Druid implements an extension system that allows for adding functionality at runtime. Extensions are commonly used to add support for deep storage (like HDFS and S3), metadata stores (like MySQL and PostgreSQL), new aggregators, new input formats, and so on.
Production clusters will generally use at least two extensions; one for deep storage and one for a metadata store. Many clusters will also use additional extensions.
Imply bundles many commonly used extensions out of the box, including all
core Druid extensions. See the list of extensions below for your options. You
can load bundled extensions by adding their names to your common.runtime.properties
druid.extensions.loadList property. For example, to load the postgresql-metadata-storage and
druid-hdfs-storage extensions, use the configuration:
You can also install community and third-party extensions not already bundled with the Imply
distribution. To do this, first download the extension and then install it into your
dist/druid/extensions/ directory. You can download extensions from their distributors directly, or
if they are available from Maven, the included pull-deps tool can download them for you. To use pull-deps
specify the full Maven coordinate of the extension in the form
If you are installing a Druid community-contributed extension, use a coordinate like
org.apache.extensions.contrib:druid-orc-extensions:0.15.0-incubating. The version you provide should match the
community Druid version that your Imply distribution is based on. For example, to install
java \ -cp "dist/druid/lib/*" \ -Ddruid.extensions.directory="dist/druid/extensions" \ -Ddruid.extensions.hadoopDependenciesDir="dist/druid/hadoop-dependencies" \ org.apache.druid.cli.Main tools pull-deps \ --no-default-hadoop \ -c "org.apache.druid.extensions.contrib:druid-orc-extensions:0.15.0-incubating"
druid.extensions.loadList in common.runtime.properties to instruct Druid to load the extension.
Community extensions are contributed by Druid community members but are not necessarily maintained on an ongoing basis by Druid committers. The Druid documentation contains a list of community extensions.
Imply does not provide support for community extensions.
The following extensions are bundled with the Imply distribution. To load bundled extensions, see Loading bundled extensions. To install other extensions, see Loading community and third-party extensions.
Core extensions are maintained by Druid committers. Some are in experimental status and some are fully production-tested Druid components.
For additional documentation on these extensions, see the Druid documentation.
|druid-avro-extensions||Support for data in Apache Avro data format.||link|
|druid-caffeine-cache||A local cache implementation backed by Caffeine.||link|
|druid-datasketches||Support for approximate counts and set operations with DataSketches.||link|
|druid-hdfs-storage||HDFS deep storage.||link|
|druid-histogram||Approximate histograms and quantiles aggregator.||link|
|druid-kafka-eight||Kafka ingest firehose (high level consumer).||link|
|druid-kafka-extraction-namespace||Kafka-based namespaced lookup. Requires namespace lookup extension.||link|
|druid-kafka-indexing-service||Supervised, exactly-once Kafka ingestion.||link|
|druid-kerberos||Kerberos authentication for druid nodes.||link|
|druid-lookups-cached-global||A module for lookups providing a jvm-global eager caching for lookups. It provides JDBC and URI implementations for fetching lookup data.||link|
|druid-lookups-cached-single||Per lookup caching module to support the use cases where a lookup needs to be isolated from the global pool of lookups.||link|
|druid-protobuf-extensions||Support for data in Protobuf data format.||link|
|druid-s3-extensions||Interfacing with data in AWS S3, and using S3 as deep storage.||link|
|druid-stats||Statistics related module including variance and standard deviation.||link|
|mysql-metadata-storage||MySQL metadata store.||link|
|postgresql-metadata-storage||PostgreSQL metadata store.||link|
|simple-client-sslcontext||Simple SSLContext provider module to be used by an internal HttpClient talking to other nodes over HTTPS.||link|