This will allow upcoming work to gently produce a sstable set for
each compaction group view. Example: repaired and unrepaired.
Locking strategy for compaction's sstable selection:
Since sstable retrieval path became futurized, tasks in compaction
manager will now hold the write lock (compaction_state::lock)
when retrieving the sstable list, feeding them into compaction
strategy, and finally registering selected sstables as compacting.
The last step prevents another concurrent task from picking the
same sstable. Previously, all those steps were atomic, but
we have seen stall in that area in large installations, so
futurization of that area would come sooner or later.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Since table_state is a view to a compaction group, it makes sense
to rename it as so.
With upcoming incremental repair, each replica::compaction_group
will be actually two compaction groups, so there will be two
views for each replica::compaction_group.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
That's needed for upcoming changes that will allow ICS to efficiently
retrieve sstable runs.
Next patch will remove candidates from compaction_strategy's interface
to retrieve candidates using this one instead.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
So it can be used in the next patch that will refactor
compaction_state out of class compaction_manager.
Signed-off-by: Benny Halevy <bhalevy@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
This interface is akin to table_state, but compaction manager's
representative instead.
It will allow compaction manager to set goals and contraints on
compaction strategies. It will start by allowing strategy to know
if there's ongoing compaction, which is useful for virtually all
strategies. For example, LCS may want to compact L0 in parallel
with higher levels, to avoid L0 falling behind.
This interface can be easily extended to allow manager to switch
to a reclaim mode, if running out of space, etc.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
