[This is preliminary documentation and subject to change]

# Edit-While-Running Scenario 8

This scenario illustrates how edit-while-running works under the following conditions:

- MetaBase.xml contains a missing XML end tag and therefore cannot be successfully parsed.

What you will learn:

- How IIS behaves when MetaBase.xml is saved and cannot be parsed.
- How IIS names error files in the history folder.

Note For the purpose of this scenario, it is not important to know the values contained within the metabase; only the version number of the metabase files are important.

Step 1:
An administrator opens MetaBase.xml using Notepad, inadvertently deletes an XML end tag, and saves MetaBase.xml.

When MetaBase.xml is edited and saved, the following happens:

1. IIS receives a file change notification that the MetaBase.xml file has been saved.
2. IIS looks within the MetaBase.xml file for the HistoryMajorVersionNumber value.
3. IIS looks within the history folder for the corresponding history file. The corresponding history file is the file with the same HistoryMajorVersionNumber value that was found in step 2, with the highest minor version number.
4. IIS attempts to parse MetaBase.xml and determines that there is a fatal error, which is the missing XML end tag. IIS copies MetaBase.xml into the history folder and renames the file to MetaBaseError_0000000002.xml.
5. IIS sends an error to the event log.
6. The in-memory metabase is saved to disk, and a new history file is created.

In this case, the in-memory metabase is written to disk to overwrite the non valid MetaBase.xml file. Changes that were made to the non valid MetaBase.xml file are not applied to the in-memory metabase.

phrase 1, phrase 2, phrase 3

© 1997-2001 Microsoft Corporation. All rights reserved.