Using many markers with leaflet in combination with shiny server

Question

I developed a Shiny-app where I make use of the leaflet package to plot a large nr of point (~25.000) on a geographical background. When I start the app from R-studio it all works very well. On the same server I have a shiny-server running. I deployd several apps on this server without any problems. I deployd the app on the shiny-server to make it available for end-users.

The issue
On shiny-server it looks like the app has a problems handling the number of markers (~25.000). The app 'hangs', I can't do anything, but restart the app. With a smaller number of points (<10.000) there is no problem.
I couldn't find this problem anywhere else.

Any ideas on what the problem is and how to solve it?

Here is my code I used to test the problem

shinyServer(function(input, output) {

     # Deel Interactive Map 
     plot_data <- reactive({
          columns <- c("lng",
                       "lat",
                       "perc_gtv");
          dt_installaties[1:input$nr_points,
                          columns,
                          with=FALSE];

     })

     output$map_branche <- renderLeaflet({
          leaflet() %>% 
               setView(lng = 5.5, 
                       lat = 52.5, 
                       zoom = 8) %>%
               addProviderTiles("OpenStreetMap.HOT") 

     })
     # Observer that changes the markers as the nr of points is 
     # being changed
     observe({
          pal <- colorBin(palette = c("red","green"),
                          domain = c(0,200),
                          bins = 7)
          leafletProxy("map_branche",
                       data = plot_data()) %>%
               clearMarkers() %>%
               addCircleMarkers(
                    lng = ~lng, 
                    lat = ~lat,
                    color = ~pal(perc_gtv),
                    fillOpacity = 0.9) 


     })

})



shinyUI(
     fluidPage(
          fluidRow(
               numericInput(
                    "nr_points",
                    label = h4("Points to plot"),
                    value = 5000,
                    min = 1,
                    max = nrow(dt_installaties)

               )
          ),
          mainPanel(
               leafletOutput("map_branche")
          )
     )

)

My configuration

• platform: x86_64-redhat-linux-gnu
• R: 3.2.2 R-studio: 0.98.1103
• Leaflet: 1.0.0
• Shiny: 0.12.2
• Shiny-server: public/free version