Create Data Grid Cluster

With the Data Grid Operator installed, we can now create new Data Grid caches and services simply by creating custom resources.

Let's create our first Data Grid Cache using the OpenShift console. To get a feel for how the web console works, click this link to open the Overview in the OpenShift Console

The first screen you will see is the authentication screen. Enter your username and password and then log in:

• Username: admin
• Password: admin

You'll see the operator pod deployed:

Select the Developer View using the selector on the left and click Skip Tour to skip the new user introduction:

Create Data Grid Cache service

With the Operator installed, we can now start creating instances of Data Grid.

To do so, on the Developer View, click Add on the left, and select Operator Backed. This will allow you to create objects that installed Operators are looking for:

In this case, find and click on the Infinispan Cluster element:

And click Create.

Here you can configure your new Data Grid cluster (note we have not created any Caches yet within the cluster). There are many options described in the docs for security, users, and others. We'll keep it simple for this demo.

Change the name to datagrid-service and set the number of replicas to 2:

Finally, scroll to the bottom and click Create. You'll now see your new Data Grid cluster and its 2 replicas spin up. Click the following command to wait for it to finish:

oc rollout status -w statefulset/datagrid-service

NOTE: It may take a minute or so to fully spin up, as the container images must be downloaded the first time.

Now click on the box for datagrid-service to see its details:

Here you can see the two replicas running in 2 separate pods.

Access Data Grid Web Console

Data Grid has a built in single-port endpoint for all network access, including an administrative console for displaying cache configuration, statistics, and creating/changing data in the grid. The console is accessed over the same networking port as the grid itself. To get to it in this environment, we'll need to create a specialized Route to it. Click the following command to create this Route:

oc apply -f - << EOF
kind: Route
apiVersion: route.openshift.io/v1
metadata:
  name: my-dg
spec:
  to:
    kind: Service
    name: datagrid-service
    weight: 100
  port:
    targetPort: infinispan
  tls:
    termination: reencrypt
    insecureEdgeTerminationPolicy: Allow
  wildcardPolicy: None
EOF

You'll also need to get the default username/password to use when logging into the console. Retrieve them by clicking this command:

oc get secret datagrid-service-generated-secret -o jsonpath="{.data.identities\.yaml}" | base64 --decode

NOTE: These are default autogenerated credentials that can be disabled or reconfigured when for production use.

You should now be able to click here to connect to the Data Grid Console.

NOTE: You may need to accept browser warnings about self-signed insecure connections. We are not using real security certificates here for this demo!

Click Open The Console and login using the above credentials retrieved with the oc get secret command. You'll land on the home screen:

With the console you can create caches, perform adminstrative operations, and monitor your Data Grid clusters. We'll revisit this later to see effects of our exercises.

Let's save the password to a shell environment variable that we'll use later. Click this command to save it to the PASSWORD environment variable:

export PASSWORD=$(oc get secret datagrid-service-generated-secret -o jsonpath="{.data.identities\.yaml}" | base64 --decode | grep password | awk '{print $2}')

Congratulations you now have Data Grid up and running, but we haven't created any actual usable caches yet. We'll do that in the next step.

Types of Data Grid services

Data Grid has two types of services:

• Cache Service - if you want a volatile, low-latency data store with minimal configuration. Cache Service nodes automatically scale based on capacity pressure, synchronously distributes and replicates but are volatile and are reset if you reconfigure or delete the underlying Data Grid cluster.

• DataGrid Service - enables backing up data across global clusters using cross-site replication, can persist data in the grid, can issue queries across caches using the Data Grid Query API, and othert advanced features.

You might have noticed that in our first exercise we created the Cache service (the default type) in the upcoming exercises we will use other types.

Create cache

Let's create a simple cache in our cache service using the command line. Click on the following to create a new Cache custom resource (this could also be done via the web console):

oc apply -f - << EOF
apiVersion: infinispan.org/v2alpha1
kind: Cache
metadata:
  name: mycachedefinition
spec:
  clusterName: datagrid-service
  name: mycache
EOF

This creates a basic cache called mycache. There are many, many options for configuring caches but we'll just stick with the defaults for now.

You can see it in the Data Grid Admin console, you can see the new cache:

NOTE: You may need to reload the browser page to see it!

Adding data

Let's add some data! We'll use the Data Grid REST interface to add it. Click this command to add some random data to the mycache cache:

for i in {1..100} ; do
  curl -H 'Content-Type: text/plain' -k -u developer:$PASSWORD -X POST -d "myvalue$i" https://my-dg-dgdemo.[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com/rest/v2/caches/mycache/mykey$i
  echo "Added mykey$i:myvalue$i"
done

This will add 100 entries under keys mykey1, mykey2, ... with values myvalue1, myvalue2...

You can see the entries in the cache overview in the admin console:

You may need to click on the Entries tab.

You can view, edit and delete these entries graphically, through REST, or other protocols such as HotRod depending on your application and performance needs.

Access via REST

Red Hat Data Grid supports REST out of the box so you can invoke cache operations with these HTTP methods:

• GET: retrieves cache entries.
• POST: creates new cache entries under specified keys.
• DELETE: deletes cache entries.
• PUT: updates cache entries.

The URLs through which you invoke cache operations contain cache and key names. In addition, the invocation URL contains cache name and key name in its address. You'll see this encoding method in the example below.

Let's retrieve one of our cache entries. Click the following command:

curl -k -u developer:$PASSWORD https://my-dg-dgdemo.[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com/rest/v2/caches/mycache/mykey22

You should see its value returned myvalue22.

Now update it:

curl -H 'Content-Type: text/plain' -k -u developer:$PASSWORD -X PUT -d "mynewvalue22" https://my-dg-dgdemo.[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com/rest/v2/caches/mycache/mykey22

This updates the value to mynwvalue22. Retrieve it to verify:

curl -k -u developer:$PASSWORD https://my-dg-dgdemo.[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com/rest/v2/caches/mycache/mykey22

Now lets delete it:

curl -k -u developer:$PASSWORD -X DELETE https://my-dg-dgdemo.[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com/rest/v2/caches/mycache/mykey22

And retrieve it (it will fail with HTTP 404):

curl -i -k -u developer:$PASSWORD https://my-dg-dgdemo.[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com/rest/v2/caches/mycache/mykey22

This demonstrates basic RESTful access to Data Grid.

Viewing metrics

The admin console has built in metrics about each cache. Click the Metrics tab to see them:

You can also visit the Global Metrics screen to see more info about the Data Grid service as a whole, and confirm cluster status and the 2 replicas on the Cluster Membership screen.