GitHub user jkff opened a pull request:
https://github.com/apache/beam/pull/3590
[BEAM-2628] Makes AvroSource not open files while splitting
https://issues.apache.org/jira/browse/BEAM-2628
AvroSource would open each file while splitting, in
createForSubrangeOfFile, in order to fetch the file's codec, sync marker and
writer schema. This is extremely slow with a large number of files, and
unnecessary - none of this information is needed for splitting, only for
reading. This PR moves that code into the reader: now, when we open an
AvroReader, we first read the file metadata.
This effectively moves the overhead of opening every file from
{sequentially during splitting} to {in parallel inside every work item}, which
is much better and gets rid of the sequential bottleneck in splitting.
There's a few more minor simplifications (e.g. removing unnecessary lazy
initialization and such) and immaterial renames to AvroSource in this PR.
AvroSource is not a public API surface class (is marked Experimental), so this
is fine.
R: @reuvenlax
CC: @matthewlang
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/jkff/incubator-beam avro-split-2
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/beam/pull/3590.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #3590
----
commit 4973caaa57b9959944d503de1f33bd7d7c64b027
Author: Eugene Kirpichov <kirpic...@google.com>
Date: 2017-07-18T20:40:52Z
Minor changes to AvroSource in preparation for refactoring
commit 2bfb3d50503627308d431909bac0fe768ee8d688
Author: Eugene Kirpichov <kirpic...@google.com>
Date: 2017-07-18T21:09:03Z
Gets rid of opening Avro files in createForSubrangeOfFile codepath
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