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Handle Function Processing Errors

The common types of exceptions that can occur when evaluating MATLAB® functions include:

  • HTTP errors — Handled using the Python® httplib.HTTPException exception. Common reasons for HTTP errors include:

    • Using an incorrect archive name

    • Using an incorrect function name

    • Timing out before the function finishes evaluating

  • MATLAB Runtime errors — Handled using the matlab.mpsexception.MATLABException exception. Occurs when the MATLAB Runtime generates an error while evaluating a function.

Your client code should handle these errors gracefully.

HTTP Errors

If your client code experiences any issues when sending data to or receiving data from a server instance, an httplib.HTTPException exception is raised. A common cause for an HTTP error is a name mismatch between deployed artifacts on the server and the functions called in the client.

For example, deploying the function mutate() in the archive mutations the following results in an error because the server instance would not be able to resolve the name of the archive.

import httplib
import matlab
from production_server import client

def main()
  my_client = client.MWHttpClient("http://localhost:9190")

  try:
    result = my_client.mutation.mutate("blue",10,12)
    ...
  except httplib.HTTPException as e:
    print e

If you deploy the function mutate() in the archive mutations, the following results in an error because the server instance would not be able to resolve the name of the function.

import httplib
import matlab
from production_server import client

def main()
  my_client = client.MWHttpClient("http://localhost:9190")

  try:
    result = my_client.mutations.mutator("blue",10,12)
    ...
  except httplib.HTTPException as e:
    print e

MATLAB Runtime Errors

If an error occurs while the MATLAB Runtime is evaluating a function, a matlab.mpsexception.MATLABException exception is raised. The exception contains the following:

  • ml_error_message — Error message returned by the MATLAB Runtime

  • ml_error_identifier — MATLAB error ID

  • ml_error_stackMATLAB Runtime stack

This function catches any MATLAB Runtime errors and prints them to the console.

from matlab.production_server import client
from matlab.production_server import mpsexceptions
import sys

def main(size):

  my_client = client.MWHttpClient('http://localhost:9190')
  try:
    data = my_client.magic.mymagic(size)
    print data
  except mpsexceptions.MATLABException as e:
    print 'MATLAB Error: ',e

  my_client.close()