Red Hat Data Grid 8 for Beginners

What Is Data Grid ?

Data Grid is a high-performance, distributed in-memory data store. It stores all info in memory rather than on Disk or file that makes it faster. It is built from Infinispan open-source Software project and is available to deploy as an embedded library or as a standalone server.

Data Grid 8.0 Server

Data Grid 8.0 Server is isolated from Red Hat JBoss Enterprise Application Platform (EAP) and is re-designed to be lightweight and more secure with much faster start times. It is designed to create a running Data Grid cluster within few minutes with negligible configuration changes.

8.0 release comes with features like Data Grid Operator, available from the Operator Hub on Red Hat OpenShift , it simplifies the process of creating and managing Data Grid clusters on OpenShift. 

It also has a powerful CLI to to access data and perform management operations . Alongside this CLI supports bash commands like cd and ls and provides clear examples of commands.

How to Quickly Set up Data Grid Server 8.0 and Learn the Basics?

Procedure to Download Data grid 8.0

1. Download the Red Hat Data Grid 8.0 server from the Get Data Grid for Development
2. Verify the  the integrity of your download using checksum.
3.  Run the md5sum or sha256sum command with the server download archive as the argument and compare the checksum value with the Data Grid Software Details page.

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$ md5sum redhat-datagrid-8.0.0-server.zip

f6d302b8cec812c604c45031cc30ee8d  redhat-datagrid-8.0.0-server.zip

5. Next for installation you can extract the Data Grid server archive to a directory on your host.For example:

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unzip redhat-datagrid-8.0.0-server.zip

The resulting directory is $RHDG_HOME.

• By default Data Grid servers running on the same network discover each other with the MPING protocol.

Data Grid server 8.0 provides a default configuration with clustering capabilities so your data is replicated across all nodes.

•  To start two Data Grid servers on the same host and verify the cluster view:

  • Install and run a new Data Grid server instance.

$ bin/server.sh


• Open a terminal in $RHDG_HOME ,copy the root directory to server2.

$ cp -r server server2


• Specify a port offset by passing -o and the location of the server2 root directory.

$ bin/server.sh -o 100 -s server2


• Verify the server logs for the following messages:

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13:00:51,137 INFO  (main) [org.infinispan.SERVER] ISPN080034: Server 'vasharma-57675' listening on http://127.0.0.1:11222

13:00:51,137 INFO  (main) [org.infinispan.SERVER] ISPN080001: Red Hat Data Grid Server 10.1.5.Final-redhat-00001 started in 4682ms

13:02:50,330 INFO  (jgroups-5,vasharma-57675) [org.infinispan.CLUSTER] ISPN000094: Received new cluster view for channel cluster: [vasharma-57675|1] (2) [vasharma-57675, vasharma-32704]

13:02:50,335 INFO  (jgroups-5,vasharma-57675) [org.infinispan.CLUSTER] ISPN100000: Node vasharma-32704 joined the cluster

13:02:50,831 INFO  (remote-thread--p3-t1) [org.infinispan.CLUSTER] [Context=org.infinispan.CLIENT_SERVER_TX_TABLE]ISPN100002: Starting rebalance with members [vasharma-57675, vasharma-32704], phase READ_OLD_WRITE_ALL, topology id 2

• To start Data Grid servers on two different host pass -b 192.168.xxx.x

./server.sh -s /location of the server root directory

-b 192.168.xxx.x


• Open 127.0.0.1:11222  in any browser to access the Data Grid console

Configuration Files of Data Grid 8

1. infinispan-local.xml
2.  infinispan.xml
3.  infinispan-xsite.xml

By default if not specified Data Grid 8.0 uses $RHDG_HOME/server/conf/infinispan.xml for configuration.

Configuration file can be specified while starting data grid server using -c option . 

For example : $ ./server.sh -c infinispan-local.xml.

Infinspan-local.xml can be used to start Data Grid in standalone mode..

Data Grid server 8.0 no longer provides a domain mode as in previous versions that were based on EAP. 

Data Grid 8.0  CLI

In order to connect to CLI  start the Data Grid CLI as follows:

1. Open a terminal in $ISPN_HOME.

2. Run the CLI.

$ bin/cli.sh [disconnected]>

• Run the connect command to connect to a Data Grid server on the default port of 11222:

[disconnected]> connect 

[hostname1@cluster//containers/default]>

• Specify the location of a Data Grid server. For example, connect to a local server that has a port offset of 100:

[disconnected]> connect 127.0.0.1:11322 

[hostname2@cluster//containers/default]>

Press the tab key to display available commands and options. Use the -hoption to display help text.

CLI is used to gracefully shutdown running servers. This ensures that Data Grid passivates all entries to disk and persists state.

• Use the shutdown server command to stop individual servers.

[//containers/default]> shutdown server $hostname 

• Use the shutdown cluster command to stop all servers joined to the cluster.

[//containers/default]> shutdown cluster 

Data Grid Operator

The OpenShift Operators Tech Topic and the Operators in the CoreOS documentation are simplified resources for more details about Operators.

If new to OpenShift you can try  Interactive learning.

Data Grid Operator helps to create, configure, and manage Data Grid clusters. You can try Katakoda.com - Getting Started with Data Grid on OpenShift

Red Hat Data Grid 8.0 introduces a fully supported Operator that provides operational intelligence, using Kubernetes APIs to handle operations and manage application life-cycles. As a result, it’s easier than ever before to deploy and manage complex applications—like distributed datastores that is consumed as a service. They get upgraded automatically, with no need for human intervention.

Prerequisites

• Create a Data Grid Operator subscription.
• Have an oc client

Data Grid Operator adds a new Custom Resource (CR) of type Infinispan that lets you handle Data Grid clusters as complex units on OpenShift.

You configure Data Grid clusters running on OpenShift by modifying the Infinispan CR.

The minimal Infinispan CR for Data Grid clusters is as follows:

apiVersion: infinispan.org/v1

kind: Infinispan

metadata:

  name: ---> names the Data Grid Cluster

spec:

  replicas:2 ---> specifies the number of nodes in Cluster.

Procedure

1. Specify the number of Data Grid nodes in the cluster with spec.replicas in your Infinispan CR.

   For example, create a cr_demo.yaml file as follows:

   YAML

    

   
   

   
   

   
   

   
   

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   1

   
   

   
   

    

   1

   $ cat > cr_demo.yaml<<EOF

   2

   apiVersion: infinispan.org/v1

   3

   kind: Infinispan

   4

   metadata:

   5

     name: example-rhdatagrid

   6

   spec:

   7

     replicas: 2

   8

   EOF

   
   

   
   

2. Apply your Infinispan CR.

$ oc apply -f cr_minimal.yaml

Verify Data Grid Operator creating the Data Grid nodes.

$ oc get po

NAME                        READY  STATUS              RESTARTS   AGE
infinispan-operator-0       1/1    Running             0          3m
example-rhdatagrid-3        1/1    Running             0          8s
example-rhdatagrid-2        1/1    Running             0          8s
example-rhdatagrid-1        1/1    Running             0          8s

Cluster view can be verified from logs :

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$ oc logs example-rhdatagrid-0 | grep ISPN000094

INFO  [org.infinispan.CLUSTER] (MSC service thread 1-2) \

ISPN000094: Received new cluster view for channel infinispan: \

[example-rhdatagrid-0|0] (1) [example-rhdatagrid-0]

INFO  [org.infinispan.CLUSTER] (jgroups-3,{example_crd_name-0) \

ISPN000094: Received new cluster view for channel infinispan: \

[example-rhdatagrid-0|1] (2) [example-rhdatagrid-0, example-rhdatagrid-1]