Understanding Two-Digit and Three-Digit MEPs

Understanding the differences between the MEP directories on package.mapr.com can help you prevent versioning issues.

To install or update a MapR Expansion Pack (MEP), either manually or by using the MapR Installer, you must first choose a MEP version. The MEP version that you choose has a corresponding subdirectory on package.mapr.com from which the ecosystem packages are retrieved.

For each released MEP, the package.mapr.com/releases/MEP/ directory includes both two-digit and three-digit subdirectories:

The following table compares the two-digit and three-digit subdirectories and describes how they are used.

MEP Subdirectory Example Continuously Updated? Description
2-digit MEP-3.0/ Yes Subdirectories using two digits (for example, MEP-3.0) contain the latest MEP and patches and are continuously updated. For example, if you select MEP 3.0 when using the MapR Installer, the installer installs or upgrades your cluster with the packages from the most current version of MEP 3.0.x. If the most current version is MEP 3.0.1, MEP 3.0.1 is installed. If the most current version is MEP 3.0.2, MEP 3.0.2 is installed, and so on.

If you later decide to make changes to the cluster, the MapR Installer applies the packages from the most current version, which can be different from the version you installed originally.

Two-digit MEP version numbers make new patches available automatically without the need for system reconfiguration.

3-digit MEP-3.0.0/ No Subdirectories using three digits contain a fixed MEP version, including patches, and are not continuously updated. For example, if you select MEP 3.0.0 when using the MapR Installer, the installer uses the packages from the MEP-3.0.0 subdirectory and continues to use the MEP-3.0.0 subdirectory until you change the specified MEP version.

Three-digit MEP version numbers ensure that your cluster uses only the specified MEP version. They are best for users who install MapR software manually and do not require automatic updates.

MapR Installer Use of Two-Digit and Three-Digit MEPs

MapR Installer version 1.5 automatically uses two-digit MEPs. MapR Installer versions 1.6 and later use three-digit MEP versions and do not allow you to select two-digit MEPs.

Upgrades from MapR Installer 1.5 to 1.6 or later

If you upgrade the MapR Installer from version 1.5 to a later version, you see both two-digit and three-digit MEPs in the MEP dropdown list for an Incremental Install. The two-digit MEPs continue to operate as they did previously, installing the latest three-digit MEP with the same first two digits. The three-digit MEPs operate as described earlier on this page. MapR Installer version 1.7 displays and supports only three-digit MEPs.
Note: If your cluster uses two-digit MEPs, MapR recommends that you upgrade to three-digit MEPs as soon as it is convenient to do so. Doing so enables you to use new features such as the "Extend Cluster" feature without introducing MEP version inconsistencies. You can upgrade by performing an Incremental Install and selecting a three-digit MEP.