Pinning a MID Server to a specific version

  • Release version: Yokohama
  • Updated January 30, 2025
  • 2 minutes to read
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    Summary of Pinning a MID Server to a specific version

    This document explains how ServiceNow customers can pin MID Servers to specific versions either globally or individually. Pinning controls which MID Server version is used in your environment, but it is generally recommended to allow the instance to manage MID Server versions automatically to avoid version mismatches and broken functionality.

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    Version Control Properties

    • mid.buildstamp: This system property specifies the MID Server version based on the build date and time (format: mm-dd-yyyy-hhmm). MID Servers check this property hourly to determine their version. It resets to the instance default upon restart or upgrade, so any manual changes are lost. This property is hidden by default and should not be manually configured.
    • mid.version.override: This property enables pinning all MID Servers in your environment to a single specific version, disabling automatic upgrades. It is not visible by default and must be added manually to the System Property table. When set, MID Servers prioritize this version over the mid.buildstamp property. This override persists across instance restarts but is cleared during upgrades, which then revert MID Servers back to the default version.

    Version Control Configuration Parameter

    To pin individual MID Servers to specific versions, you can set the mid.pinned.version parameter in the MID Server's config.xml file. The value uses the format <version>-mm-dd-yyyy. This parameter overrides global system properties for that MID Server and is checked every 20 minutes or upon MID Server restart. Importantly, this setting is not affected by instance upgrades, allowing persistent version pinning for specific MID Servers.

    Practical Considerations for ServiceNow Customers

    • Do not pin MID Servers unless absolutely necessary to avoid potential version conflicts and functionality issues.
    • If pinning all MID Servers, use the mid.version.override system property carefully, understanding it disables automatic upgrades and resets on instance upgrades.
    • For selective pinning, use the mid.pinned.version parameter in the MID Server configuration to maintain control over individual MID Server versions independently from the instance upgrade cycle.
    • Allow the instance to manage MID Server versions by default for smoother operation and compatibility.

    You can pin all the MID Servers in your environment to a specific version by setting a system property, or you can configure specific versions for individual MID Servers.

    Note:
    Under most circumstances, do not pin the MID Server to a specific version. Pinning the MID server can make it out of sync with the instance, and lead to broken functionality. Instead, let the instance determine which MID Server version to use.

    Version control properties

    These system properties control the version for all MID Servers:
    • mid.buildstamp: Identifies the MID Server version with an identifier based on the date of the build. This property uses the format of mm-dd-yyyy-hhmm. The MID Server checks for version information hourly. If no override version is configured, the MID Server looks at the mid.buildstamp property for the version to use. This property resets itself to the default version (the version that matches your instance version) when the instance is restarted or upgraded, so any user changes are lost at that time. The system appends the release name and patch information to the date and time format.
      Warning:
      This property is not visible by default and should not be configured.
    • mid.version.override: Sets an override condition for the current version for all MID Servers in your environment. This action pins the MID Servers to a single version and disables the automatic upgrade feature. This property is not visible in the base system and must be added to the System Property [sys_properties] table when it is set. For details, see Add a system property.
      When the MID Servers check the version each hour, they look at the mid.version.override property first. If this property is empty, the MID Servers get their version information from the mid.buildstamp property. If an override version is configured, the MID Servers use this value and ignore the version information in the mid.buildstamp property. This override value remains when the instance is restarted and is passed to the MID Servers.
      Important:
      The value in the mid.version.override property is cleared during an upgrade, which forces the MID Server to reset itself to the version in the mid.buildstamp property.

    Version control configuration parameter

    To pin specific MID Servers on a desired version, set the mid.pinned.version parameter with the name of that version in the config.xml file of each MID Server. Use the format <version>-mm-dd-yyyy. This setting overrides the property setting for the pinned MID Server version. The MID Server version is checked every 20 minutes or whenever the MID Server restarts, at which point the pinned version is applied. For instructions, see Add a MID Server parameter.
    Note:
    The value set in this parameter is not affected by an upgrade.