DataStax Enterprise 2.2 Documentation
Preparing to Upgrade¶
You can upgrade from these releases to DataStax Enterprise 2.2.x:
- A previous release of DataStax Enterprise
- Cassandra 0.7.10, 0.8.10, or 1.0.x - 1.1.x
Critical Pre-upgrade Steps¶
Make a backup of the data by taking a snapshot of the node to be upgraded.
Save old installation keyspaces as described on the next page.
Run nodetool drain to flush the commit log of the old installation:
nodetool drain –h <hostname>
This step is mandatory. Failing to perform this step could result in data loss if a power failure occurs during the upgrade.
On Debian/Ubuntu, save the cassandra.yaml (and cassandra.topologies file if you use the PropertyFileSnitch) from the old installation in a safe location.
On RHEL-based platforms, RPM saves the file automatically during the upgrade process instead of overwriting it. RPM output looks something like this:
warning: /etc/cassandra/default.conf/cassandra.yaml saved as /etc/cassandra/default.conf/cassandra.yaml.rpmsave
On tarball platforms, you install the new release in a different location, so the old files are not overwritten.
Regardless of the platform, if you customized any other files, copy the files from the old installation to a safe location before performing an in-place upgrade that overwrites customized files.
Upgrade your installation according to these instructions:
- Upgrading from DataStax Community 1.0.x to DataStax Enterprise 2.2.x:
- Upgrading from DataStax Enterprise 1.x.x - 2.1.x to 2.2.x
- Upgrading from Other Versions of Cassandra or DataStax Community to DataStax Enterprise 2.2.x
Order of Upgrading Nodes¶
Observe the following order for upgrading nodes in a mixed workload cluster:
- Analytics: Jobtracker, remaining seeds, remaining task trackers
- Cassandra: Seeds, then remaining nodes
- Solr: Seeds, then remaining nodes
DSE Search/Solr nodes are upgraded last because they are more sensitive to schema disagreements.
Component Version Changes¶
The following component version changes and other major changes are included in DSE upgrades:
| Upgrade | Changes |
|---|---|
| DSE 1.0, 1.0.x, or 2.0.x | Cassandra updated to 1.1.5 |
| Hadoop updated to 1.0.2 | |
| Hive updated to 0.9.0 | |
| Pig updated to 0.9.2 | |
| Sqoop updated to 1.4.2 | |
| DataStax OpsCenter to 2.1 | |
| Mahout 0.6 added | |
| DSE 2.1 | Cassandra updated to 1.1.6 |
| Hadoop updated to 1.0.2 | |
| Hive updated to 0.9.0 | |
| Pig updated to 0.9.2 | |
| Sqoop updated to 1.4.2 | |
| DSE 2.2 | Cassandra updated to 1.1.9 |
For a complete list of Cassandra changes and new features, see https://github.com/apache/cassandra/blob/cassandra-1.1.9/CHANGES.txt.
Upgrading and Counter Columns¶
If you use counter columns, upgrading SSTables is highly recommended.
Tarball:
<install_location>/bin/nodetool -h upgradesstables
Package or AMI:
nodetool -h upgradesstables
Tapping NEWS.txt for Upgrading Information¶
NEWS.txt contains late-breaking information about upgrading from previous versions of Cassandra.
A NEWS.txt or a NEWS.txt archive is installed in the following locations:
Tarball: <install_location>/resources/cassandra
Package: /usr/share/doc/dse-libcassandra*
NEWS.txt is also posted on the Apache Cassandra project web site.
Unpack NEWS.txt.gz if it is an archive. For example:
cd /usr/share/doc/dse-libcassandra-2.2. sudo gunzip NEWS.txt.gz
Take at look at the information that is pertinent to your old version if there is any. For example, if you upgrade from some early versions, it might be necessary to upgrade SSTables.