Upgrading or Updating your JVM

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	Shunned	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	Shunned
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	Shunned	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