[AVRO-1035] Add the possibility to append to existing avro files

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Assignee: Unassigned
• Reporter: Vyacheslav Zholudev
• Created: 22/Feb/12 15:34
• Updated: 07/Feb/13 17:54
• Resolved: 07/Feb/13 00:09

Description

Currently it is not possible to append to avro files that were written and closed.

Here is a Scott Carey's reply on the mailing list:

It is not possible without modifying DataFileWriter. Please open a JIRA
ticket.

It could not simply append to an OutputStream, since it must either:

• Seek to the start to validate the schemas match and find the sync
  marker, or
• Trust that the schemas match and find the sync marker from the last block

DataFileWriter cannot refer to Hadoop classes such as FileSystem, but we
could add something to the mapred module that takes a Path and FileSystem
and returns
something that implemements an interface that DataFileWriter can append
to. This would be something that is both a
http://avro.apache.org/docs/1.6.2/api/java/org/apache/avro/file/SeekableInp
ut.html
and an OutputStream, or has both an InputStream from the start of the
existing file and an OutputStream at the end.