WL#9631: Change InnoDB IO Defaults - innodb_flush_neighbors
Affects: Server-8.0 — Status: Complete — Priority: Medium
Since fast IO (SSDs) is now the default for deployment, we should flip the default of flush_neighbors to be disabled. This disables merging which may have a negative impact on performance. In summary: innodb_flush_neighbors=0 Concerns/Investigation ---------------------- SYS-QA will verify that disabling innodb_flush_neighbors by default, doesn't have performance impact. Upgrade Story ------------- This new default changes MySQL to cater for SSDs and fast storage devices by default. We expect that for the majority of users, this will result in a small performance gain. Users who are using slower hard drives may see a performance loss, and are encouraged to revert to the previous defaults by setting innodb_flush_neighbors=1.
FR-1) The compiled default value of innodb_flush_neighbors changed from 1 to 0. NFR-1) Any changes required to MTR tests. NFR1) Performance should actually be better on fast IO systems with flush-neighbors. It is expected that performance may drop on slow IO systems.
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