io.ray.streaming.state.strategy.DualStateStoreManager Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.ray.streaming.state.strategy;
import com.google.common.primitives.Longs;
import io.ray.streaming.state.StateException;
import io.ray.streaming.state.StorageRecord;
import io.ray.streaming.state.store.KeyValueStore;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This class define the checkpoint store strategy, which saves two-version data once.
*/
public class DualStateStoreManager extends AbstractStateStoreManager {
private static final Logger LOG = LoggerFactory.getLogger(DualStateStoreManager.class);
public DualStateStoreManager(KeyValueStore> backStore) {
super(backStore);
}
@Override
public void finish(long checkpointId) {
LOG.info("do finish checkpointId:{}", checkpointId);
Map cpStore = new HashMap<>();
for (Entry> entry : frontStore.entrySet()) {
String key = entry.getKey();
StorageRecord value = entry.getValue();
cpStore.put(key, toBytes(value));
}
middleStore.put(checkpointId, cpStore);
frontStore.clear();
}
@Override
public void commit(long checkpointId) {
try {
LOG.info("do commit checkpointId:{}", checkpointId);
Map cpStore = middleStore.get(checkpointId);
if (cpStore == null) {
throw new StateException("why cp store is null");
}
for (Entry entry : cpStore.entrySet()) {
String key = entry.getKey();
byte[] value = entry.getValue();
/**
* 2 is specific key in kv store and indicates that new value
* should be stored with this key after overwriting old value in key 1. i.e.
*
* -2 -1 1 2
* k1 6 5 a b
* k2 9 7 d e
*
* k1's value for checkpoint 5 is a, and b for checkpoint 6.
*/
Map remoteData = super.kvStore.get(key);
if (remoteData == null || remoteData.size() == 0) {
remoteData = new HashMap<>();
remoteData.put(2L, value);
remoteData.put(-2L, Longs.toByteArray(checkpointId));
} else {
long oldBatchId = Longs.fromByteArray(remoteData.get(-2L));
if (oldBatchId < checkpointId) {
//move the old data
remoteData.put(1L, remoteData.get(2L));
remoteData.put(-1L, remoteData.get(-2L));
}
//put the new data here
remoteData.put(2L, value);
remoteData.put(-2L, Longs.toByteArray(checkpointId));
}
super.kvStore.put(key, remoteData);
}
super.kvStore.flush();
} catch (Exception e) {
LOG.error(e.getMessage(), e);
throw new StateException(e);
}
}
@Override
public void rollBack(long checkpointId) {
LOG.info("do rollBack checkpointId:{}", checkpointId);
this.frontStore.clear();
this.middleStore.clear();
this.kvStore.clearCache();
}
@Override
public V get(long checkpointId, String key) {
// get from current cp cache
StorageRecord storageRecord = frontStore.get(key);
if (storageRecord != null) {
return storageRecord.getValue();
}
//get from not commit cp info
List checkpointIds = new ArrayList<>(middleStore.keySet());
Collections.sort(checkpointIds);
for (int i = checkpointIds.size() - 1; i >= 0; i--) {
Map cpStore = middleStore.get(checkpointIds.get(i));
if (cpStore != null) {
if (cpStore.containsKey(key)) {
byte[] cpData = cpStore.get(key);
storageRecord = toStorageRecord(cpData);
return storageRecord.getValue();
}
}
}
try {
Map remoteData = super.kvStore.get(key);
if (remoteData != null) {
for (Entry entry : remoteData.entrySet()) {
if (entry.getKey() > 0) {
StorageRecord tmp = toStorageRecord(entry.getValue());
if (tmp.getCheckpointId() < checkpointId) {
if (storageRecord == null) {
storageRecord = tmp;
} else if (storageRecord.getCheckpointId() < tmp.getCheckpointId()) {
storageRecord = tmp;
}
}
}
}
if (storageRecord != null) {
return storageRecord.getValue();
}
}
} catch (Exception e) {
LOG.error("get checkpointId:" + checkpointId + " key:" + key, e);
throw new StateException(e);
}
return null;
}
@Override
public void ackCommit(long checkpointId) {
LOG.info("do ackCommit checkpointId:{}", checkpointId);
middleStore.remove(checkpointId);
}
}
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