R Shiny app - big mysql query results in page not loading

Question

I have a Shiny app which uses two mysql queries to retrieve data and the app works well when run from RStudio. (one of the queries is taking around 8 minutes)

But when I move it on a Shiny Server and access http://ip/myapp/, the page it's loading for a while and the I get "Problem loading page" .

I assume it's because the long query. Is there some good way to deal with this situation, when long queries have to be made from Shiny app?

-- (running locally app.R from RStudio, works fine)

Info about the app:

• Location: /srv/shiny-server/myapp

• Filename: app.r

• File structure:

  -- load libraries

  library(shiny)

  ...

  -- Connection and queries

  con <- dbConnect(MySQL(),
                   user = '#',
                   password = '#',
                   host = '#',
                   dbname='#')
  
  tickets<-dbGetQuery(con, "Select * from table")
  dbDisconnect (con)
  con <- dbConnect(MySQL(),
                   user = '#',
                   password = '#',
                   host = '#',
                   dbname='#')
  -- long query
  issues_speed_unique<-unique(na.omit(dbGetQuery(con,"Select * from table2")))
  dbDisconnect (con) 
  
  some aggregations....
  

  -- Server code

  shinyServer(
    function(input,output){
       ...
  

  -- ui code

  shinyUI(fluidPage(
       ...
  
  shinyApp(ui = ui, server = server)