Security Compliance

WSUS synchronization fails with HTTP Error 503

This article addresses an error when initializing an update task with WSUS. Error: HTTP Error 503. The service is unavailable.

First published date

11/29/2018 10:49 PM

Last published date

11/7/2022 2:05 AM

Overview

When you initialize an update task with WSUS, the following error appears:

HTTP Error 503. The service is unavailable.

The error may also appear when running a WSUS inventory task. The inventory may or may not be complete or is partially complete. 
 

Product section

Patch Manager

Cause

  • The WsusPool Application Pool in IIS is in a Stopped state. 
  • The Private Memory Limit (KB) for the Application Pool is set to the default value of 1843200 KB.

Resolution

Consult with your systems administrator before you perform this procedure.
 

  1. Open the IIS Manager.
  2. Expand your site to find Application Pools.
  3. In the center pane, select WsusPool.
  4. In the Actions pane, click Start.
  5. Increase the Private Memory Limit to 4GB (4000000 KB)- Make sure the server has enough memory to increase the memory setting in the IIS App Pool.  
    1. Stop the EminentWare Data Grid Server Service.
    2. In the center pane, select WsusPool.
    3. Under Edit Application Pool, click Advanced Settings.
    4. Manually set the Private Memory Limit to 4GB (4000000 KB).
  6. Restart the Application Pool.
  7. Start the EminentWare Data Grid Server Service.