Fixes#5899
When terminating (closing) a segment, we write a trailing block
of zero so reader can have an empty region after last used chunk
as end marker. This is due to using recycled, pre-allocated
segments with potentially non-zero data extending over the point
where we are ending the segment (i.e. we are not fully filling
the segment due to a huge mutation or similar).
However, if we reach end of segment writing the final block
(typically many small mutations), the file will end naturally
after the data written, and any trailing zero block would in fact
just extend the file further. While this will only happen once per
segment recycled (independent on how many times it is recycled),
it is still both slightly breaking the disk usage contract and
also potentially causing some disk stalls due to metadata changes
(though of course very infrequent).
We should only write trailing zero if we are below the max_size
file size when terminating
Adds a small size check to commitlog test to verify size bounds.
(Which breaks without the patch)
v2:
- Fix test to take into account that files might be deleted
behind our backs.
v3:
- Fix test better, by doing verification _before_ segments are
queued for delete.
Message-Id: <20200226121601.15347-2-calle@scylladb.com>
Message-Id: <20200324100235.23982-1-calle@scylladb.com>
This reverts commit 0b34d88957. According
to Rafael Avila de Espindola:
"I have bisected the recent failures [in commitlog_test] on next to this
patch."
Fixes#5899
When terminating (closing) a segment, we write a trailing block
of zero so reader can have an empty region after last used chunk
as end marker. This is due to using recycled, pre-allocated
segments with potentially non-zero data extending over the point
where we are ending the segment (i.e. we are not fully filling
the segment due to a huge mutation or similar).
However, if we reach end of segment writing the final block
(typically many small mutations), the file will end naturally
after the data written, and any trailing zero block would in fact
just extend the file further. While this will only happen once per
segment recycled (independent on how many times it is recycled),
it is still both slightly breaking the disk usage contract and
also potentially causing some disk stalls due to metadata changes
(though of course very infrequent).
We should only write trailing zero if we are below the max_size
file size when terminating
Adds a small size check to commitlog test to verify size bounds.
(Which breaks without the patch)
Message-Id: <20200226121601.15347-2-calle@scylladb.com>
1. Move tests to test (using singular seems to be a convention
in the rest of the code base)
2. Move boost tests to test/boost, other
(non-boost) unit tests to test/unit, tests which are
expected to be run manually to test/manual.
Update configure.py and test.py with new paths to tests.
