Details
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Bug
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Resolution: Fixed
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Critical
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6.5.0
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Triaged
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Yes
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KV-Engine Mad-Hatter GA
Description
While investigating MB-36765, I observed the NonIO and AuxIO threads are incorrect set to the lowest priority - this should only be the case for Writer threads:
$ ps -o pid,tid,ni,pri,comm -p $(pgrep memcached|head -n1) -T|grep "reader\|writer\|aux\|non"
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14714 18837 0 19 mc:reader_0
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...
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14714 18854 0 19 mc:reader_15
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14714 18855 0 19 mc:writer_0
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14714 18856 19 0 mc:writer_1
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14714 18857 19 0 mc:writer_2
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14714 18858 19 0 mc:writer_3
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14714 18859 19 0 mc:auxIO_0
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14714 18860 19 0 mc:auxIO_1
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14714 18861 19 0 mc:auxIO_2
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14714 18862 19 0 mc:nonIO_0
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14714 18863 19 0 mc:nonIO_1
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14714 18864 19 0 mc:nonIO_2
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14714 18865 19 0 mc:nonIO_3
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14714 18866 19 0 mc:nonIO_4
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14714 18867 19 0 mc:nonIO_5
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14714 18868 19 0 mc:nonIO_6
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Note priority (3rd column) of the auxIO and nonIO is the same as the writers (19) when it should be the same as the readers (0).
See http://review.couchbase.org/#/c/117651/ for the patch which introduced the priority change.
Attachments
Issue Links
- relates to
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MB-36765 15% throughput regression in YCSB Workload A 12vCPU
- Closed