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/shunning 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 |
Shun Replica host2
| datasource host2 shun | Primary | Shunned | Replica |
| 3 |
Stop all services on
host2.
| stopall | Primary | Stopped | Replica |
| 4 | Update the JVM | Primary | Stopped | Replica | |
| 5 |
Start all services on
host2 Replica.
| startall | Primary | Replica | Replica |
| 6 | Recover Replica back | datasource host2 recover | Primary | Replica | Replica |
| 7 |
Ensure the Replica ( host2 )
has caught up
| ls | Primary | Replica | Replica |
| 8 |
Shun Replica host3
| datasource host3 shun | Primary | Replica | Shunned |
| 9 |
Stop all services on
host3.
| stopall | Primary | Replica | Stopped |
| 10 | Update the JVM | Primary | Replica | Stopped | |
| 11 |
Start all services on
host3 Replica.
| startall | Primary | Replica | Replica |
| 12 | Recover Replica back | datasource host3 recover | Primary | Replica | Replica |
| 13 |
Ensure the Replica ( host3 )
has caught up
| ls | Primary | Replica | Replica |
| 14 |
Switch Primary to host2
| switch to host2 | Replica | Primary | Replica |
| 15 |
Shun host1
| datasource host1 shun | Shunned | Primary | Replica |
| 16 |
Stop all services on
host1.
| stopall | Stopped | Primary | Replica |
| 17 | Update the JVM | Stopped | Primary | Replica | |
| 18 |
Start all services on
host1 Replica.
| startall | Replica | Primary | Replica |
| 19 |
Recover host1 back
| datasource host1 recover | Replica | Primary | Replica |
| 20 |
Ensure the Replica ( host1 )
has caught up
| ls | Replica | Primary | Replica |
| 21 |
Switch Primary back to
host1
| switch to host1 | Primary | Replica | Replica |