Springboot2（29）集成zookeeper的增删改查、节点监听、分布式读写锁、分布式计数器
源码地址
springboot2教程系列
实现zookeeper节点的增删改查、节点监听、分布式读写锁、分布式计数器
添加依赖
UTF-8
1.8
3.4.8
2.11.1
org.apache.zookeeper
zookeeper
${zookeeper.version}
org.slf4j
slf4j-log4j12
org.slf4j
slf4j-api
org.apache.curator
curator-recipes
${curator.version}
ZkClient(curator)
这里使用的是curator，curator是对zookeeper的简单封装，提供了一些集成的方法，或者是提供了更优雅的api
/**
* zookeeper客户端
*/
@Data
@Slf4j
public class ZkClient {
private final Logger logger = LoggerFactory.getLogger(this.getClass());
private CuratorFramework client;
public TreeCache cache;
private ZookeeperProperties zookeeperProperties;
public ZkClient(ZookeeperProperties zookeeperProperties){
this.zookeeperProperties = zookeeperProperties;
}
/**
* 初始化zookeeper客户端
*/
public void init() {
try{
RetryPolicy retryPolicy = new ExponentialBackoffRetry(zookeeperProperties.getBaseSleepTimeMs(),
zookeeperProperties.getMaxRetries());
Builder builder = CuratorFrameworkFactory.builder()
.connectString(zookeeperProperties.getServer()).retryPolicy(retryPolicy)
.sessionTimeoutMs( zookeeperProperties.getSessionTimeoutMs())
.connectionTimeoutMs( zookeeperProperties.getConnectionTimeoutMs())
.namespace( zookeeperProperties.getNamespace());
if(StringUtils.isNotEmpty( zookeeperProperties.getDigest())){
builder.authorization("digest", zookeeperProperties.getDigest().getBytes("UTF-8"));
builder.aclProvider(new ACLProvider() {
@Override
public List<ACL> getDefaultAcl() {
return ZooDefs.Ids.CREATOR_ALL_ACL;
}
@Override
public List<ACL> getAclForPath(final String path) {
return ZooDefs.Ids.CREATOR_ALL_ACL;
}
});
}
client = builder.build();
client.start();
initLocalCache("/test");
// addConnectionStateListener();
client.getConnectionStateListenable().addListener(new ConnectionStateListener() {
public void stateChanged(CuratorFramework client, ConnectionState state) {
if (state == ConnectionState.LOST) {
//连接丢失
logger.info("lost session with zookeeper");
} else if (state == ConnectionState.CONNECTED) {
//连接新建
logger.info("connected with zookeeper");
} else if (state == ConnectionState.RECONNECTED) {
logger.info("reconnected with zookeeper");
}
}
});
}catch(Exception e){
e.printStackTrace();
}
}
/**
* 初始化本地缓存
* @param watchRootPath
* @throws Exception
*/
private void initLocalCache(String watchRootPath) throws Exception {
cache = new TreeCache(client, watchRootPath);
TreeCacheListener listener = (client1, event) ->{
log.info("event:" + event.getType() +
" |path:" + (null != event.getData() ? event.getData().getPath() : null));
if(event.getData()!=null && event.getData().getData()!=null){
log.info("发生变化的节点内容为：" + new String(event.getData().getData()));
}
// client1.getData().
