DAOS-19381 placement: tolerate DOWNOUT spare in remap chain - #18737
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wangshilong wants to merge 1 commit into
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DAOS-19381 placement: tolerate DOWNOUT spare in remap chain#18737wangshilong wants to merge 1 commit into
wangshilong wants to merge 1 commit into
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A rebuild resumed by rebuild start can run an older rebuild version against a newer pool map. In that history a failed DOWN/DRAIN shard can select a spare candidate which has already transitioned to DOWNOUT. That state is valid for placement remap chaining: the selected spare is not a usable final target, but the existing code already updates the failed shard state and re-adds it to the remap list so placement can look for the next candidate. The assertion that rejects a DOWN/DRAIN failed shard remapping through a DOWNOUT spare is therefore too strict and can abort rebuild scans during interactive rebuild stop/start recovery. Replace the assertion with placement debug logging and keep the existing chained-remap behavior. Add a jump-map placement unit test that drives a DOWN shard through a spare candidate that becomes DOWNOUT and verifies placement continues to a different rebuild target. Signed-off-by: Wang Shilong <shilong.wang@hpe.com>
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Ticket title is 'Aurora engine crash - determine_valid_spares() Assertion' |
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A rebuild resumed by rebuild start can run an older rebuild version against a newer pool map. In that history a failed DOWN/DRAIN shard can select a spare candidate which has already transitioned to DOWNOUT.
That state is valid for placement remap chaining: the selected spare is not a usable final target, but the existing code already updates the failed shard state and re-adds it to the remap list so placement can look for the next candidate. The assertion that rejects a DOWN/DRAIN failed shard remapping through a DOWNOUT spare is therefore too strict and can abort rebuild scans during interactive rebuild stop/start recovery.
Replace the assertion with placement debug logging and keep the existing chained-remap behavior. Add a jump-map placement unit test that drives a DOWN shard through a spare candidate that becomes DOWNOUT and verifies placement continues to a different rebuild target.
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