/**
* @param region Region to scan
* @throws IOException
*/
protected void scanRegion(final MetaRegion region) throws IOException {
HRegionInterface regionServer = null;
long scannerId = -1L;
LOG.info(Thread.currentThread().getName() + " scanning meta region " +
region.toString());
// Array to hold list of split parents found. Scan adds to list. After
// scan we go check if parents can be removed.
Map<HRegionInfo, Result> splitParents =
new HashMap<HRegionInfo, Result>();
List<byte []> emptyRows = new ArrayList<byte []>();
int rows = 0;
try {
regionServer = master.connection.getHRegionConnection(region.getServer());
Scan s = new Scan().addFamily(HConstants.CATALOG_FAMILY);
// Make this scan do a row at a time otherwise, data can be stale.
s.setCaching(1);
scannerId = regionServer.openScanner(region.getRegionName(), s);
while (true) {
Result values = regionServer.next(scannerId);
if (values == null || values.size() == 0) {
break;
}
HRegionInfo info = master.getHRegionInfo(values.getRow(), values);
if (info == null) {
emptyRows.add(values.getRow());
continue;
}
String serverAddress = getServerAddress(values);
long startCode = getStartCode(values);
// Note Region has been assigned.
checkAssigned(regionServer, region, info, serverAddress, startCode);
if (isSplitParent(info)) {
splitParents.put(info, values);
}
rows += 1;
}
if (rootRegion) {
this.master.regionManager.setNumMetaRegions(rows);
}
} catch (IOException e) {
if (e instanceof RemoteException) {
e = RemoteExceptionHandler.decodeRemoteException((RemoteException) e);
if (e instanceof UnknownScannerException) {
// Reset scannerId so we do not try closing a scanner the other side
// has lost account of: prevents duplicated stack trace out of the
// below close in the finally.
scannerId = -1L;
}
}
throw e;
} finally {
try {
if (scannerId != -1L && regionServer != null) {
regionServer.close(scannerId);
}
} catch (IOException e) {
LOG.error("Closing scanner",
RemoteExceptionHandler.checkIOException(e));
}