Use the path/filepath package instead of the path package. The
path package assumes slash-separated paths, which doesn't work
on Windows. But path/filepath manipulates filename paths in a way
that's compatible across OSes.
Windows requires this lock to be released before the directory is
renamed. But on unix-like operating systems, releasing the lock and
trying to reacquire it immediately can be flaky if a process is forked
around the same time. The file descriptors are marked as close-on-exec
by the Go runtime, but there is a window between the fork and exec where
another process will be holding the lock.
On ReadAll, WAL seeks to the end of the last record in the tail. If the tail did not
end with preallocated space, the decoder would report 0 as the last offset and begin
writing at offset 0 of the tail.
Fixes#4903
File lock interface was more verbose than it needed to be while
simultaneously making it difficult to support systems (e.g., Windows)
that only permit locked writes on a single fd holding the lock.
Backup process should be able to read all WALs until io.EOF to
generate a point-in-time backup.
Our WAL file is append-only. And the backup process will lock all
files before start reading, which can prevent the gc routine from
removing any files in the middle.
ReleaseLockTo should not release the lock on the WAL
segment that is right before the given index. When
restarting etcd, etcd needs to read from the WAL segment
that has a smaller index than the snapshot index.
The correct behavior is that ReleaseLockTo releases
the locks w is holding so that w only holds one lock
that has an index smaller than the given index.
WAL should control the cut logic itself. We want to do falloc to
per allocate the space for a segmented wal file at the beginning
and cut it when it size reaches the limit.
Make raftIndex section to be expected raftIndex of next entry.
It makes filename more intuitive and straight-forward.
The commit also adds comments for filename format.
Using 0xBEEF is annoying in examples because it makes it makes it look
like the user can use ascii or something. In the Procfile use
0x0,0x1,0x2,etc and use 0xBAD0 in test.
