Disconnecting from the server

[LiFE is A BeACH]

Hi everyone,

every time I open the url of my deployed Application it appear the error message "disconnected from the server- Reload". Did some one know what causes this could have. 

Thanks in advance!

[Joe Cheng]

Can you tell us the URL? Or is it private?

--
You received this message because you are subscribed to the Google Groups "Shiny - Web Framework for R" group.
To unsubscribe from this group and stop receiving emails from it, send an email to shiny-discus...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/shiny-discuss/a4daa4ef-63c1-45a0-ae0f-b230a8965a37%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[LiFE is A BeACH]

Of course,

https://ninamarkovic.shinyapps.io/prob_bakt/

[Jeff van Geete]

I am having this issue but with the shiny-server service on my aws instance.  able to launch the app np from rstudio-server, but when I cp over to the /srv/shiny-server/ folder it disconnects after 1 second.  best of all, no logs.  

[Joe Cheng]

Nina, the first step would be to consult your app logs, which you can access through shinyapps.io or alternatively from your local RStudio project via rsconnect::showLogs() (or a similarly named function, sorry, I'm on my phone). If there is no error or warning in the logs, is it possible your app uses a lot of memory (RAM)? You will also get disconnected if the app is too big for your instance size, which you can enlarge also via shinyapps.io.

Jeff, are you looking under /var/log/shiny-server/*.log? (As opposed to /var/log/shiny-server.log) Do you see anything in your browser's JavaScript error console?

To view this discussion on the web visit https://groups.google.com/d/msgid/shiny-discuss/28ddefee-adc0-4be7-a90b-ecf764146f3c%40googlegroups.com.

[Pawan Dwivedi]

Did you find a solution to this? I am having the same issue. I am trying to run a shiny app on aws shiny-server. The app UI is loaded but within 2-3 seconds I get a 'Disconnected from the server. Reload' message. Checked into /var/log/shiny-server.log and /var/log/shiny-server/*.log but nothing useful there.

[Joe Cheng]

What do you see in /var/log/shiny-server/*.log? No errors at all? You may need to add the line "preserve_logs true;" to your shiny-server.conf file.

To view this discussion on the web visit https://groups.google.com/d/msgid/shiny-discuss/461601c8-5cb7-4ceb-a222-c227b62ce07f%40googlegroups.com.

[Pawan Dwivedi]

Thanks, it is resolved. I added 'preserve_logs true' to shiny_server.conf file and 'sanitize_error false' to app.R, then it started creating logs in /var/log/shiny-server/*.log.

[Alla Sapozhnikova]

I am having the same issue. I keep getting the "Disconnected from the server: Reload message. This is how it looks in browser.

shiny-server.log seems to be clean. Here it is:

[2018-02-11 20:33:05.148] [INFO] shiny-server - Stopping listener on 0.0.0.0:3838

[2018-02-11 20:33:05.148] [INFO] shiny-server - Shutting down worker processes (with notification)

[2018-02-11 21:23:02.550] [INFO] shiny-server - Shiny Server v1.5.7.0 (Node.js v6.10.3)

[2018-02-11 21:23:02.552] [INFO] shiny-server - Using pidfile /data/shiny-server/run/shiny-server.pid

[2018-02-11 21:23:02.553] [INFO] shiny-server - Using config file "/etc/shiny-server/shiny-server.conf"

[2018-02-11 21:23:02.589] [INFO] shiny-server - Starting listener on 0.0.0.0:3838

[2018-02-11 21:30:39.034] [INFO] shiny-server - Stopping listener on 0.0.0.0:3838

[2018-02-11 21:30:39.035] [INFO] shiny-server - Shutting down worker processes (with notification)

[2018-02-11 21:31:22.573] [INFO] shiny-server - Shiny Server v1.5.7.0 (Node.js v6.10.3)

[2018-02-11 21:31:22.576] [INFO] shiny-server - Using pidfile /data/shiny-server/run/shiny-server.pid

[2018-02-11 21:31:22.576] [INFO] shiny-server - Using config file "/etc/shiny-server/shiny-server.conf"

[2018-02-11 21:31:22.614] [INFO] shiny-server - Starting listener on 0.0.0.0:3838

This is my app:

options(shiny.sanitize.errors = FALSE)

options(shiny.trace = TRUE)

library(shiny)

# Define UI for application that plots random distributions

#ui <- fluidPage(

ui <- bootstrapPage(

  "test",

 h3("URL components"),

  verbatimTextOutput("urlText"),

  "test",

browser()

)

server <- function(input, output,session) {

}

shinyApp(ui, server)

 

The app log shows the following:

 Listening on http://127.0.0.1:45704

SEND {"config":{"workerId":"","sessionId":"cc24c18a88fb9c8c8a049e7ef6b17b39","user":null}}

Execution halted

No error messages on the browser console. Browser log is attached.

