* rename write.insert.drop.duplicates to write.precombine and set it as true for COW table
* set index.global.enabled default as true
* set compaction.target_io default as 500GB
* [HUDI-2285] Adding Synchronous updates to metadata before completion of commits in data timelime.
- This patch adds synchronous updates to metadata table. In other words, every write is first committed to metadata table followed by data table. While reading metadata table, we ignore any delta commits that are present only in metadata table and not in data table timeline.
- Compaction of metadata table is fenced by the condition that we trigger compaction only when there are no inflight requests in datatable. This ensures that all base files in metadata table is always in sync with data table(w/o any holes) and only there could be some extra invalid commits among delta log files in metadata table.
- Due to this, archival of data table also fences itself up until compacted instant in metadata table.
All writes to metadata table happens within the datatable lock. So, metadata table works in one writer mode only. This might be tough to loosen since all writers write to same FILES partition and so, will result in a conflict anyways.
- As part of this, have added acquiring locks in data table for those operations which were not before while committing (rollback, clean, compaction, cluster). To note, we were not doing any conflict resolution. All we are doing here is to commit by taking a lock. So that all writes to metadata table is always a single writer.
- Also added building block to add buckets for partitions, which will be leveraged by other indexes like record level index, etc. For now, FILES partition has only one bucket. In general, any number of buckets per partition is allowed and each partition has a fixed fileId prefix with incremental suffix for each bucket within each partition.
Have fixed [HUDI-2476]. This fix is about retrying a failed compaction if it succeeded in metadata for first time, but failed w/ data table.
- Enabling metadata table by default.
- Adding more tests for metadata table
Co-authored-by: Prashant Wason <pwason@uber.com>
* Fixes based on tests and some improvements
* Fix the issues after running stress tests
* Fixing checkstyle issues and updating README
Co-authored-by: Rajesh Mahindra <rmahindra@Rajeshs-MacBook-Pro.local>
Co-authored-by: Vinoth Chandar <vinoth@apache.org>
Based on the discussion on stackoverflow:
https://stackoverflow.com/questions/1771679/difference-between-threads-context-class-loader-and-normal-classloader
The Thread.currentThread().getContextClassLoader() should never be used
because the context classloader is not immutable, user can overwrite it
when thread switches, it is also nullable.
The objection here: https://stackoverflow.com/a/36228195 says the
Thread.currentThread().getContextClassLoader() is a JDK design error
and the context classloader is never suggested to be used. The API that
needs classloader should ask the user to set up the right classloader.
