da87230d90dc acquiring sock port. 0 HTTP, 1 WebSocket, 0 pending.
[2019-04-12T14:18:28.525] [TRACE] shiny-server - Worker #f7a1da87230d90dc releasing sock port. 0 HTTP, 0 WebSocket, 0 pending.
[2019-04-12T14:18:28.526] [TRACE] shiny-server - No clients connected to worker #f7a1da87230d90dc. Starting timer
[2019-04-12T14:18:28.769] [TRACE] shiny-server - Withholding event 'end' from robust connection pGZFGJtWkYBUpqJ0Ti
[2019-04-12T14:18:28.770] [TRACE] shiny-server - Withholding event 'close' from robust connection pGZFGJtWkYBUpqJ0Ti
[2019-04-12T14:18:43.771] [DEBUG] shiny-server - Closing robust connection pGZFGJtWkYBUpqJ0Ti
[2019-04-12T14:19:20.842] [WARN] shiny-server - No host header sent by user-agent check_http/v2.2.1 (nagios-plugins 2.2.1)
[2019-04-12T14:19:20.843] [WARN] shiny-server - No host header sent by user-agent check_http/v2.2.1 (nagios-plugins 2.2.1)

And here's the session log (the errors listed are resolved after loading the input data set, and do not prevent the session from continuing to run):

Attaching package: ‘shinydashboard’

The following object is masked from ‘package:graphics’:

    box

Attaching package: ‘DT’

The following objects are masked from ‘package:shiny’:

    dataTableOutput, renderDataTable

Attaching package: ‘dplyr’

The following objects are masked from ‘package:stats’:

    filter, lag

The following objects are masked from ‘package:base’:

    intersect, setdiff, setequal, union

Attaching package: ‘gridExtra’

The following object is masked from ‘package:dplyr’:

    combine

Listening on http://127.0.0.1:41933
Warning: Error in : slice condition does not evaluate to an integer or numeric vector.
  192: <Anonymous>
Warning: Error in : slice condition does not evaluate to an integer or numeric vector.
  192: <Anonymous>

[Ashish1981]

I am also facing the similar issue on s390x build. Any resolution to this..?