Answers.Body: <p>At the beginning of an update, one of the things that Craft does is set to the <code>maintenance</code> column in the <code>craft_info</code> in the database to <code>1</code> to indicate that it's in maintenance mode.</p>
  
  <p>One of the other things it does at the beginning of an update is to check and see if that column is <em>already</em> set to one.</p>
  
  <p>That can happen under two, maybe three circumstances.</p>
  
  <ol>
  <li><p>Someone else is updating the site at nearly the exact same time, but was slightly faster than you to do so.</p></li>
  <li><p>There was a a previous update attempted, but some fatal error happened and that column never got set back to <code>0</code> properly.</p></li>
  <li><p>Some plugin is (incorrectly) setting that column to <code>1</code> for its own purposes.</p></li>
  </ol>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-04-13T06:56:51.180Z
Answers.Text: Thank you, Brad - I will keep an eye out on that particular setting in the db next time it occurs. Will this be logged also?
Answers.UserDisplayName: Nutmeg
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-04-13T07:15:10.730Z
Answers.Text: There will be update logging information in `craft/storage/logs`, yes.
Answers.UserDisplayName: Brad Bell
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-04-13T04:27:40.210Z
Answers.LastActivityDate: 2018-04-13T04:27:40.210Z
Answers.UserDisplayName: Brad Bell
Body: <p>Running a number of development sites on MAMP Pro and repeatedly receive this alert when attempting to update. Updates are consciously being performed nonsimultaneously, but that does not seem to prevent the system alert. What triggers this?</p>
  
  <pre><code>It looks like someone is currently performing a system update.
  
  Only continue if you’re sure that’s not the case.
  </code></pre>
  
Tags: <craft3><error-handling>
Title: Multiple dev sites
ThreadText: # Multiple dev sites
  
  (Asked by: username_0 on 2018-04-12)
  
  Running a number of development sites on MAMP Pro and repeatedly receive this alert when attempting to update. Updates are consciously being performed nonsimultaneously, but that does not seem to prevent the system alert. What triggers this?
  
  ```
  It looks like someone is currently performing a system update.
  
  Only continue if you’re sure that’s not the case.
  
  ```
  
  **Tags:** craft3, error-handling
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2018-04-13. Score: 0 | Accepted answer
  
  At the beginning of an update, one of the things that Craft does is set to the `maintenance` column in the `craft_info` in the database to `1` to indicate that it's in maintenance mode.
  
  One of the other things it does at the beginning of an update is to check and see if that column is *already* set to one.
  
  That can happen under two, maybe three circumstances.
  
  1. Someone else is updating the site at nearly the exact same time, but was slightly faster than you to do so.
  2. There was a a previous update attempted, but some fatal error happened and that column never got set back to `0` properly.
  3. Some plugin is (incorrectly) setting that column to `1` for its own purposes.
  
  > **Comments:**
  > **username_0**: Thank you, username_1 - I will keep an eye out on that particular setting in the db next time it occurs. Will this be logged also?  
  > **username_1**: There will be update logging information in `craft/storage/logs`, yes.  
  
  ---
  
  