* Fix bug with WAL watcher and Live Reader metrics usage.
Calling NewXMetrics when creating a Watcher or LiveReader results in a
registration error, which we're ignoring, and as a result other than the
first Watcher/Reader created, we had no metrics for either. So we would
only have metrics like Watcher Records Read for the first remote write
config in a users config file.
Signed-off-by: Callum Styan <callumstyan@gmail.com>
The WAL Watcher replays a checkpoint after it is created in order to
garbage collect series that no longer exist in the WAL. Currently the
garbage collection process is done serially with reading from the tip of
the WAL which can cause large delays in writing samples to remote
storage just after compaction occurs.
This also fixes a memory leak where dropped series are not cleaned up as
part of the SeriesReset process.
Signed-off-by: Chris Marchbanks <csmarchbanks@gmail.com>
