How to Deploy model using plumber API from CMD line R?

Question

New to using plumber API, trying to deploy R model, I have saved the R Model and a test data (OneRecord). Ran the plumber API from CMD line, 127.0.0.1:8000 returns Error "{"error":["500 - Internal server error"]}" and the terminal shows an error of "simpleError in if (opts$show.learner.output) identity else capture.output: argument is of length zero"

My R Code

#plumb_test.R
library(plumber)
#Simple msg command
#* @apiTitle Plumber Example API

#* Echo back the input
#* @param msg The message to echo
#* @get /echo
function(msg=""){
  list(msg = paste0("The message is: '", msg, "'"))
}

#My Model
#* @get /run
function(){
  rf_prediction <- predict(readRDS("rf_unwrap.rds"), newdata = as.data.frame(readRDS("Test_data.Rds")))
  rf_prediction$data
}

R Code for plumber run

library(plumber)
pr <- plumb("plumb_test.R")
pr$run(port=8000)

msg working properly

http://127.0.0.1:8000/echo?msg=hellohru

returns me

{"msg":["The message is: 'hellohru'"]}

But my model returns

{"error":["500 - Internal server error"]}
in the terminal I am getting
> pr$run(port=8000)
Starting server to listen on port 8000
<simpleError in if (opts$show.learner.output) identity else capture.output: argument is of length zero>

I am running from windows cmd line as follows

C:\R\R-3.5.2\bin>r -f plumb_run.R

All the files were in bin folder (model, test data, plumb R scripts)

Expecting the output of prediction, not sure what the error means.

When I run from R Console, it is working, getting prediction output both in console and swagger UI — hanzgs, May 17 '19 at 00:14

score 1 · Accepted Answer · answered May 17 '19 at 01:57

loading mlr library along with plumber and using print in the function, everything worked

library(plumber)
library(mlr)
#My Model
#* @get /run
function(){
  print(predict(readRDS("rf_unwrap.rds"), newdata = as.data.frame(readRDS("Test_data.Rds")))$data)
}

How to Deploy model using plumber API from CMD line R?

1 Answers1