Installation and Configuration

Installation and Configuration

Before you can work with Couchbase and Elasticsearch, you need to set up the Couchbase Elasticsearch plug-in, a Couchbase cluster, and an Elasticsearch cluster. After you install the clusters, start them. The Couchbase cluster stores any items from your application and sends replicas of these items to the Elasticsearch cluster for indexing. Your Couchbase cluster can contain one or more instances of Couchbase server, and your Elasticsearch cluster can contain one or more instances of Elasticsearch.

For compatibility information, see Release Notes.

For now, you probably need only one instance of Couchbase Server running in a cluster and one instance of the Elasticsearch engine. Later, as you test your integration under load and deploy your implementation, you will need to add more servers to handle the workload. At this phase, the most important point about the Couchbase Server installation is to make sure that you include the beer-sample sample data bucket, which is available as an installation option. The examples in this guide build on data contained in the sample database.

Installing the Couchbase Elasticsearch Plug-in

To enable full-text search of data in Couchbase, you transmit data from a Couchbase cluster to an Elasticsearch cluster where it will be indexed by Elasticsearch. The Couchbase Plug-in for Elasticsearch helps transmit data from Couchbase using a protocol understood by Elasticsearch. The plug-in ensures that information from Couchbase can be mapped and converted into data which Elasticsearch will index and query.

To install the Couchbase Elasticsearch plug-in:

  1. Go to your installation directory for Elasticsearch:
    cd elasticsearch-<version>
  2. Install the Couchbase Plug-in. Replace the version number with the appropriate one.

    To install the Elasticsearch 1.x compatible plugin, run the following command from your Elasticsearch installation folder:

    bin/plugin --install transport-couchbase --url \
    http://packages.couchbase.com.s3.amazonaws.com/releases/\
    elastic-search-adapter/2.1.2/elasticsearch-transport-couchbase-2.1.2.zip 
    To install the ES 2.1.1 compatible version, run the following command from your Elasticsearch installation folder:
    bin/plugin --install --url \
    https://github.com/couchbaselabs/elasticsearch-transport-couchbase/\
    releases/download/v2.2.1.2/elasticsearch-transport-couchbase-2.2.1.2.zip

    After a successful installation, the plug-in installer returns:

    DONE Installed transport-couchbase
  3. Set the user name and password for the plug-in:
    echo "couchbase.password: password" >> config/elasticsearch.yml; 
    echo "couchbase.username: Administrator" >> config/elasticsearch.yml
  4. Install head, a third-party plug-in for Elasticsearch that provides a simple web-based interface you can use to interact with Elasticsearch:
     bin/plugin --install mobz/elasticsearch-head 
  5. Start Elasticsearch:
     bin/elasticsearch 

    Elasticsearch starts and runs on your machine in the background.

  6. In a browser, go to http://localhost:9200/_plugin/head/ to open the administrative client for Elasticsearch.

    The following screen with a randomized name appears:

At this point you have the Couchbase Elasticsearch plug-in and the Elasticsearch engine installed and running. You can now set up the index templates for Elasticsearch and set up Couchbase Server to send data to Elasticsearch.

Updating Configurations

After installation you are now ready to transfer data from Couchbase Server to Elasticsearch and begin indexing the data. In Elasticsearch you will create an index template to define the scope of indexing and searching. In Couchbase Server, you will change the default setting for replication so that the timing and performance will work with Elasticsearch clusters.

  1. Configure an index template for Elasticsearch to use on the information sent from Couchbase.
    shell> curl -XPUT http://localhost:9200/_template/couchbase \
    -d @plugins/transport-couchbase/couchbase_template.json 

    The template specified in the command is included with the Couchbase Elasticsearch plug-in. You can also provide your own index template. If you provide more than one template, you can maintain multiple indexes that can be individually updated.

    Upon success, Elasticsearch returns:

    {"ok":true,"acknowledged":true}
  2. For each Couchbase data bucket that you want to search, create an empty index in Elasticsearch:
    shell> curl -XPUT http://localhost:9200/beer-sample

    The command names the index beer-sample.

    Upon success Elasticsearch returns:

    {"ok":true,"acknowledged":true}
  3. Set the number of concurrent requests Elasticsearch can process:
    shell> echo "couchbase.maxConcurrentRequests: 1024" >> config/elasticsearch.yml 
  4. Stop and restart Elasticsearch for your changes to take effect.
  5. Set the number of concurrent replicators in Couchbase Server to 8:
    shell> curl -X POST -u Administrator:password1 http://10.4.2.4:8091/ \
    internalSettings -d xdcrMaxConcurrentReps=8  

    When Couchbase Server successfully updates this setting, it sends a response similar to this:

    HTTP/1.1 200 OK 
    Server: Couchbase Server 3.0.0-1209-rel
    Pragma: no-cache Date: Wed, 28 Nov 2012 18:20:22 GMT 
    Content-Type: application/json Content-Length: 188
    Cache-Control: no-cache 

    One of the issues that can occur when an Elasticsearch node is overwhelmed by replication from Couchbase is that the node can fail. If this does occur, you may also experience errors from remaining nodes.