Disconnection (Reload) issue

shiny
shiny-server

#1

Hello,
I have an disconnect/reload issue about Shiny server.

Background: my application is designed to show/manipulate/query tables (I used DataTable) downloaded from a DB; the tables are quite big since there could be a lot of data in the DB.

Basically, I have these two situations:

  1. locally the web-app works without problems;
  2. on the server the same app contiues to disconnect showing the "Reload" message and it is impossible to work.

I tried to use different web browser and to change some settings in the configuration file of shiny-server but the problem still continues.
The IDE (RStudio) does not show any error; the only one that I receive is the "WebSocket" error which appears in the browser console.
I do not have anymore ideas since the issue comes up quite randomly so it is difficult to isolate the reason.

The only point which I do not deepen to much is the server-data infrastructure where the shiny server is installed.

Could the infrastructure affect the operation of my application?
Is there any configuration that I missed?

Thanks for any suggestion.


#2

hi @sitritini, did you see any errors in the log files?

The infrastructure can definitely affect your application. Since you are mentioning that the tables used can be quite big, it could be a memory issue.


#3

Hi,
thank you for the answer.
Below, there is the log of my server but it is not so helpful. It seems correct; the only strange row is the last one but I think that it is related to the closing of the brower.

Loading required package: DBI

Attaching package: ‘DT’

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

    dataTableOutput, renderDataTable


Attaching package: ‘shinyjs’

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

    show

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

    show

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

    runExample

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

    removeClass, show

Loading required package: RANN
Loading required package: NISTunits
Loading required package: pracma

Attaching package: ‘pracma’

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

    cross


Listening on http://127.0.0.1:37809

Execution halted

In the meanwhile, I am trying to check memory settings in order to understand if the problem is there o elsewhere.


#4

After running your app once, can you provide the output of sessioninfo::session_info()? There were some issues in httpuv (the web-serving package that Shiny uses) related to WebSockets that were fixed recently. Installing the latest version of httpuv (1.4.4.1) from CRAN may help.

If you could also open up the JavaScript console in your web browser and see if there are any errors there, that would help.