OpenTelemetry traces on server starting up #4381

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1. cpsievert commented on May 11, 2026

   

   cpsievert

   on May 11, 2026

   Collaborator

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   Hi @marcosnav, is this something you're noticing with a minimal Hello World Shiny app? Or is this something specific to a more complex app? If you are doing something like reading in lots of data at the top level of your server function, then that could explain the startup time here.
2. marcosnav commented on May 13, 2026

   

   marcosnav

   on May 13, 2026

   Author

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   Hi @cpsievert, the shared example is a quite complex app. But the same can be seen in simple apps, like the one I'm sharing below.

   library(shiny)
   library(otel)
   library(otelsdk)
   
   ui <- fluidPage(
     titlePanel("Hello Shiny"),
     sidebarLayout(
       sidebarPanel(
         sliderInput("bins", "Number of bins:", min = 1, max = 50, value = 30)
       ),
       mainPanel(
         plotOutput("distPlot")
       )
     )
   )
   
   .shiny_startup_span <- otel::start_span(
     "shiny_framework_startup",
     attributes = list(app.instrumentation = "custom")
   )
   
   server <- function(input, output) {
     otel::end_span(.shiny_startup_span)
   
     output$distPlot <- renderPlot({
       x <- faithful$waiting
       bins <- seq(min(x), max(x), length.out = input$bins + 1)
       hist(x, breaks = bins, col = "steelblue", border = "white",
            main = "Old Faithful waiting times",
            xlab = "Waiting time (min)")
     })
   }
   
   shinyApp(ui = ui, server = server)

   
3. posit-shiny-automation

   added

   Priority: LowLow-impact bug, docs polish, papercut, or unclear low-severity request.Low-impact bug, docs polish, papercut, or unclear low-severity request.

   on May 14, 2026