};
cache.getListenable().addListener(listener);
cache.start();
}
public void stop() {
client.close();
}
public CuratorFramework getClient() {
return client;
}
/**
* 创建节点
* @param mode 节点类型
* 1、PERSISTENT 持久化目录节点，存储的数据不会丢失。
* 2、PERSISTENT_SEQUENTIAL顺序自动编号的持久化目录节点，存储的数据不会丢失
* 3、EPHEMERAL临时目录节点，一旦创建这个节点的客户端与服务器端口也就是session 超时，这种节点会被自动删除
*4、EPHEMERAL_SEQUENTIAL临时自动编号节点，一旦创建这个节点的客户端与服务器端口也就是session 超时，这种节点会被自动删除，并且根据当前已近存在的节点数自动加 1，然后返回给客户端已经成功创建的目录节点名。
* @param path 节点名称
* @param nodeData 节点数据
*/
public void createNode(CreateMode mode, String path , String nodeData) {
try {
//使用creatingParentContainersIfNeeded()之后Curator能够自动递归创建所有所需的父节点
client.create().creatingParentsIfNeeded().withMode(mode).forPath(path,nodeData.getBytes("UTF-8"));
} catch (Exception e) {
logger.error("注册出错", e);
}
}
/**
* 创建节点
* @param mode 节点类型
* 1、PERSISTENT 持久化目录节点，存储的数据不会丢失。
* 2、PERSISTENT_SEQUENTIAL顺序自动编号的持久化目录节点，存储的数据不会丢失
* 3、EPHEMERAL临时目录节点，一旦创建这个节点的客户端与服务器端口也就是session 超时，这种节点会被自动删除
* 4、EPHEMERAL_SEQUENTIAL临时自动编号节点，一旦创建这个节点的客户端与服务器端口也就是session 超时，这种节点会被自动删除，并且根据当前已近存在的节点数自动加 1，然后返回给客户端已经成功创建的目录节点名。
* @param path 节点名称
*/
public void createNode(CreateMode mode,String path ) {
try {
//使用creatingParentContainersIfNeeded()之后Curator能够自动递归创建所有所需的父节点
client.create().creatingParentsIfNeeded().withMode(mode).forPath(path);
} catch (Exception e) {
logger.error("注册出错", e);
}
}
/**
* 删除节点数据
*
* @param path
*/
public void deleteNode(final String path) {
try {
deleteNode(path,true);
} catch (Exception ex) {
log.error("{}",ex);
}
}
/**
* 删除节点数据
* @param path
* @param deleteChildre 是否删除子节点
*/
public void deleteNode(final String path,Boolean deleteChildre){
try {
if(deleteChildre){
//guaranteed()删除一个节点，强制保证删除,
// 只要客户端会话有效，那么Curator会在后台持续进行删除操作，直到删除节点成功
client.delete().guaranteed().deletingChildrenIfNeeded().forPath(path);
}else{
client.delete().guaranteed().forPath(path);
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 设置指定节点的数据
* @param path
* @param datas
*/
public void setNodeData(String path, byte[] datas){
try {
client.setData().forPath(path, datas);
}catch (Exception ex) {
log.error("{}",ex);
}
}
/**
* 获取指定节点的数据
* @param path
* @return
*/
public byte[] getNodeData(String path){
Byte[] bytes = null;
try {
if(cache != null){
ChildData data = cache.getCurrentData(path);
if(data != null){
return data.getData();
}
}
client.getData().forPath(path);
return client.getData().forPath(path);
}catch (Exception ex) {
log.error("{}",ex);
}
return null;
}
/**
* 获取数据时先同步
* @param path
* @return
*/
public byte[] synNodeData(String path){
client.sync();
return getNodeData( path);
}
/**
* 判断路径是否存在
*
* @param path
* @return
*/
public boolean isExistNode(final String path) {
client.sync();
try {
return null != client.checkExists().forPath(path);
} catch (Exception ex) {
return false;
}
}
/**
* 获取节点的子节点
* @param path
* @return
*/
public List<String> getChildren(String path) {
List<String> childrenList = new ArrayList<>();
try {
childrenList = client.getChildren().forPath(path);
} catch (Exception e) {
logger.error("获取子节点出错", e);
}
return childrenList;
}
/**
* 随机读取一个path子路径, "/"为根节点对应该namespace
* 先从cache中读取，如果没有，再从zookeeper中查询
* @param path
* @return
* @throws Exception
*/
public String getRandomData(String path) {
try{
Map<String,ChildData> cacheMap = cache.getCurrentChildren(path);
if(cacheMap != null && cacheMap.size() > 0) {
logger.debug("get random value from cache,path="+path);
Collection<ChildData> values = cacheMap.values();
List<ChildData> list = new ArrayList<>(values);
Random rand = new Random();
byte[] b = list.get(rand.nextInt(list.size())).getData();
return new String(b,"utf-8");
}
if(isExistNode(path)) {
logger.debug("path [{}] is not exists,return null",path);
return null;
} else {
logger.debug("read random from zookeeper,path="+path);
List<String> list = client.getChildren().forPath(path);
if(list == null || list.size() == 0) {
