This examples demonstrates how to use Geode's Overflow to disk.

In this example, a server hosts a partitioned region that stores strings. The example shows entry values being overflowed to disk and removed from memory.

This example assumes that Geode is installed.

1. Set directory geode-examples/overflow to be the current working directory. Each step in this example specifies paths relative to that directory.

2. Run a script that starts a locator and two servers. The script then creates the example-region region and puts 4 entries.

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

Note that both the region size and totalEntriesOnlyOnDisk are 0 before we put any entries.

3. Shut down the cluster

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

4. In the output of the second show metrics --region=example-region command, notice the line

diskstore | totalEntriesOnlyOnDisk | 2

This shows that 2 values have been overflowed to disk and are no longer in memory. Notice that the size from the second describe region --name=example-region is still 4

Region | size | 4

Because all the keys remain in memory. The entries are still accessible.