R shiny: How to debug deployed app?

Question

I created an R shiny application and it runs perfectly on my machine. Also it is deployed successfully on the shinyapps.io server. However when I try to click one of the buttons to perform a task, the screen grays out (hangs). The same task is completed when I run my app locally. I can't see where the error lies because it is successfully run on my local machine. Any ideas how I can debug this?

This is the log of my application:

2015-07-07T21:52:53.949714+00:00 shinyapps[50164]: 
2015-07-07T21:52:53.950026+00:00 shinyapps[50164]: 
2015-07-07T21:52:53.839040+00:00 shinyapps[50164]: The following object is masked from ‘package:stats’:
2015-07-07T21:52:53.949719+00:00 shinyapps[50164]: 
2015-07-07T21:52:53.960914+00:00 shinyapps[50164]:     isNamespaceLoaded
2015-07-07T21:52:53.949718+00:00 shinyapps[50164]: Attaching package: ‘pkgmaker’
2015-07-07T21:52:53.960916+00:00 shinyapps[50164]: 
2015-07-07T21:52:53.950023+00:00 shinyapps[50164]: The following object is masked from ‘package:S4Vectors’:
2015-07-07T21:52:54.666591+00:00 shinyapps[50164]: NMF - BioConductor layer [OK] | Shared memory capabilities [NO: bigmemory] | Cores 15/16
2015-07-07T21:52:54.666968+00:00 shinyapps[50164]:   To enable shared memory capabilities, try: install.extras('
2015-07-07T21:52:54.666971+00:00 shinyapps[50164]: NMF
2015-07-07T21:52:54.666973+00:00 shinyapps[50164]: ')
2015-07-07T21:52:54.672080+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.672084+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.672634+00:00 shinyapps[50164]: The following object is masked from ‘package:Rgraphviz’:
2015-07-07T21:52:54.672636+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.672637+00:00 shinyapps[50164]:     name
2015-07-07T21:52:54.672638+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.676643+00:00 shinyapps[50164]: The following objects are masked from ‘package:topGO’:
2015-07-07T21:52:54.676645+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.672083+00:00 shinyapps[50164]: Attaching package: ‘NMF’
2015-07-07T21:52:54.676647+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.680862+00:00 shinyapps[50164]: The following object is masked from ‘package:IRanges’:
2015-07-07T21:52:54.680864+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.680865+00:00 shinyapps[50164]:     compare
2015-07-07T21:52:54.680866+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.682353+00:00 shinyapps[50164]: The following objects are masked from ‘package:S4Vectors’:
2015-07-07T21:52:54.682355+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.682356+00:00 shinyapps[50164]:     compare, nrun
2015-07-07T21:52:54.705236+00:00 shinyapps[50164]: Loading required package: KEGGgraph
2015-07-07T21:52:54.713283+00:00 shinyapps[50164]: Loading required package: XML
2015-07-07T21:52:54.676646+00:00 shinyapps[50164]:     algorithm, algorithm<-
2015-07-07T21:52:54.682357+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.974597+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.974601+00:00 shinyapps[50164]: Attaching package: ‘XML’
2015-07-07T21:52:54.974602+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.975059+00:00 shinyapps[50164]: The following object is masked from ‘package:graph’:
2015-07-07T21:52:54.975061+00:00 shinyapps[50164]: 
2015-07-07T21:52:54.975062+00:00 shinyapps[50164]:     addNode
2015-07-07T21:52:54.975063+00:00 shinyapps[50164]: 
2015-07-07T21:52:55.046069+00:00 shinyapps[50164]: 
2015-07-07T21:52:55.046423+00:00 shinyapps[50164]: The following object is masked from ‘package:NMF’:
2015-07-07T21:52:55.046426+00:00 shinyapps[50164]:     name<-
2015-07-07T21:52:55.046427+00:00 shinyapps[50164]: 
2015-07-07T21:52:55.046425+00:00 shinyapps[50164]: 
2015-07-07T21:52:55.046064+00:00 shinyapps[50164]: 
2015-07-07T21:52:55.046068+00:00 shinyapps[50164]: Attaching package: ‘KEGGgraph’
2015-07-07T21:52:55.235031+00:00 shinyapps[50164]: Warning in run(timeoutMs) :
2015-07-07T21:52:55.235050+00:00 shinyapps[50164]:   replacing previous import by ‘dendextend::%>%’ when loading ‘NMF’
2015-07-07T21:52:55.235175+00:00 shinyapps[50164]: Warning in run(timeoutMs) :
2015-07-07T21:52:55.235177+00:00 shinyapps[50164]:   replacing previous import by ‘dendextend::cutree’ when loading ‘NMF’

Thanks

Answer 1

Apparently, it was a memory issue, 500MB of memory was insufficient for this application. I changed the instance size from medium (default for free users) to xx large and it worked.

Probably Warning in run(timeoutMs) in the logs indicates that you are out of memory.