The PageWriter has cache buffer so that it doesn't call the Writer until
the cache is almost full. Since the data's length is random, the pending
bytes should be always less than cache buffer size, instead of page
size.
Fix: #16255
Signed-off-by: Wei Fu <fuweid89@gmail.com>
(cherry picked from commit fddd1add52b33649a99d7f756404924138344a10)
Signed-off-by: Wei Fu <fuweid89@gmail.com>
A call file.Sync on OSX doesn't guarantee actual persistence on
physical drive media as the data can be cached in physical drive's
buffers. Hence calls to file.Sync need to be replaced with
fcntl(F_FULLFSYNC).
etcd might generate incomplete proxy config file after a power failure.
It is because we use ioutil.WriteFile. And iotuile.WriteFile does
not call Sync before closing the file.
