GC writer, used for incremental compaction, cannot be currently used if interposer
consumer is used. That's because compaction assumes that GC writer will be operated
only by a single compaction writer at a given point in time.
With interposer consumer, multiple writers will concurrently operate on the same
GC writer, leading to race condition which potentially result in use-after-free.
Let's disable GC writer if interposer consumer is enabled. We're not losing anything
because GC writer is currently only needed on strategies which don't implement an
interposer consumer. Resharding will always disable GC writer, which is the expected
behavior because it doesn't support incremental compaction yet.
The proper fix, which allows GC writer and interposer consumer to work together,
will require more time to implement and test, and for that reason, I am postponing
it as #6472 is a showstopper for the current release.
Fixes#6472.
tests: mode(dev).
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Reviewed-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <20200526195428.230472-1-raphaelsc@scylladb.com>
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