There's a time window after we call RotateFile() where autofile#index+1
does not exist. It will be created during the next call to Write(). BUT
if somebody calls NewReader() before Write(), it will fail with "open
/tmp/wal#index+1/wal: no such file or directory"
We must create file (either by calling gr.Head.openFile() or directly)
during NewReader() to ensure read calls succeed.
Closes#2538
* fix Group.RotateFile need call Flush() before rename. #2428
* fix some review issue. #2428
refactor Group's config: replace setting member with initial option
* fix a handwriting mistake
* fix a time window error between rename and write.
* fix a syntax mistake.
* change option name Get_ to With_
* fix review issue
* fix review issue
1) no need to stop the ticker in createTestGroup() method
2) now there is a symmetry - we start the ticker in OnStart(), we stop it
in OnStop()
Refs #2072
Anton Kaliaev
goolAdapter
Ethan Buchman
Dev Ojha