Replicated Regions

Introduction

This is a simple example that demonstrates putting values into a VMware GemFire replicated region, checking the size, and retrieving the values. It assumes you have installed JDK11 and GemFire. Replicated regions store identical copies of data on each cache member, ensuring high availability and providing the highest performance for read-intensive data sets across the entire distributed system.

Steps

1. From the gemfire-examples/replicated directory, build the example and run unit tests

$ ../gradlew build

2. Next start the locator and two servers

$ gfsh run --file=scripts/start.gfsh

3. Run the example to create entries in the region

 $ ../gradlew run

4. Kill one of the servers

$ gfsh -e "connect --locator=127.0.0.1[10334]" -e "stop server --name=server1"

5. Run a gfsh query, and notice that all the entries are still available due to replication

$ gfsh -e "connect --locator=127.0.0.1[10334]" -e "query --query='select e.key from /example-region.entries e'"

6. Shut down the system:

$ gfsh run --file=scripts/stop.gfsh