Hazelcast Service

The Hazelcast service is an implementation of a distributed cache using Hazelcast In-Memory Data Grid. This service doesn't present a user-accessible endpoint, but rather is intended for use in a microservices environment where other services are the clients.

Getting Started

Build the service with:

mvn -Pexec clean package
# Optional: use -Pdocker instead of -Pexec to build a docker image

NOTE: The Hazelcast service uses Spring Cloud service discovery to discover service instances and form a clustered cache. Therefore, either the k8s or consul profile must be enabled to support service discovery. For local testing, it is easiest to use consul. These instructions

1. First, refer to services/README for launching the config service.

2. Ensure that the PKI Dir is checked out locally somewhere, and set in the environment variable PKI_DIR.

3. Launch consul:

   mkdir /tmp/consul.d
   cat > /tmp/consul.d/consul.json <<_EOF_
   {
       "datacenter": "demo_dc",
       "disable_update_check": true,
       "enable_agent_tls_for_checks": true,
       "key_file": "$PWD/datawave-spring-boot-starter/src/main/resources/pki/server-key.pem",
       "cert_file": "$PWD/datawave-spring-boot-starter/src/main/resources/pki/server-crt.pem",
       "ca_file": "$PWD/datawave-spring-boot-starter/src/main/resources/pki/ca.pem"
   }
   _EOF_
   consul agent -dev -ui -config-dir=/tmp/consul.d

   Or, if you have docker, use the following:

   docker run -d --rm --name consul --network=host -v $PWD/datawave-spring-boot-starter/src/main/resources/pki:/pki \
       -e CONSUL_LOCAL_CONFIG='{"datacenter": "demo_dc", \
           "disable_update_check": true, "enable_agent_tls_for_checks": true, \
           "key_file": "/pki/server-key.pem", "cert_file": "/pki/server-crt.pem", \
           "ca_file": "/pki/ca.pem"}' \
       consul:1.0.3

4. Launch this service as follows, with the consul profile to enable consul-based service discovery.

   java -jar service/target/hazelcast-service-*-exec.jar --spring.profiles.active=dev,consul,nomessaging
   

5. Optionally run two more copies to reach a three node Hazelcast cluster:

   java -jar service/target/hazelcast-service-*-exec.jar --spring.profiles.active=dev,consul,nomessaging --cachePort=8843
   java -jar service/target/hazelcast-service-*-exec.jar --spring.profiles.active=dev,consul,nomessaging --cachePort=8943

See sample_configuration/cache-dev.yml and configure as desired

The hazelcast server on its own provides no rest interface. Instead it is intended to be used with a Hazelcast client. The client source code can be found in the client module. It acts as a Spring Boot cache provider and can be used as a normal Spring Boot cache.