avro-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Daniel Schierbeck (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (AVRO-1704) Standardized format for encoding messages with Avro
Date Mon, 21 Sep 2015 08:10:04 GMT

    [ https://issues.apache.org/jira/browse/AVRO-1704?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14900357#comment-14900357
] 

Daniel Schierbeck commented on AVRO-1704:
-----------------------------------------

[~rdblue] If there's already widespread usage of `<sha256><data>` then I can simply
implement that.

> Standardized format for encoding messages with Avro
> ---------------------------------------------------
>
>                 Key: AVRO-1704
>                 URL: https://issues.apache.org/jira/browse/AVRO-1704
>             Project: Avro
>          Issue Type: Improvement
>            Reporter: Daniel Schierbeck
>
> I'm currently using the Datafile format for encoding messages that are written to Kafka
and Cassandra. This seems rather wasteful:
> 1. I only encode a single record at a time, so there's no need for sync markers and other
metadata related to multi-record files.
> 2. The entire schema is inlined every time.
> However, the Datafile format is the only one that has been standardized, meaning that
I can read and write data with minimal effort across the various languages in use in my organization.
If there was a standardized format for encoding single values that was optimized for out-of-band
schema transfer, I would much rather use that.
> I think the necessary pieces of the format would be:
> 1. A format version number.
> 2. A schema fingerprint type identifier, i.e. Rabin, MD5, SHA256, etc.
> 3. The actual schema fingerprint (according to the type.)
> 4. Optional metadata map.
> 5. The encoded datum.
> The language libraries would implement a MessageWriter that would encode datums in this
format, as well as a MessageReader that, given a SchemaStore, would be able to decode datums.
The reader would decode the fingerprint and ask its SchemaStore to return the corresponding
writer's schema.
> The idea is that SchemaStore would be an abstract interface that allowed library users
to inject custom backends. A simple, file system based one could be provided out of the box.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message