* @throws IOException
*/
public void restoreSnapshot(SnapshotDescription reqSnapshot) throws IOException {
FileSystem fs = master.getMasterFileSystem().getFileSystem();
Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(reqSnapshot, rootDir);
MasterCoprocessorHost cpHost = master.getCoprocessorHost();
// check if the snapshot exists
if (!fs.exists(snapshotDir)) {
LOG.error("A Snapshot named '" + reqSnapshot.getName() + "' does not exist.");
throw new SnapshotDoesNotExistException(reqSnapshot);
}
// read snapshot information
SnapshotDescription fsSnapshot = SnapshotDescriptionUtils.readSnapshotInfo(fs, snapshotDir);
HTableDescriptor snapshotTableDesc = FSTableDescriptors.getTableDescriptor(fs, snapshotDir);
String tableName = reqSnapshot.getTable();
// stop tracking completed restores
cleanupRestoreSentinels();
// Execute the restore/clone operation
if (MetaReader.tableExists(master.getCatalogTracker(), tableName)) {
if (master.getAssignmentManager().getZKTable().isEnabledTable(fsSnapshot.getTable())) {
throw new UnsupportedOperationException("Table '" +
fsSnapshot.getTable() + "' must be disabled in order to perform a restore operation.");
}
// call coproc pre hook
if (cpHost != null) {
cpHost.preRestoreSnapshot(reqSnapshot, snapshotTableDesc);
}
restoreSnapshot(fsSnapshot, snapshotTableDesc);
LOG.info("Restore snapshot=" + fsSnapshot.getName() + " as table=" + tableName);
if (cpHost != null) {
cpHost.postRestoreSnapshot(reqSnapshot, snapshotTableDesc);
}
} else {
HTableDescriptor htd = RestoreSnapshotHelper.cloneTableSchema(snapshotTableDesc,
Bytes.toBytes(tableName));
if (cpHost != null) {
cpHost.preCloneSnapshot(reqSnapshot, htd);
}
cloneSnapshot(fsSnapshot, htd);
LOG.info("Clone snapshot=" + fsSnapshot.getName() + " as table=" + tableName);
if (cpHost != null) {
cpHost.postCloneSnapshot(reqSnapshot, htd);
}
}
}