Copied to clipboard

Flag this post as spam?

This post will be reported to the moderators as potential spam to be looked at

  • Michael Taylor 5 posts 75 karma points
    Jun 06, 2019 @ 12:25
    Michael Taylor

    VBCSCompiler has high CPU usage

    Hi All,

    I'm hoping someone can help me with this one. I haven't successfully found any information about this so far.

    I have recently set my Umbraco website live which currently contains only a few nodes with simple content. There are 4 root nodes, which are served on different domains.

    I've noticed that once I sign in to the Umbraco backend, each simple content update often takes a while to save and refreshing the website itself takes long.

    While this is happening, the task manager on the server - viewed through remote desktop connecton - shows that VBCSCompiler uses a lot of CPU and sometimes shoots the usage up to 99% for up to a minute at a time.

    When I refresh multiple domains at once, VBCSCompiler appears once for each website, both using high CPU.

    I host other websites on this server and obviously can't have this process using so much CPU as content across multiple websites is updated daily by multiple editors.

    Thank you for any help you can offer.

    Kind regards,


  • SteveV 43 posts 207 karma points
    Jun 06, 2019 @ 19:17

    Easiest thing to check is if there is an update for the compiler. Is the Microsoft.CodeDom.Providers.DotNetCompilerPlatform Nuget package up to date? It's at version 2.0.1 right now.

  • Michael Taylor 5 posts 75 karma points
    Jun 07, 2019 @ 07:55
    Michael Taylor

    Hi SteveV,

    Thank you for the response.

    1. I created the website project manually, so unfortunately there is no package meta data of what's installed for the site :/. I'll try find out if there's a way I can create a packages file from installed packages in a site ;).

    2. I finally resolved the issue by following advice by Dave Woestenborghs at the following link:

    Essentially, I turned off real-time compiling on the site by changing the Models Builder mode from "PureLive" to "Dll" and then rebuilding the models on the site. The Roslyn compiler is only used to compile scripts as the site is being used.

    Thanks again for the response.

    Enjoy a great weekend ahead,


Please Sign in or register to post replies

Write your reply to: