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README.md

Cohort demonstration using the Egeria in-memory metadata repository

In-memory metadata repositories can be used with Egeria for demonstrations of Egeria capabilities without needing to install another metadata repository. This is NOT for production.

Figure 1:

Figure 1: Cohort set up for demo

Docker

This demo involves starting 2 OMAG Server Platforms each running logical server instances called myservera and myserverb connected together as part of an open metadata repository cohort called cocoCohort. Apache Kafka is used to publish and consume events, resulting in the metadata being synchronised between the two metadata repositories.

The demo uses Apache Kafka in a Docker container. See Kafka-Docker for details on how to set this up

Egeria setup

Start an OMAG server platform either from the Egeria install or from IntelliJ.

Here is the IntelliJ configuration for an OMAG server platform using port 8080. Note you should change to 9443 which is now the default for Egeria since switching to https by default:

Figure 2:

Figure 2: OMAG Server Platform run configuration for port 9443

In a similar way start a second OMAG server platform on port 9444 using -Dserver.port=9444.

Issue the following REST calls

POST https://localhost:9443/open-metadata/admin-services/users/david/servers/myservera/event-bus

{
  "producer":
  {
    "bootstrap.servers":"localhost:9092",
    "acks":"all",
    "retries":"0",
    "batch.size":"16384",
    "linger.ms":"1",
    "buffer.memory":"33554432",
    "max.request.size":"10485760",
    "key.serializer":"org.apache.kafka.common.serialization.StringSerializer",
    "value.serializer":"org.apache.kafka.common.serialization.StringSerializer",
    "kafka.omrs.topic.id":"cocoCohort"
  },
  "consumer":
  {
    "bootstrap.servers":"localhost:9092",
    "zookeeper.session.timeout.ms":"400",
    "zookeeper.sync.time.ms":"200",
    "fetch.message.max.bytes":"10485760",
    "max.partition.fetch.bytes":"10485760",
    "key.deserializer":"org.apache.kafka.common.serialization.StringDeserializer",
    "value.deserializer":"org.apache.kafka.common.serialization.StringDeserializer",
    "kafka.omrs.topic.id":"cocoCohort"
  }
}
POST https://localhost:9443/open-metadata/admin-services/users/david/servers/myservera/access-services
POST https://localhost:9443/open-metadata/admin-services/users/david/servers/myservera/cohorts/cocoCohort
POST https://localhost:9443/open-metadata/admin-services/users/david/servers/myservera/local-repository/mode/in-memory-repository
POST https://localhost:9443/open-metadata/admin-services/users/david/servers/myservera/instance

Wait for the last REST call to complete. If you have INFO logging switched on, Kafka will log to the console for each publish of a type.

Repeat the above commands for OMAG server platform running serverb.

POST https://localhost:9444/open-metadata/admin-services/users/david/servers/myserverb/...

Using the Subject Area OMAS to test the synchronization

POST https://localhost:9443/servers/myservera/open-metadata/access-services/subject-area/users/david/glossaries

{
  "class":"Taxonomy",
  "name":"Glossary2",
  "description":"test glossary 1 ",
  "usage":"usage A",
  "nodeType":"Taxonomy"
}

The response should be something like:

{
    "class": "GlossaryResponse",
    "relatedHTTPCode": 200,
    "responseCategory": "Glossary",
    "glossary": {
        "nodeType": "Taxonomy",
        "name": "Glossary2",
        "systemAttributes": {
            "status": "ACTIVE",
            "createdBy": "david",
            "createTime": "2018-09-11T11:24:00.543+0000",
            "version": 1,
            "guid": "9b08873e-5317-4199-9c5e-a7213947f271"
        },
        "description": "test glossary 1 ",
        "classifications": [
            {
                "systemAttributes": {
                    "status": "ACTIVE",
                    "version": 0
                },
                "classificationName": "Taxonomy"
            }
        ],
        "governanceActions": {},
        "usage": "usage A"
    }
}

Note the guid and issue a get to other server (9444).

GET https://localhost:9444/servers/myserverb/open-metadata/access-services/subject-area/users/david/glossaries/9b08873e-5317-4199-9c5e-a7213947f271

You should get the glossary back.

Working with Egeria

Be aware that files are created for the config and registry store. They will be:

omag.server.myservera.config
omag.server.myserverb.config
myservera.cocoCohort.registrystore
myserverb.cocoCohort.registrystore

If you want to start a clean system, you should delete these files and restart the servers.

License: CC BY 4.0, Copyright Contributors to the ODPi Egeria project.