Atlas search investigation¶
There are several approaches to integrate searching within Apache Atlas, we describe multiple options below:
- Use REST API’s
Directly using the Atlas API’s is quick to implement and easy to setup for administrators. Atlas uses a search engine underwater (embedded Solr) to perform search queries, thus in theory this method should scale up. Disadvantages are that we are limited to the REST api that Atlas offers, we could potentially add functionality via pull requests and extend the search capabilities. The advanced search provides a DSL which contains basic forms of aggregation and arithmetic.
- Use Data Builder to fill Elasticsearch from Atlas
Adopting Atlas within the Data Builder to fill Elasticsearch is a relatively straightforward way of staying compatible with the Neo4j database. It could either be pulling data from Atlas or being pushed by Kafka. This method requires a setup of Elasticsearch and Airflow, which increases the amount of infrastructure and maintenance. Another disadvantage is that with a big inflow of metadata this method might not scale as well as the other methods.
- Use underlying Solr or Elasticsearch from Apache Atlas
Within Atlas there is the possibility to open up either Solr or the experimental Elasticsearch. It depends on janusgraph (the behind the scenes graph database) which populates the search engine. Therefore the search engine would not be compatible with the data builder setup. Adoption of such a search engine would require either new queries, some kind of transformer within the search engine, or changes within Atlas itself.
Both the REST API approach and the data builder approach can be implemented and be configurable. Both approaches have their own benefits, the data builder together provides a more fine-tuned search whereas the Atlas REST API comes out of the box with Atlas. The last approach of using the underlying search engine from Atlas provides direct access to all the meta data with a decent search API. However, integration would be less straight forward as the indexes would differ from the data builders search engine loader.
The focus is initially to implement the REST API approach and afterwards potentially implement an Atlas data extractor and importer within the Amundsen Data Builder. So that administrators have more flexibility in combining data sources.