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Doug Cutting commented on AVRO-1704: ------------------------------------ +1 overall. Two minor questions: - Is the change to the createDatumReader/Writer API fully back-compatible? - I think a few of the new public methods don't have javadoc. It's probably worth building the docs and glancing through them to see how they look. That usually inspires a lot of improvements and is especially useful with new APIs like this. Other than that, LGTM. > 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 > Assignee: Niels Basjes > Fix For: 1.9.0, 1.8.3 > > Attachments: AVRO-1704-2016-05-03-Unfinished.patch, > AVRO-1704-20160410.patch > > > 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)