qos: disable dynamic replica reduction #7888
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Motivation: Due to concurrent nature of message processing in dCache data migration by `migration move` command we might observe a raise condition between PIN and UNPIN operations, which might be sent and processed in different order. Thus UNPIN, followed by PIN, with expected result in file being pinned may be processed as PIN followed by UNPIN, with file ending in unpinned state. The reduction of pinned replicas on migration event can be skipped. The redundant pin will be adjusted by scanner on the next run. Modification: Skip unpinning if it's not done by scanner. Result: no danger in running into raise condition with a cost of redundant pinned replica for some period of time. Acked-by: Dmitry Litvintsev Target: master, 11.0, 10.2, 10.1, 10.0, 9.2 Require-book: no Require-notes: yes (cherry picked from commit ef27b1f) Signed-off-by: Tigran Mkrtchyan <[email protected]>
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Motivation:
Due to concurrent nature of message processing in dCache data migration by
migration movecommand we might observe a raise condition between PIN and UNPIN operations, which might be sent and processed in different order. Thus UNPIN, followed by PIN, with expected result in file being pinned may be processed as PIN followed by UNPIN, with file ending in unpinned state.The reduction of pinned replicas on migration event can be skipped. The redundant pin will be adjusted by scanner on the next run.
Modification:
Skip unpinning if it's not done by scanner.
Result:
no danger in running into raise condition with a cost of redundant pinned replica for some period of time.
Acked-by: Dmitry Litvintsev
Target: master, 11.0, 10.2, 10.1, 10.0, 9.2
Require-book: no
Require-notes: yes
(cherry picked from commit ef27b1f)