When upgrading your JVM version or installation, care should be taken as changing the JVM will momentarily remove and replace required libraries and components which may upset the operation of Tungsten Cluster while the upgrade or update takes place.
For this reason, JVM updates or changes must be treated as an OS upgrade or event, requiring a Primary switch and controlled stopping of services during the update process.
A sample sequence for this in a 3-node cluster is described below:
| Step | Description | Command | host1 | host2 | host3 |
|---|---|---|---|---|---|
| 1 | Initial state | Primary | Replica | Replica | |
| 2 |
Stop all services on
host2.
| stopall | Primary | Stopped | Replica |
| 3 | Update the JVM | Primary | Stopped | Replica | |
| 4 |
Start all services on
host2 Replica.
| startall | Primary | Replica | Replica |
| 5 |
Stop all services on
host3.
| stopall | Primary | Replica | Stopped |
| 6 | Update the JVM | Primary | Replica | Stopped | |
| 7 |
Start all services on
host3 Replica.
| startall | Primary | Replica | Replica |
| 8 |
Stop all services on
host1.
| stopall | Stopped | Replica | Replica |
| 9 | Update the JVM | Stopped | Replica | Replica | |
| 10 |
Start all services on
host1 Primary.
| startall | Primary | Replica | Replica |
The status of all services on all hosts should be checked to ensure they are running and operating as normal once the update has been completed.