Lastfm Archive

A tool for creating local Last.fm scrobble file archive and analytics.

The software is currently experimental and in preliminary development. It should eventually provide capability to perform ETL and analytic tasks on Lastfm scrobble data.

Current Usage

Download and create a file archive of Lastfm scrobble tracks via an Elixir application or interactive Elixir by invoking iex -S mix command line action while in software home directory.

  # archive all data of a default user specified in configuration
  LastfmArchive.sync # subsequent calls download only latest scrobbles

  # archive all data of any Lastfm user
  # the data is stored in directory named after the user
  LastfmArchive.sync("a_lastfm_user")

Scrobbles are extracted and stored in the file archive on a daily basis (granularity). The software has a built-in cache to remember and resume from the previous downloads. It skips already downloaded scrobbles and does not make further requests to Last.fm API.

The data is currently in raw Lastfm recenttracks JSON format, chunked into 200-track (max) gzip compressed pages and stored within directories corresponding to the days when tracks were scrobbled. The file archive in a main directory specified in configuration - see below.

Other Usage

To generate a TSV file archive from downloaded data:

  # transform all existing data in a file archive into TSV files
  LastfmArchive.transform_archive("a_lastfm_user")

See transform_archive/2.

To load all transformed TSV data from the archive into Solr:

  # define a Solr endpoint with %Hui.URL{} struct
  headers = [{"Content-type", "application/json"}]
  url = %Hui.URL{url: "http://localhost:8983/solr/lastfm_archive", handler: "update", headers: headers}

  LastfmArchive.load_archive("a_lastfm_user", url)

The function finds TSV files from the archive and send them to Solr for ingestion one at a time. It uses Hui client to interact with Solr and the Hui.URL.t/0 struct for Solr endpoint specification.

Requirement

This tool requires Elixir and Erlang, see installation details for various operating systems.

Installation

lastfm_archive is available in Hex, the package can be installed by adding lastfm_archive to your list of dependencies in mix.exs:

  def deps do
    [
      {:lastfm_archive, "~> 0.9"}
    ]
  end

Documentation can be found at https://hexdocs.pm/lastfm_archive.

Configuration

Add the following entries in your config - config/config.exs. For example, the following specifies a default_user and a main file location for multiple user archives, ./lastfm_data/ relative to the software home directory.

You also need to specify an api-key in the config, so that the application can access Lastfm API.

  config :lastfm_archive,
    api: %{api_key: "api-key", endpoint: "http://ws.audioscrobbler.com/", method: ""},
    user: "default_user", # the default user
    data_dir: "./lastfm_data/", # main directory for multiple archives
    per_page: 200, # 200 is max no. of tracks per call permitted by Lastfm API 
    interval: 1000 # milliseconds between requests cf. Lastfm's max 5 reqs/s rate limit


  # optional: Solr endpoint for Lastfm data loading
  config :hui, :lastfm_archive,
    url: "http://localhost:8983/solr/lastfm_archive",
    handler: "update",
    headers: [{"Content-type", "application/json"}]

See sync/2 for other configurable archiving options, e.g. interval, per_page.

See Hui for more details on Solr configuration.

An api_key must be configured to enable Lastfm API requests, see https://www.last.fm/api ("Get an API account").