logger.debug("path [{}] has no children return null",path);
return null;
}
Random rand = new Random();
String child = list.get(rand.nextInt(list.size()));
path = path + "/" + child;
byte[] b = client.getData().forPath(path);
String value = new String(b,"utf-8");
return value;
}
}catch(Exception e){
log.error("{}",e);
}
return null;
}
/**
* 可重入共享锁 -- Shared Reentrant Lock
* @param lockPath
* @param time
* @param dealWork 获取
* @return
*/
public Object getSRLock(String lockPath,long time, SRLockDealCallback<?> dealWork){
InterProcessMutex lock = new InterProcessMutex(client, lockPath);
try {
if (!lock.acquire(time, TimeUnit.SECONDS)) {
log.error("get lock fail:{}", " could not acquire the lock");
return null;
}
log.debug("{} get the lock",lockPath);
Object b = dealWork.deal();
return b;
}catch(Exception e){
log.error("{}", e);
}finally{
try {
lock.release();
} catch (Exception e) {
//log.error("{}",e);
}
}
return null;
}
/**
* 获取读写锁
* @param path
* @return
*/
public InterProcessReadWriteLock getReadWriteLock(String path){
InterProcessReadWriteLock readWriteLock = new InterProcessReadWriteLock(client, path);
return readWriteLock;
}
/**
* 在注册监听器的时候，如果传入此参数，当事件触发时，逻辑由线程池处理
*/
ExecutorService pool = Executors.newFixedThreadPool(2);
/**
* 监听数据节点的变化情况
* @param watchPath
* @param listener
*/
public void watchPath(String watchPath,TreeCacheListener listener){
// NodeCache nodeCache = new NodeCache(client, watchPath, false);
TreeCache cache = new TreeCache(client, watchPath);
cache.getListenable().addListener(listener,pool);
try {
cache.start();
} catch (Exception e) {
e.printStackTrace();
}
}
}
配置文件
zookeeper.enabled: true
#zookeeper.server: 47.106.106.53:9036,47.106.106.53:9037,47.106.106.53:9038
zookeeper.server: 10.10.2.137:2181,10.10.2.138:2181,10.10.2.139:2181
zookeeper.namespace: demo
zookeeper.digest: rt:rt #zkCli.sh acl 命令 addauth digest mpush
zookeeper.sessionTimeoutMs: 1000 #会话超时时间，单位为毫秒，默认60000ms,连接断开后，其它客户端还能请到临时节点的时间
zookeeper.connectionTimeoutMs: 6000 #连接创建超时时间，单位为毫秒
zookeeper.maxRetries: 3 #最大重试次数
zookeeper.baseSleepTimeMs: 1000 #初始sleep时间 ,毫秒
程序会创建节点demo为namespace，之后所有增删改查的操作都这节点下完成
Controller层方法
@Api(tags="zookeeper基本操作")
@RequestMapping("/zk")
@RestController
@Slf4j
public class ZookeeperController {
@Autowired
private ZkClient zkClient;
@Autowired
private ZkClient zkClientTest;
/**
* 创建节点
* @param type
* @param znode
* @return
*/
@ApiOperation(value = "创建节点",notes = "在命名空间下创建节点")
@ApiImplicitParams({
@ApiImplicitParam(name ="type",value = "节点类型:
0 持久化节点
1 临时节点
2 持久顺序节点
3 临时顺序节点",
allowableValues = "0,1,2,3",defaultValue="3",paramType = "path",required = true,dataType = "Long"),
@ApiImplicitParam(name ="znode",value = "节点名称",paramType = "path",required = true,dataType = "String"),
@ApiImplicitParam(name ="nodeData",value = "节点数据",paramType = "body",dataType = "String")
})
@RequestMapping(value = "/create/{type}/{znode}",method=RequestMethod.POST)
private String create(@PathVariable Integer type,@PathVariable String znode,@RequestBody String nodeData){
znode = "/" + znode;
try {
zkClient.createNode(CreateMode.fromFlag(type),znode,nodeData);
} catch (KeeperException e) {
e.printStackTrace();
}
return znode;
}
/**
* 设置节点数据
* @param znode
* @return
*/
@ApiOperation(value = "设置节点数据",notes = "设置节点数据")
@ApiImplicitParams({
@ApiImplicitParam(name ="znode",value = "节点名称",paramType = "body",required = true,dataType = "String"),
@ApiImplicitParam(name ="nodeData",value = "节点数据",paramType = "query",required = true,dataType = "String")
})
@RequestMapping(value = "/update",method=RequestMethod.POST)
public String update(@RequestBody String znode,@RequestParam String nodeData){
znode = "/" + znode;
zkClient.setNodeData(znode,nodeData.getBytes());
return "sucess";
}
@ApiOperation(value = "删除节点",notes = "删除节点")
@ApiImplicitParams({
