In multiple datacenter clusters, upgrade every node in one datacenter before upgrading another datacenter.

Upgrade the seed nodes within a datacenter first.

DSE Analytics datacenters

Transactional/DSE Graph datacenters

DSE Search nodes or datacenters

Upgrade to the latest patch release on your current version. Fixes included in the latest patch release can simplify the upgrade process.

bin/dse -v
current_dse_version

Familiarize yourself with the changes and features in the new release:

Before upgrading, be sure that each node has adequate free disk space.

sudo du -sh /var/lib/cassandra/data/
3.9G	/var/lib/cassandra/data/

sudo df -hT /
Filesystem     Type  Size  Used Avail Use% Mounted on
/dev/sda1      ext4   59G   16G   41G  28% /

Replace ITriggers and custom interfaces.

Support for Thrift-compatible tables (COMPACT STORAGE) is dropped. Before upgrading, migrate all non-system tables that have COMPACT STORAGE to CQL table format:

cqlsh -e 'DESCRIBE FULL SCHEMA;' > schema_file

cat schema_file | while read -d $';\n' line ; do
  if echo "$line"|grep 'COMPACT STORAGE' 2>&1 > /dev/null ; then
    TBL="`echo $line|sed -e 's|^CREATE TABLE \([^ ]*\) .*$|\1|'`"
    if echo "$TBL"|egrep -v '^system' 2>&1 > /dev/null; then
      echo "ALTER TABLE $TBL DROP COMPACT STORAGE;" >> schema-drop-list
    fi
  fi
done

cqlsh -f schema-drop-list

Upgrade the SSTables on each node to ensure that all SSTables are on the current version:

nodetool upgradesstables

Ensure that keyspace replication factors are correct for your environment:

cqlsh --execute "DESCRIBE KEYSPACE keyspace-name;" | grep "replication"
CREATE KEYSPACE keyspace-name WITH replication = {'class': 'NetworkTopologyStrategy, 'replication_factor': '3'}  AND durable_writes = true;

Verify the Java runtime version and upgrade to the recommended version.

java -version
openjdk version "1.8.0_222"
OpenJDK Runtime Environment (build 1.8.0_222-8u222-b10-1ubuntu1~18.04.1-b10)
OpenJDK 64-Bit Server VM (build 25.222-b10, mixed mode)

Run nodetool repair to ensure that data on each replica is consistent with data on other nodes:

nodetool repair -pr

Install the libaio package for optimal performance.

sudo yum install libaio

sudo apt-get install libaio1

Back up any customized configuration files because they may be overwritten with default values during installation of the new version.

Flush the commit log of the current installation:

nodetool drain

Stop the node:

Use the appropriate method to install the new product version on a supported platform:

To configure the new version:

When upgrading DSE to versions earlier than 5.1.16, 6.0.8, or 6.7.4 inclusive, if any tables are using DSE Tiered Storage, remove all txn_compaction log files from second-level tiers and lower. For example, given the following dse.yaml configuration, remove txn_compaction log files from /mnt2 and /mnt3 directories:

tiered_storage_options:
    strategy1:
        tiers:
            - paths:
                - /mnt1
            - paths:
                - /mnt2
            - paths:
                - /mnt3

find /mnt2 -name "*_txn_compaction_*.log" -type f -delete &&
find /mnt3 -name "*_txn_compaction_*.log" -type f -delete

Remove any previously installed JTS JAR files from the CLASSPATHS in your DSE installation. JTS (Java Topology Suite) is distributed with DSE 6.7.

Start the node.

Verify that the upgraded datacenter names match the datacenter names in the keyspace schema definition:

Review the logs for warnings, errors, and exceptions:

grep -w 'WARNING\|ERROR\|exception' /var/log/cassandra/*.log

Repeat the upgrade process on each node in the cluster following the recommended order.

After the entire cluster upgrade is complete: upgrade the SSTables on one node at a time or, when using racks, one rack at a time.

nodetool upgradesstables

If you use the OpsCenter Repair Service, turn on the Repair Service (6.8).

If you encounter serialization-header errors, stop the node and repair them using the sstablescrub -e option:

sstablescrub -e fix-only keyspace table

DSE 6.7 introduces, and enables by default, the DSE Metrics Collector, a diagnostics information aggregator used to help facilitate DSE problem resolution. For more information on the DSE Metrics Collector, or to disable metrics collection, see DataStax Enterprise Metrics Collector (6.8).

Spark Jobserver uses DSE custom version 8.0.4.45. Ensure that applications use the compatible Spark Jobserver API from the DataStax repository.

Install yum-versionlock (one-time operation):

sudo yum install yum-versionlock

Lock the current DSE version:

sudo yum versionlock dse-*