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Getting Started

This Elixir library supports convenient encoding and decoding of Avro messages.

It can read the Avro schema from local files or the Confluent® Schema Registry, caching data in memory for performance.

It supports reading and writing data Kafka wire format prefix and from Object Container Files formats. Along with Confluent® Schema References it has Inter-Schema references feature for older Schema Registry versions.

Many thanks to the AvroTurf Ruby gem for the initial inspiration 💙

Add Avrora to your project

Add Avrora to mix.exs as a dependency:

def deps do
  [
    {:avrora, "~> 0.16"}
  ]
end

Configuration

Configure the library in config/config.exs:

config :avrora,
  registry_url: "http://localhost:8081",
  registry_auth: {:basic, ["username", "password"]}, # optional
  schemas_path: Path.expand("./priv/schemas"),
  registry_schemas_autoreg: false, # optional: if you want manually register schemas
  convert_null_values: false, # optional: if you want to keep decoded `:null` values as is
  convert_map_to_proplist: false # optional: if you want to restore the old behavior for decoding map-type
  names_cache_ttl: :timer.minutes(5) # optional: if you want periodic disk reads

• registry_url - URL for the Schema Registry, default nil
• registry_auth – Credentials to authenticate in the Schema Registry, default nil
• schemas_path - Base path for locally stored schema files, default ./priv/schemas
• registry_schemas_autoreg^v0.13 - Flag for automatic schemas registration in the Schema Registry, default true
• convert_null_values^v0.14 - Flag for automatic conversion of decoded :null values into nil, default true
• convert_map_to_proplist^v0.15 restore old behaviour and confiugre decoding map-type to proplist, default false
• names_cache_ttl^v0.10 - Time in ms to cache schemas by name in memory, default :infinity

Set names_cache_ttl to :infinity will cache forever (no more disk reads will happen). This is safe when schemas are resolved in the Schema Registry by numeric id or versioned name, as it is unique. If you need to reload schema from the disk periodically, TTL different from :infinity ensures that.

If the schema is resolved by name it will be always overwritten with the latest schema received from Schema Registry.^v0.10

💡 Disable schemas auto-registration if you want to avoid storing schemas and manually control registration process. Also it is recommended to turn off auto-registration when schemas containing Confluent Schema References.^v0.14

Start cache process

Avrora uses an in-memory cache to speed up schema lookup.

Add it to your supervision tree:

children = [
  Avrora
]

Supervisor.start_link(children, strategy: :one_for_one)

Or start the cache process manually:

{:ok, pid} = Avrora.start_link()

Sponsorship

If you like the project and want to support me on my sleepless nights, you can