Java Checkpoint类代码示例

import org.rocksdb.Checkpoint; //导入依赖的package包/类
/**
 * Flush the data in memtable of RocksDB into disk, and then create checkpoint
 * 
 * @param batchId
 */
@Override
public void checkpoint(long batchId) {
    long startTime = System.currentTimeMillis();
    try {
        rocksDb.flush(new FlushOptions());
        Checkpoint cp = Checkpoint.create(rocksDb);
        cp.createCheckpoint(getLocalCheckpointPath(batchId));
    } catch (RocksDBException e) {
        LOG.error("Failed to create checkpoint for batch-" + batchId, e);
        throw new RuntimeException(e.getMessage());
    }

    if (JStormMetrics.enabled)
        rocksDbFlushAndCpLatency.update(System.currentTimeMillis() - startTime);
}
 

import org.rocksdb.Checkpoint; //导入依赖的package包/类
void takeSnapshot() throws Exception {

			final long lastCompletedCheckpoint;

			// use the last completed checkpoint as the comparison base.
			synchronized (stateBackend.materializedSstFiles) {
				lastCompletedCheckpoint = stateBackend.lastCompletedCheckpointId;
				baseSstFiles = stateBackend.materializedSstFiles.get(lastCompletedCheckpoint);
			}

			LOG.trace("Taking incremental snapshot for checkpoint {}. Snapshot is based on last completed checkpoint {} " +
				"assuming the following (shared) files as base: {}.", checkpointId, lastCompletedCheckpoint, baseSstFiles);

			// save meta data
			for (Map.Entry<String, Tuple2<ColumnFamilyHandle, RegisteredKeyedBackendStateMetaInfo<?, ?>>> stateMetaInfoEntry
				: stateBackend.kvStateInformation.entrySet()) {
				stateMetaInfoSnapshots.add(stateMetaInfoEntry.getValue().f1.snapshot());
			}

			// save state data
			backupPath = new Path(stateBackend.instanceBasePath.getAbsolutePath(), "chk-" + checkpointId);

			LOG.trace("Local RocksDB checkpoint goes to backup path {}.", backupPath);

			backupFileSystem = backupPath.getFileSystem();
			if (backupFileSystem.exists(backupPath)) {
				throw new IllegalStateException("Unexpected existence of the backup directory.");
			}

			// create hard links of living files in the checkpoint path
			Checkpoint checkpoint = Checkpoint.create(stateBackend.db);
			checkpoint.createCheckpoint(backupPath.getPath());
		}
 

import org.rocksdb.Checkpoint; //导入依赖的package包/类
private static void rocksDbTest(RocksDB db, List<ColumnFamilyHandle> handlers) {
    try {
        ColumnFamilyHandle handler1 = null;
        ColumnFamilyHandle handler2 = null;
        if (handlers.size() > 0) {
            // skip default column family
            handler1 = handlers.get(1);
            handler2 = handlers.get(2);
        } else {
            handler1 = db.createColumnFamily(new ColumnFamilyDescriptor("test1".getBytes()));
            handler2 = db.createColumnFamily(new ColumnFamilyDescriptor("test2".getBytes()));
        }
        int startValue1 = getStartValue(db, handler1);
        int startValue2 = getStartValue(db, handler2);;

        Checkpoint cp = Checkpoint.create(db);
   
        if (isCompaction) {
            db.compactRange();
            LOG.info("Compaction!");
        }

        long flushWaitTime = System.currentTimeMillis() + flushInterval;
        for (int i = 0; i < putNum || putNum == -1; i++) {
            db.put(handler1, String.valueOf(i % 1000).getBytes(), String.valueOf(startValue1 + i).getBytes());
            db.put(handler2, String.valueOf(i % 1000).getBytes(), String.valueOf(startValue2 + i).getBytes());
            if (isFlush && flushWaitTime <= System.currentTimeMillis()) {
                db.flush(new FlushOptions());
                if (isCheckpoint) {
                    cp.createCheckpoint(cpPath + "/" + i);
                }
                flushWaitTime = System.currentTimeMillis() + flushInterval;
            }
        }
    } catch (RocksDBException e) {
        LOG.error("Failed to put or flush", e);
    }
}