Managing Software Installation
A major function of Cloudera Manager is to install CDH and managed service software in your cluster. Cloudera Manager supports two software distribution formats: packages and parcels.
A package is a binary distribution format that contains compiled code and meta-information such as a package description, version, and dependencies. Package management systems evaluate this meta-information to allow package searches, perform upgrades to a newer version, and ensure that all dependencies of a package are fulfilled. Cloudera Manager uses the native "system package manager" for each supported OS.
A parcel is a binary distribution format containing the program files, along with additional metadata used by Cloudera Manager. There are a few notable
differences between parcels and packages:
- Parcels are self-contained and installed in a versioned directory, which means that multiple versions of a given parcel can be installed side-by-side. You can then designate one of these installed versions as the active one. With packages, only one package can be installed at a time so there's no distinction between what's installed and what's active.
- Parcels can be installed at any location in the filesystem and by default are installed in /opt/cloudera/parcels. In contrast, packages are installed in /usr/lib.
- Parcel handling automatically downloads, distributes, and activates the correct parcel for the operating system running on each host in the cluster. All CDH and Cloudera Manager hosts that make up a logical cluster need to run on the same major OS release to be covered by Cloudera Support.
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