This new interface allows table to communicate multiple changes in the
SSTable set with a single call, which is useful on compaction completion
for example.
With this new interface, the size tiered backlog tracker will be able to
know when compaction completed, which will allow it to recompute tiers
and their backlog contribution, if any. Without it, tiered tracker
would have to recompute tiers for every change, which would be terribly
expensive.
The old remove/add interface are being removed in favor of the new one.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
If the tracker is disabled, we never get to access the underlying
implementation anymore. It makes sense to clear _impl on
disable(). So table::stop() can call its backlog tracker's disable
method, clearing all its state. This is important for clean
shutdown, as any sstable in tracker state may cause sstable
manager to hang when being stopped.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
Since compaction is layered on top of sstables, let's move all compaction code
into a new top-level directory.
This change will give me extra motivation to remove all layer violations, like
sstable calling compaction-specific code, and compaction entanglement with
other components like table and storage service.
Next steps:
- remove all layer violations
- move compaction code in sstables namespace into a new one for compaction.
- move compaction unit tests into its own file
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20210707194058.87060-1-raphaelsc@scylladb.com>
