Shiny fileInput Issues/Tests on Azure ML Compute Instance

Background

• There might be unannounced changes on Azure ML compute instance during May/June 2022

• Initially the fileInput function (from shiny) stopped working

  • I only tested xlsx, xls and csv files. There might be more issues with other filetypes
  • the SHA uploaded of the uploaded files will be different.

• Then Azure ML compute instance would just stopped provisioning RStudio

  • As of today (29-Jun-2022),
    • Azure docs doesn't mention this or the rational behind this.
    • the custom application approach of add RStudio doesn't work e.g. it can't access the folders/files on the compute instance.

• I have created this app to test/check what actually happen to the uploaded file

  • Specifically I look at these properties of the uploaded file:
    • location
    • SHA
    • Estimated file encoding
    • if possible render table output

Shiny Upload App

• Clone the repo to your machine/env.

• Run the app as standard shiny app

• I have used the iris dataset as test data in different formats, these are located in the /DATA

• I have tested in various environments, so far it is working fine except in Azure ML Compute Instance

• For example, if I run it locally:

  • XLSX
    • 
  • XLS
    • 
  • CSV
    • 
  • The SHA of the uploaded files matched and all table outputs worked.

Azure ML Compute Instance specific issues

• If you run the same app on Azure ML compute instance, you will see the SHAs are different.
  • XLSX
    • 
  • XLS
    • 
  • CSV
    • 
  • All SHA of the uploaded files are different, but ASCII based files (e.g. CSV) still works.
  • NOTE this used to work fine on Azure until ~ mid-May 2022 (I think)

File encoding for reference

• These are the estimated encoding of the raw test data

           iris.csv iris.xls       iris.xlsx
encoding   "ASCII"  "windows-1250" "ASCII"  
confidence 1        0.22           1        

• Source code

sapply(list.files("DATA/"), function(x) {
  readr::guess_encoding(paste0("DATA/",x))
  })

Repo Structure

.
├── [   0]  DATA ** <- Sample Data**
│   ├── [3.8K]  iris.csv
│   ├── [ 36K]  iris.xls
│   └── [9.4K]  iris.xlsx
├── [   0]  R
│   └── [1.8K]  app.R
└── [ 730]  README.md