Setup

You'll need to build from source. For that we will use gradle (https://gradle.org/).

Prerequisite

Make sure that your JAVA_HOME environment variable is set by running:

$ echo $JAVA_HOME

If not, add the following in your .bash_profile or .zshrcr (see this: https://stackoverflow.com/a/6588410)

export JAVA_HOME="$(/usr/libexec/java_home -v 11)"

...and reload it

source ~/.bash_profile
# or
source ~/.zshrc

Build from source

$ cd /path/to/dev/elasticsearch  # your local checkout of the ES repo
$ git checkout master
$ git pull upstream master
$ ./gradlew assemble --parallel

Unzip the build

$ cd distribution/archives/zip/build/distributions
$ unzip elasticsearch-7.0.0-alpha1-SNAPSHOT.zip
$ cd elasticsearch-7.0.0-alpha1-SNAPSHOT

Launch both instances

Launch each instance in a separate terminal window

bin/elasticsearch -E cluster.name=prod1 
# and
bin/elasticsearch -E cluster.name=prod2 -E node.max_local_storage_nodes=2 -E transport.tcp.port=9400

Check that both clusters are up as distinct clusters

$ curl 'http://localhost:9200/'
$ curl 'http://localhost:9201/'

In the example below we will consider :9200 as the leader and :9201 as the follower cluster.

Create Remote cluster

Activate trial on both instances

curl  -X POST http://localhost:9200/_xpack/license/start_trial?acknowlegment=true -H “Content-Type: application/json”
curl  -X POST http://localhost:9201/_xpack/license/start_trial?acknowlegment=true -H “Content-Type: application/json”

Check that the CCR stats API exists

GET _ccr/stats

Create remote cluster (send the request on the remote instance)

PUT _cluster/settings
{
  "persistent": {
    "cluster": {
      "remote": {
        "prod1": {
          "seeds": [
            "127.0.0.1:9300"
          ]
        },
        "prod2": {
          "seeds": [
            "127.0.0.1:9400"
          ]
        }
      }
    }
  }
}

Check the connection

GET _remote/info

You should see that 1 node is connected to each cluster.

Great! Let's now verify that the Cross Cluster Replication works.

Test Cross Cluster Replication

Initiate leader and follower indices

Create the leader index

Important: soft_deletes has to be enabled on the index.
Execute the request on the leader instance

PUT my_index
{
  "settings": {
    "number_of_shards": 1,
    "soft_deletes.enabled": true
  }
}

GET _cat/indices?v

Create the follower index and make it follow the leader

Execute this on the follower cluster (e.g. http://localhost.9201)

PUT my_index_f/_ccr/follow
{
  "remote_cluster" : "prod1",
  "leader_index" : "my_index"
}

GET _cat/indices?v

GET my_index_f/_search

Test replication

Add a document to the leader index and verify that it shows up in the follower index

# localhost:9200
PUT my_index/_doc/1
{
  "foo": "bar"
}

# localhost:9201
GET my_index_f/_search

Add another document

# localhost:9200
PUT my_index/_doc/2
{
  "foo": "qux"
}

# localhost:9201
GET my_index_f/_search

Delete a document

# localhost:9200
DELETE my_index/_doc/1

# localhost:9201
GET my_index_f/_search

sebelga/es-local-remote-cluster.md