String ssString = SnapshotDescriptionUtils.toString(expected);
// check to see if the sentinel exists,
// and if the task is complete removes it from the in-progress snapshots map.
SnapshotSentinel handler = removeSentinelIfFinished(this.snapshotHandlers, expected);
// stop tracking "abandoned" handlers
cleanupSentinels();
if (handler == null) {
// If there's no handler in the in-progress map, it means one of the following:
// - someone has already requested the snapshot state
// - the requested snapshot was completed long time ago (cleanupSentinels() timeout)
// - the snapshot was never requested
// In those cases returns to the user the "done state" if the snapshots exists on disk,
// otherwise raise an exception saying that the snapshot is not running and doesn't exist.
if (!isSnapshotCompleted(expected)) {
throw new UnknownSnapshotException("Snapshot " + ssString
+ " is not currently running or one of the known completed snapshots.");
}
// was done, return true;
return true;
}
// pass on any failure we find in the sentinel
try {
handler.rethrowExceptionIfFailed();
} catch (ForeignException e) {
// Give some procedure info on an exception.
String status;
Procedure p = coordinator.getProcedure(expected.getName());
if (p != null) {
status = p.getStatus();
} else {
status = expected.getName() + " not found in proclist " + coordinator.getProcedureNames();
}
throw new HBaseSnapshotException("Snapshot " + ssString + " had an error. " + status, e,
expected);
}
// check to see if we are done
if (handler.isFinished()) {
LOG.debug("Snapshot '" + ssString + "' has completed, notifying client.");
return true;
} else if (LOG.isDebugEnabled()) {
LOG.debug("Snapshoting '" + ssString + "' is still in progress!");
}