Datahike S3 Backend

The goal of this backend is to support S3. S3 is comparatively cheap, read scalable and requires no dedicated running process for reading, but has higher latency than using a local file system or JDBC server as backend. It is therefore optimal to store large databases that are updated in bulk or mostly appended to. In this case the Datahike cache will reduce the latency on database access. Transactions will still have high latency.

Configuration

Please read the Datahike configuration docs on how to configure your backend. Details about the backend configuration can be found in konserve-s3.A sample configuration is create-database, connect and delete-database:

{:store {:backend :s3
         :bucket "datahike-s3"
         :store-id "instance1"
         :region "us-west-1"
         :access-key "YOUR_ACCESS_KEY"
         :secret "YOUR_ACCESS_KEY_SECRET"}}

This same configuration can be achieved by setting one environment variable for the s3 backend and one environment variable for the configuration of the s3 backend:

DATAHIKE_STORE_BACKEND=s3
DATAHIKE_STORE_CONFIG='{:bucket "datahike-s3-instance" ...}'

Usage

Add to your Leiningen or Boot dependencies:

Now require the Datahike API and the datahike-s3 namespace in your editor or REPL using the keyword :s3. If you want to use other backends than S3 please refer to the official Datahike docs.

Run Datahike in your REPL

  (ns project.core
    (:require [datahike.api :as d]
              [datahike-s3.core]))

  (def cfg {:store {:backend :s3
                    :bucket "datahike-s3"
                    :store-id "instance1"
                    :region "us-west-1"
                    :access-key "YOUR_ACCESS_KEY"
                    :secret "YOUR_ACCESS_KEY_SECRET"}})

  ;; Create a database at this place, by default configuration we have a strict
  ;; schema validation and keep historical data
  (d/create-database cfg)

  (def conn (d/connect cfg))

  ;; The first transaction will be the schema we are using:
  (d/transact conn [{:db/ident :name
                     :db/valueType :db.type/string
                     :db/cardinality :db.cardinality/one }
                    {:db/ident :age
                     :db/valueType :db.type/long
                     :db/cardinality :db.cardinality/one }])

  ;; Let's add some data and wait for the transaction
  (d/transact conn [{:name  "Alice", :age   20 }
                    {:name  "Bob", :age   30 }
                    {:name  "Charlie", :age   40 }
                    {:age 15 }])

  ;; Search the data
  (d/q '[:find ?e ?n ?a
         :where
         [?e :name ?n]
         [?e :age ?a]]
    @conn)
  ;; => #{[3 "Alice" 20] [4 "Bob" 30] [5 "Charlie" 40]}

  ;; Clean up the database if it is not needed any more
  (d/delete-database cfg)

Run Tests

  bash -x ./bin/run-integration-tests

License

Copyright © 2023 lambdaforge UG (haftungsbeschränkt)

This program and the accompanying materials are made available under the terms of the Eclipse Public License 1.0.