This is my shiny-server.conf

# Instruct Shiny Server to run applications as the user "shiny"

run_as shiny;

preserve_logs true;

sanitize_errors false;

#app_init_timeout 60;

#app_idle_timeout 60;

#disable_protocols websocket xdr-polling xdr-streaming;

#disable_protocols websocket xdr-polling;

#disable_protocols xdr-streaming xhr-streaming iframe-eventsource iframe-htmlfile;

# Define a server that listens on port 3838

server {

  listen 3838;

  # Define a location at the base URL

  location /shiny {

    # Host the directory of Shiny Apps stored in this directory

    site_dir /data/shiny-apps;

    # Log all Shiny output to files in this directory

    log_dir /var/log/shiny-server;

    # When a user visits the base URL rather than a particular application,

    # an index of the applications available in this directory will be shown.

    directory_index off;

  }

}

Any help is very much appreciated.

Thank you.

[Alla Sapozhnikova]

I added shiny trace option to a shiny server and attached the shiny-server.log with the trace. 

These lines seem to be the ones where the "disconnect" happens

[2018-02-11 15:50:18.153] [TRACE] shiny-server - Withholding event 'end' from robust connection osbbL9achGVuE0zJiz

[2018-02-11 15:50:18.153] [TRACE] shiny-server - Withholding event 'close' from robust connection osbbL9achGVuE0zJiz

[2018-02-11 15:50:23.084] [TRACE] shiny-server - Timeout expired. Killing process.

[2018-02-11 15:50:23.084] [TRACE] shiny-server - Interrupting process on socket port 41961

[2018-02-11 15:50:23.084] [TRACE] shiny-server - Sending SIGINT to 47676

[2018-02-11 15:50:23.130] [TRACE] shiny-server - Port 41961 returned

[2018-02-11 15:50:23.130] [TRACE] shiny-server - Port 41961 proxy closed

[Joe Cheng]

Those messages all seem normal--that's just what happens when the client disconnects from the server. What's surprising to me is the shiny-server.log showing that the server is shutting down and starting up so often; were you causing shiny-server to restart in those instances? Or rebooting the entire server?

To view this discussion on the web visit https://groups.google.com/d/msgid/shiny-discuss/74045553-2de2-475a-ae01-e1cee1b07019%40googlegroups.com.

[Alla Sapozhnikova]

No, i did not do anything with the server, the log just shows the trace of what was happening when i was trying to run the hello app from the browser. Please note that nobody else was connected to the server or doing anything there.

Here is the corresponding trace from the hello app log

shiny@shiny:/home/shiny> cat /var/log/shiny-server/hello-shiny-20180211-155016-41961.log

Listening on http://127.0.0.1:41961

SEND {"config":{"workerId":"","sessionId":"c3ee046ea5cb4723f2d76eb564c94526","user":null}}

Execution halted

It looks to me that there is no data sent from the R session to the browser. And the only thing that happens right away is the error message "Disconnected from the server- Reload"

[Enisha Eshwar]

I had faced a similar issue, adding a few pointers which might help someone.

2 of my requests from the Shiny app were pretty heavy and taking a long while ~25-30s (check network logs on browser). After a while connection would get terminated with the error as below:
{"type":"close","code":3000,"reason":"No response from heartbeat","wasClean":true}

Shiny has few params related to heartbeat. Setting them is what helped me. Increase the value of 'sockjs_heartbeat_delay' in shiny-server.conf to a large number and the disconnect issue was not seen anymore. 

[Francesco]

Thanks for the tip, I am also struggling with disconnections - it would be interesting to know which combinations of `http_keepalive_timeout`,   `sockjs_heartbeat_delay`, and `sockjs_disconnect_delay` can work better with slow networks / aggressive proxies. My guest would have been to decrease the value of sockjs_heartbeat_delay, to keep the connection alive, but in your case you seem to get good results with larger values. I will try and see if it works for me as well.

Francesco