Upgrading DataStax Enterprise 5.1 using the DataStax installer

These steps show how to upgrade to versions of DataStax Enterprise (DSE) up to 5.1 using the GUI installer.

The DataStax installer is removed starting with DSE 6.0.

The DataStax installer upgrades DataStax Enterprise and automatically performs many upgrade tasks:

Drains the currently running node.
Preserves the configuration files and places them in a backup directory.
Removes previously installed packages.
Updates the cassandra.yaml and dse.yaml configuration files with new entries.

Prerequisites

To upgrade to the latest version of DataStax Enterprise using the DataStax Installer, ensure the following requirements are met:

DataStax Enterprise 5.0 for upgrading to 5.1

Read and understand these instructions before upgrading. Carefully reviewing the planning and upgrade instructions can prevent errors and data loss.

DataStax Enterprise and Apache Cassandra™ Configuration Files

cassandra.yaml

The location of the cassandra.yaml file depends on the type of installation:

Package installations + Installer-Services installations (DSE 4.5 to 5.1)

/etc/cassandra/cassandra.yaml

Tarball installations + Installer-No Services installations (DSE 4.5 to 5.1)

<install_location>/conf/cassandra.yaml

Default DataStax Enterprise installer backup locations (DSE 4.5 to 5.1)

The backup directory name is based on date and time. For example: 20170212_221550

Table 1. Default Location of Configuration Files Dependent On Installation Type
Installer-Services	`/usr/share/dse/backups/backup_file_dir`
Installer-No Services	`install_location/backups/backup_file_dir`

dse.yaml

The location of the dse.yaml file depends on the type of installation:

Package installations

/etc/dse/dse.yaml

Tarball installations

<installation_location>/resources/dse/conf/dse.yaml

Upgrading Linux installations using the DataStax Installer

Familiarize yourself with the changes and features in the release:
- DataStax Enterprise release notes for 5.1.
- General upgrade advice and Cassandra features in NEWS.txt. If you are upgrading from an earlier version, read NEWS.txt all the way back to your current version.
- Cassandra changes in CHANGES.txt.
Upgrade to the /en/upgrade/doc/upgrade/datastax_enterprise/upgdDseMinorTOC.html[latest patch release] on your current version. Fixes included in the latest patch release can simplify the upgrade process.

Get the current DSE version:
```
bin/dse -v
current\_dse\_version
```
Verify the Java runtime version and upgrade to the recommended version.
```
java -version
```
- DataStax Enterprise 5.0 and later
The JDK is recommended for development and production systems, and provides useful troubleshooting tools that are not in the JRE, such as jstack, jmap, jps, and jstat.

Download the installer for your computer from the DataStax downloads page or use the following command:

curl --user dsa\_email\_address:password -O https://downloads.datastax.com/enterprise/DataStaxEnterprise-5.1.x-linux-x64-installer.run

For example, alice can run this command to download DSE 5.1.0:

curl --user alice@email.com:password -O https://downloads.datastax.com/enterprise/DataStaxEnterprise-5.1.0-linux-x64-installer.run

From the directory where you downloaded the install file, make it executable and run it using the sudo command.

$ chmod +x DataStaxEnterprise-version\_number-linux-x64-installer.run ## Changes permission to executable
$ sudo ./DataStaxEnterprise-version\_number-linux-x64-installer.run

Follow the instructions in the setup wizard. For a detailed description of the settings in the wizard, see the installation instructions in 5.1
When upgrading DSE to versions earlier than 5.1.16 , 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
```
The following example removes the files using the find command:
```
find /mnt2 -name "*_txn_compaction_*.log" -type f -delete &&
find /mnt3 -name "*_txn_compaction_*.log" -type f -delete
```
Failure to complete this step may result in data loss.

Start DataStax Enterprise:

sudo service dse start ## Starts the DataStax Enterprise server

(DataStax Enterprise 4.7 and 4.8 only) Start the DataStax Agent:
```
sudo service datastax-agent start
```
For DataStax Enterprise 5.1, see the OpsCenter 6.1 documentation.
Verify that DataStax Enterprise is running:
```
nodetool status
```