This is useful for debugging of buffer flush issue.
I set default value is 5.0. This is good for local destination but 5.0 seems small for cloud based services.
Should we set large value for default setting?
This patch is for v0.12 but support this feature in v0.14 is also good.
Add slow_flush_threshold parameter
It is also good. I refer long_query_time in mysql first.
Adding log is no problem for me.
Rename to slow_flush_log_threshold
Change to larger value to suppress warning for external services
Rename and change default values.
After test passed, I will merge this patch.
Could you create a pull-request for master branch before merging?
I want to make it sure to port this feature to v0.14.
Add : to log