After the amount of
This is done because the OS will otherwise buffer all the writes, and when a fsync is really needed, it can take a lot of time...
Originally this parameter was hard coded. Now it defaults to 4 Mbyte.
The parameter DiskSyncSize is related to the parameters NoOfDiskPagesToDiskAfterRestartTUP and NoOfDiskPagesToDiskAfterRestartACC which are deprecated right now. It does NOT replace the parameter TimeBetweenLocalCheckpoint.
This parameter should not be changed on any OS (with reasonable settings). With ODIRECT it is not used at all.
Thanks to Jonas for the help.
2 comments:
I guess it is related to DiskCheckpointSpeed nowadays (>= 5.1 ).
johan (johanandersson.blogspot.com)
According to the information I have, it was added in 5.1.12, not 5.1.23.
In any case, it is available in all recent MySQL Cluster NDB 6.2 and 6.3 releases.
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