How does mid server upgrade process work?
Below is the process that takes place when the mid server auto upgrades. As an example I am providing an example when Mid server is upgrading to Jakarta Patch 8
-AutoUpgrader run every one hour and it queries the mid build stamp on the instance to find the version of the mid. If it does not match, upgrade process kicks in.
-AutoUpgrader downloads https://install.service-now.com/glide/distribution/builds/package/mid-upgrade/2018/02/26/mid-upgrade.jakarta-05-03-2017__patch8-02-14-2018_02-26-2018_1106.universal.universal.zip to "E:\ServiceNow\MID_Server\agent\package\incoming\" directory
-The package is extracted to "C:\Windows\TEMP\1521847406788-0" directory (Directory name in temp will be randomly generated)
- The AutoUpgrader executes the C:\Windows\TEMP\1521847406788-0\mid-upgrade.jakarta-05-03-2017__patch8-02-14-2018_02-26-2018_1106.universal.universal\upgrade-wrapper\bin\glide-dist-upgrade.bat file to install and start the "ServiceNow Platform Distribution Upgrade" service. The service is ran as Local System user.
- The "ServiceNow Platform Distribution Upgrade" service stops MID Server process and started copying the "C:\Windows\TEMP\1521847406788-0\mid-upgrade.jakarta-05-03-2017__patch8-02-14-2018_02-26-2018_1106.universal.universal\upgrade-wrapper\bin\wrapper-windows-x86-64.exe" to "E:\ServiceNow\MID_Server\agent\bin\" directory. The file exists in target directory so it will be an overwrite.
-Once the mid server is properly upgraded, it shuts down the ""ServiceNow Platform Distribution Upgrade" and deletes the service.