/**
* Creates a new RocksDB backed state and restores from the given backup directory. After
* restoring the backup directory is deleted.
*
* @param keySerializer The serializer for the keys.
* @param namespaceSerializer The serializer for the namespace.
* @param basePath The path on the local system where RocksDB data should be stored.
* @param restorePath The path to a backup directory from which to restore RocksDb database.
*/
protected AbstractRocksDBState(
TypeSerializer<K> keySerializer,
TypeSerializer<N> namespaceSerializer,
File basePath,
String checkpointPath,
String restorePath,
Options options) {
rocksDbPath = new File(basePath, "db" + UUID.randomUUID().toString());
hadoopConfPath = new File(basePath, HADOOP_CONF_NAME);
RocksDB.loadLibrary();
// clean it, this will remove the last part of the path but RocksDB will recreate it
try {
if (rocksDbPath.exists()) {
LOG.warn("Deleting already existing db directory {}.", rocksDbPath);
FileUtils.deleteDirectory(rocksDbPath);
}
} catch (IOException e) {
throw new RuntimeException("Error cleaning RocksDB data directory.", e);
}
try (BackupEngine backupEngine =
BackupEngine.open(Env.getDefault(), new BackupableDBOptions(restorePath + "/"))) {
backupEngine.restoreDbFromLatestBackup(
rocksDbPath.getAbsolutePath(), rocksDbPath.getAbsolutePath(), new RestoreOptions(true));
} catch (RocksDBException | IllegalArgumentException e) {
throw new RuntimeException("Error while restoring RocksDB state from " + restorePath, e);
} finally {
try {
FileUtils.deleteDirectory(new File(restorePath));
} catch (IOException e) {
LOG.error("Error cleaning up local restore directory " + restorePath, e);
}
}
this.keySerializer = requireNonNull(keySerializer);
this.namespaceSerializer = namespaceSerializer;
this.basePath = basePath;
this.checkpointPath = checkpointPath;
if (!basePath.exists()) {
if (!basePath.mkdirs()) {
throw new RuntimeException("Could not create RocksDB data directory.");
}
}
try {
db = RocksDB.open(options, rocksDbPath.getAbsolutePath());
} catch (RocksDBException e) {
throw new RuntimeException("Error while opening RocksDB instance.", e);
}
writeHadoopConfig(hadoopConfPath);
}
@Override
public final KvStateSnapshot<K, N, S, SD, RocksDBStateBackend> snapshot(
final long checkpointId, long timestamp) throws Exception {
final File localBackupPath = new File(basePath, "local-chk-" + checkpointId);
final URI backupUri = new URI(checkpointPath + "/chk-" + checkpointId);
if (!localBackupPath.exists()) {
if (!localBackupPath.mkdirs()) {
throw new RuntimeException("Could not create local backup path " + localBackupPath);
}
}
try (BackupEngine backupEngine =
BackupEngine.open(
Env.getDefault(), new BackupableDBOptions(localBackupPath.getAbsolutePath()))) {
backupEngine.createNewBackup(db);
}
return new AsyncRocksDBSnapshot<>(localBackupPath, backupUri, checkpointId, this);
}