Using a Redis Cluster

By default, JasperReports IO At-Scale uses the redis module to deploy a single redis pod. Redis is a queue where JRIO stores report requests and report output. In applications with high demand, the Redis queue can become a bottleneck for requests. Therefore, an option for high performance needs is to deploy Redis as a separate cluster and configure JRIO to use it instead of its own redis pod.

To implement a Redis cluster, first you need to deploy and configure the cluster itself. Then you need to configure the JasperReports IO At-Scale modules before building the Docker images. Finally, you need to configure the JRIO Helm Chart before deploying the JRIO cluster.

Deploying a Redis Cluster

The Redis cluster is separate from the JasperReports IO At-Scale product: you must obtain and install Redis from a third-party source. Jaspersoft has tested JasperReports IO At-Scale with the Redis cluster and Helm chart available from Bitnami, specifically the Redis 6.0.7-debian-10-r0 image, and the examples in this section are based on their product:

https://github.com/bitnami/charts/tree/master/bitnami/redis-cluster
https://bitnami.com/stack/redis-cluster/helm

After downloading the Redis cluster, download the values-production.yaml file from the Bitnami github repo:

https://github.com/bitnami/charts/blob/master/bitnami/redis-cluster/values-production.yaml

Edit the values-production.yaml file as follows:

Deploy the Bitnami Redis cluster with the additional values-production.yaml file using the following command:

helm install redis bitnami/redis-cluster --values values-production.yaml

The cluster name is right after the word install in the helm command. In this example, the cluster name is redis. The cluster name is used in the redis service name in the JRIO modules configuration, in the format <cluster-name>-redis-cluster. Therefore, the service name for this cluster is redis-redis-cluster.

If you need to delete the Redis cluster, use the following command where redis is the <cluster-name>:

helm delete redis

However, Helm doesn't delete redis volumes, so before you create a new Redis cluster, check the persistent volume claims (pvc) and delete them individually as shown in the following example. There is one volume for each node, so 6 in our example:

redis_ha> kubectl get pvc | grep redis
redis-data-redis-redis-cluster-0 Bound pvc-e715109e-e0df-4a80-a38b-3449a2bd142a 8Gi RWO gp2 2d17h
redis-data-redis-redis-cluster-1 Bound pvc-0f9a9fda-b3d0-46c0-b2c1-13f202637212 8Gi RWO gp2 2d17h
redis-data-redis-redis-cluster-2 Bound pvc-53121613-929e-467e-b607-b0bec6ee75e4 8Gi RWO gp2 2d17h
redis-data-redis-redis-cluster-3 Bound pvc-963d458d-fffa-4bca-bc5c-f4cb21f39373 8Gi RWO gp2 2d17h
redis-data-redis-redis-cluster-4 Bound pvc-84bc2600-48c7-4eb5-93ef-08b02c01a74b 8Gi RWO gp2 2d17h
redis-data-redis-redis-cluster-5 Bound pvc-17db9ab9-44af-4d69-b422-ba9c0da507a1 8Gi RWO gp2 2d17h

redis_ha> kubectl delete pvc redis-data-redis-redis-cluster-0 redis-data-redis-redis-cluster-1
 redis-data-redis-redis-cluster-2 redis-data-redis-redis-cluster-3
 redis-data-redis-redis-cluster-4 redis-data-redis-redis-cluster-5
persistentvolumeclaim "redis-data-redis-redis-cluster-0" deleted
persistentvolumeclaim "redis-data-redis-redis-cluster-1" deleted
persistentvolumeclaim "redis-data-redis-redis-cluster-2" deleted
persistentvolumeclaim "redis-data-redis-redis-cluster-3" deleted
persistentvolumeclaim "redis-data-redis-redis-cluster-4" deleted
persistentvolumeclaim "redis-data-redis-redis-cluster-5" deleted

Configuring JRIO Modules for a Redis Cluster

Before building the Docker images, you have to configure the JasperReports IO At-Scale modules to use your Redis cluster instead of the built-in Redis module. Edit the following files:

jrio-export-docker/jrio/redis-config.yaml
jrio-manager-docker/jrio/redis-config.yaml
jrio-reporting-docker/jrio/redis-config.yaml
jrio-rest-docker/jrio/WEB-INF/redis-config.yaml

Change the configuration as follows, using the Redis service name and password set in the previous examples:

clusterServersConfig:
 password: "mypassword"
 nodeAddresses:
 - "redis://redis-redis-cluster:6379"
codec: !<org.redisson.codec.SerializationCodec> {}

The Redis service name format is <cluster-name>-redis-cluster.

Now you can build the JRIO Docker images and put them into the Docker registry, as described in Building Docker Images.

Configuring JRIO Helm Chart for a Redis Cluster

Before deploying your JasperReports IO At-Scale cluster, you must configure its Helm chart to use the Redis cluster. Make sure the jrio-at-scale-3.0.0/k8s/helm/values.yaml file uses the new images built after updating with the Redis cluster service.

Delete the following files that are no longer needed:

jrio-at-scale-3.0.0/k8s/helm/templates/redis-deployment.yaml
jrio-at-scale-3.0.0/k8s/helm/templates/redis-service.yaml

Then edit the following files:

jrio-at-scale-3.0.0/k8s/helm/templates/jrio-manager-deployment.yaml
jrio-at-scale-3.0.0/k8s/helm/templates/jrio-reporting-deployment.yaml
jrio-at-scale-3.0.0/k8s/helm/templates/jrio-export-deployment.yaml
jrio-at-scale-3.0.0/k8s/helm/templates/jrio-rest-deployment.yaml

In each of them, replace the Redis connection and initialization script with the following:

initContainers:
 - name: redis-connection
   image: alpine:3.11.6
   command: ['sh', '-c', "until nc -vz redis-redis-cluster 6379; do echo waiting for redis; sleep 2; done; echo connected to redis"]

Now you can proceed with Configuring the Helm Chart and Deploying a Cluster in AWS EKS.