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1545ae2d3b
Today, SSTable cleanup skips to the next partition, one at a time, when it finds that the current partition is no longer owned by this node. That's very inefficient because when a cluster is growing in size, existing nodes lose multiple sequential tokens in its owned ranges. Another inefficiency comes from fetching index pages spanning all unowned tokens, which was described in https://github.com/scylladb/scylladb/issues/14317. To solve both problems, cleanup will now use multi range reader, to guarantee that it will only process the owned data and as a result skip unowned data. This results in cleanup scanning an owned range and then fast forwarding to the next one, until it's done with them all. This reduces significantly the amount of data in the index caching, as index will only be invoked at each range boundary instead. Without further ado, before: `INFO 2023-07-01 07:10:26,281 [shard 0] compaction - [Cleanup keyspace2.standard1 701af580-17f7-11ee-8b85-a479a1a77573] Cleaned 1 sstables to [./tmp/1/keyspace2/standard1-b490ee20179f11ee9134afb16b3e10fd/me-3g7a_0s8o_06uww24drzrroaodpv-big-Data.db:level=0]. 2GB to 1GB (~50% of original) in 26248ms = 81MB/s. ~9443072 total partitions merged to 4750028.` after: `INFO 2023-07-01 07:07:52,354 [shard 0] compaction - [Cleanup keyspace2.standard1 199dff90-17f7-11ee-b592-b4f5d81717b9] Cleaned 1 sstables to [./tmp/1/keyspace2/standard1-b490ee20179f11ee9134afb16b3e10fd/me-3g7a_0s4m_5hehd2rejj8w15d2nt-big-Data.db:level=0]. 2GB to 1GB (~50% of original) in 17424ms = 123MB/s. ~9443072 total partitions merged to 4750028.` Fixes #12998. Fixes #14317. Closes #14469 * github.com:scylladb/scylladb: test: Extend cleanup correctness test to cover more cases compaction: Make SSTable cleanup more efficient by fast forwarding to next owned range sstables: Close SSTable reader if index exhaustion is detected in fast forward call sstables: Simplify sstable reader initialization compaction: Extend make_sstable_reader() interface to work with mutation_source test: Extend sstable partition skipping test to cover fast forward using token