R's shiny app goes grey when deployed, works fine locally

Question

I've created two shiny apps running on shinyapps.io and both have the same problem that I haven't been able to solve: after a few mins into an active instance of the web app (a few mins after navigating to the web app in a browser), the screen goes grey. This problem happens when I navigate to the website of the deployed app, but when I run the app from RStudio, the browser window that pops up doesn't turn grey and behaves as it should.

Many people have posted on google groups, stackoverflow, and github about this problem. I've tried all of the relevant proposed solutions for how to fix it and none of them have worked for me:

• Screen may be turning grey because of an error in the ui or server code I wrote. The proposed solution is to run

  shinyapps::showLogs()

according to advice found here. But I've done this, and it doesn't output any error messages (see below).

• According to the rstudio shiny help page titled 'Scaling and Performance Tuning with shinyapps.io' under the heading 'Troubleshooting' (sorry, stackoverflow won't let me post more than 1 link), the cause of problem might be that my app is using too much memory and the shinyapps.io server kills the instance. I've done the two things they suggest, increasing the size of the application instance and decreasing the number of workers per application instance. Neither have fixed the issue. I have a feeling this isn't the problem because one of my apps is extremely simple and the calculations it makes are done within a second or two when run locally. I've also checked out the memory usage of the apps on the shiny dashboard and the usage is no where near the memory limit.

Any suggestions of what might be going wrong or what to change are greatly appreciated!

Output from shinyapps::showLogs() :

2016-01-09T02:42:48.551801+00:00 shinyapps[67824]: Starting R with process ID: '26'
2016-01-09T02:42:48.556484+00:00 shinyapps[67824]: 
2016-01-09T02:42:48.556486+00:00 shinyapps[67824]: Listening on http://0.0.0.0:53774
2016-01-09T02:43:40.334353+00:00 shinyapps[67824]: R version: 3.1.2
2016-01-09T02:43:40.334428+00:00 shinyapps[67824]: shiny version: 0.11.1
2016-01-09T02:43:40.334430+00:00 shinyapps[67824]: rmarkdown version: NA
2016-01-09T02:43:40.334431+00:00 shinyapps[67824]: knitr version: NA
2016-01-09T02:43:40.334442+00:00 shinyapps[67824]: jsonlite version: 0.9.14
2016-01-09T02:43:40.334443+00:00 shinyapps[67824]: RJSONIO version: 1.3.0
2016-01-09T02:43:40.334444+00:00 shinyapps[67824]: htmltools version: 0.2.6
2016-01-09T02:43:40.582614+00:00 shinyapps[67824]: Using jsonlite for JSON processing
2016-01-09T02:43:40.586355+00:00 shinyapps[67824]: 
2016-01-09T02:43:40.586357+00:00 shinyapps[67824]: Starting R with process ID: '36'
2016-01-09T02:43:40.590767+00:00 shinyapps[67824]: 
2016-01-09T02:43:40.590769+00:00 shinyapps[67824]: Listening on http://0.0.0.0:33335
2016-01-09T03:11:48.268226+00:00 shinyapps[67824]: R version: 3.1.2
2016-01-09T03:11:48.268317+00:00 shinyapps[67824]: shiny version: 0.11.1
2016-01-09T03:11:48.268318+00:00 shinyapps[67824]: rmarkdown version: NA
2016-01-09T03:11:48.268335+00:00 shinyapps[67824]: knitr version: NA
2016-01-09T03:11:48.268336+00:00 shinyapps[67824]: jsonlite version: 0.9.14
2016-01-09T03:11:48.268337+00:00 shinyapps[67824]: RJSONIO version: 1.3.0
2016-01-09T03:11:48.268338+00:00 shinyapps[67824]: htmltools version: 0.2.6
2016-01-09T03:11:48.515347+00:00 shinyapps[67824]: Using jsonlite for JSON processing
2016-01-09T03:11:48.519056+00:00 shinyapps[67824]: 
2016-01-09T03:11:48.519058+00:00 shinyapps[67824]: Starting R with process ID: '46'
2016-01-09T03:11:48.523399+00:00 shinyapps[67824]: 
2016-01-09T03:11:48.523401+00:00 shinyapps[67824]: Listening on http://0.0.0.0:37152
2016-01-16T01:13:14.357697+00:00 shinyapps[67824]: R version: 3.1.2
2016-01-16T01:13:14.357788+00:00 shinyapps[67824]: shiny version: 0.11.1
2016-01-16T01:13:14.357790+00:00 shinyapps[67824]: rmarkdown version: NA
2016-01-16T01:13:14.357791+00:00 shinyapps[67824]: knitr version: NA
2016-01-16T01:13:14.357792+00:00 shinyapps[67824]: jsonlite version: 0.9.14
2016-01-16T01:13:14.357809+00:00 shinyapps[67824]: RJSONIO version: 1.3.0
2016-01-16T01:13:14.357811+00:00 shinyapps[67824]: htmltools version: 0.2.6
2016-01-16T01:13:14.795787+00:00 shinyapps[67824]: Using jsonlite for JSON processing
2016-01-16T01:13:14.799494+00:00 shinyapps[67824]: 
2016-01-16T01:13:14.799495+00:00 shinyapps[67824]: Starting R with process ID: '11'
2016-01-16T01:13:14.806392+00:00 shinyapps[67824]: 
2016-01-16T01:13:14.806394+00:00 shinyapps[67824]: Listening on http://0.0.0.0:49762
2016-01-17T06:48:58.595979+00:00 shinyapps[67824]: R version: 3.1.2
2016-01-17T06:48:58.596062+00:00 shinyapps[67824]: shiny version: 0.11.1
2016-01-17T06:48:58.596064+00:00 shinyapps[67824]: rmarkdown version: NA
2016-01-17T06:48:58.596065+00:00 shinyapps[67824]: knitr version: NA
2016-01-17T06:48:58.596077+00:00 shinyapps[67824]: jsonlite version: 0.9.14
2016-01-17T06:48:58.596078+00:00 shinyapps[67824]: RJSONIO version: 1.3.0
2016-01-17T06:48:58.596079+00:00 shinyapps[67824]: htmltools version: 0.2.6
2016-01-17T06:48:58.999625+00:00 shinyapps[67824]: Using jsonlite for JSON processing
2016-01-17T06:48:59.003284+00:00 shinyapps[67824]: 
2016-01-17T06:48:59.003287+00:00 shinyapps[67824]: Starting R with process ID: '11'
2016-01-17T06:48:59.010065+00:00 shinyapps[67824]: 
2016-01-17T06:48:59.010067+00:00 shinyapps[67824]: Listening on http://0.0.0.0:37097

Here's an example of one of the problematic shiny apps: https://rosemarie-p-b-scott.shinyapps.io/OM_2266/

Answer 1

I don't know what exactly your app should be doing, but it seems to work fine for me as well. As far as I can tell your log doesn't show any errors either.

Might this be a timing issue? After 15 minutes of inactivity your app is put to sleep and when you surpass your active hours with a free account your app will not work either. Checkout the shinyapps user guide section 3.3 http://docs.rstudio.com/shinyapps.io/applications.html#application-life-cycle for more details

After the time out I see a greyed out version of the app screen with a message "Disconnected from the server" and a "reload" button. Is that how it looks to you?

I don't know how this looks when you use up all your active hours and I'm not going to try. You have to test this yourself.