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.
geode-examples/overflow to be the current working directory. Each step in this example specifies paths relative to that directory.
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.
Shut down the cluster
$ gfsh run --file=scripts/stop.gfsh
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.