Querying Elasticsearch

Swatee Chand has a tutorial on querying Elasticsearch:

In Elasticsearch, aggregations framework is responsible for providing the aggregated data based on a search query. Aggregations can be composed together in order to build complex summaries of the data. For a better understanding, consider it as a unit-of-work. It develops analytic information over a set of documents that are available in Elasticsearch. Various types of aggregations are available, each of them having its own purpose and output. For simplification, they are generalized to 4 major families:

  1. Bucketing

    Here each bucket is associated with a key and a document. Whenever the aggregation is executed, all the buckets criteria are evaluated on every document. Each time a criterion matches, the document is considered to “fall in” the relevant bucket.

  2. Metric

    Metrics are the aggregations which are responsible for keeping a track and computing the metrics over a set of documents.

  3. Matrix

    Matrix are the aggregations which are responsible for operating on multiple fields. They produce a matrix result out of the values extracted from the requested document fields. Matrix does not support scripting.

  4. Pipeline

    Pipeline are the aggregations which are responsible for aggregating the output of other aggregations and their associated metrics together.

If you deal with Elasticsearch (or have log data that you want to query through), this tutorial will give you an idea of what you can do.

Related Posts

Replicating Solr Indexes

Nirmal Prabhu walks us through configuring replicated Solr instances: Step 4: [Creating master Core] First, we need to create a core for indexing the data. The Solr create command has the following options: -c <name> — Name of the core or collection to create (required). -d <confdir> — The configuration directory, useful in the SolrCloud mode. -n <configName> — The configuration […]

Read More

Connecting To Elasticsearch With R

Jerod Johnson has a sample of connecting to Elasticsearch with R: You will need the following information to connect to Elasticsearch as a JDBC data source: Driver Class: Set this to cdata.jdbc.elasticsearch.ElasticsearchDriver. Classpath: Set this to the location of the driver JAR. By default, this is the lib subfolder of the installation folder. The DBI functions, […]

Read More

Categories

November 2017
MTWTFSS
« Oct Dec »
 12345
6789101112
13141516171819
20212223242526
27282930