@ApiImplicitParam(name ="znode",value = "节点名称",paramType = "query",required = true,dataType = "String")
})
@RequestMapping(value = "/delete",method=RequestMethod.GET)
public String delete(@RequestParam String znode){
znode = "/" + znode;
zkClient.deleteNode(znode);
return "success";
}
@ApiOperation(value = "查找节点的内容",notes = "查找节点的内容")
@ApiImplicitParams({
@ApiImplicitParam(name ="znode",value = "节点名称",paramType = "body",required = true,dataType = "String")
})
@RequestMapping(value = "/find",method=RequestMethod.POST)
public String find(@RequestBody String znode){
znode = "/" + znode;
byte[] b = zkClient.getNodeData(znode);
return new String(b);
}
/**
* 给节点添加读写锁
* @param znode
* @return
*/
@ApiOperation(value = "添加读写锁",notes = "写锁跟读锁互斥,读锁跟读锁共享")
@ApiImplicitParams({
@ApiImplicitParam(name ="lockType",value = "锁类型:
0 写锁
1 读锁",
allowableValues = "0,1",defaultValue="0",paramType = "query",required = true,dataType = "Long"),
@ApiImplicitParam(name ="znode",value = "节点名称",paramType = "query",required = true,dataType = "String")
})
@RequestMapping(value = "/writeLock",method=RequestMethod.GET)
public String readLock(@RequestParam Integer lockType,@RequestParam String znode){
znode = "/" + znode;
InterProcessReadWriteLock readWriteLock = zkClient.getReadWriteLock(znode);
InterProcessMutex writeLock = readWriteLock.writeLock();
InterProcessMutex readLock = readWriteLock.readLock();
Runnable writeRunnable = ()->{
try {
System.out.println("------write lock-----------");
writeLock.acquire();
System.out.println("write acquire");
Thread.sleep(10_000);
System.out.println("write release");
writeLock.release();
} catch (Exception e) {
e.printStackTrace();
}
};
Runnable readRunnable = ()->{
try {
System.out.println("-------read lock----------");
readLock.acquire();
System.out.println("read acquire");
Thread.sleep(20_000);
System.out.println("read release");
readLock.release();
} catch (Exception e) {
e.printStackTrace();
}
};
if(lockType == 0 ){
new Thread(writeRunnable).start();
}else if(lockType == 1){
new Thread(readRunnable).start();
}
return "success";
}
/**
* 监听节点
* @param znode
* @return
*/
@ApiOperation(value = "监听节点",notes = "监控整个树上的所有节点")
@ApiImplicitParams(
@ApiImplicitParam(name ="znode",value = "节点名称",paramType = "body",required = true,dataType = "String")
)
@RequestMapping(value="/watchPath",method=RequestMethod.POST)
public String watchPath(@RequestBody String znode){
znode = "/" + znode;
zkClient.watchPath(znode,(client1, event) ->{
log.info("event:" + event.getType() +
" |path:" + (null != event.getData() ? event.getData().getPath() : null));
if(event.getData()!=null && event.getData().getData()!=null){
log.info("发生变化的节点内容为：" + new String(event.getData().getData()));
}
});
return "success";
}
/**
* 测试计算器
* 并发越高耗时越长
* 要自己实现获取锁失败重试
* @return
*/
@ApiOperation(value = "模拟分布式计数器",notes = "模拟分布式计数器")
@RequestMapping(value="/counter",method=RequestMethod.POST)
public String counter(@RequestBody String znode){
SharedCount baseCount = new SharedCount(zkClientTest.getClient(), znode, 0);
try {
baseCount.start();
//生成线程池
ExecutorService executor = Executors.newCachedThreadPool();
Consumer<SharedCount> consumer = (SharedCount count) -> {
try {
List<Callable<Boolean>> callList = new ArrayList<>();
Callable<Boolean> call = () -> {
boolean result = false;
try {
Long time = System.currentTimeMillis();
while(!result){
VersionedValue<Integer> oldVersion = baseCount.getVersionedValue();
int newCnt = oldVersion.getValue() + 1;
result = baseCount.trySetCount(oldVersion, newCnt);
if(System.currentTimeMillis()-time>10_000||result){
break;
}
TimeUnit.MILLISECONDS.sleep(new Random().nextInt(100)+1);
}
} catch (Exception e) {
}
return result;
};
//5个线程
for (int i = 0; i < 100; i++) {
callList.add(call);
}
List<Future<Boolean>> futures = executor.invokeAll(callList);
} catch (Exception e) {
}
};
//测试分布式int类型的计数器
consumer.accept(baseCount);
System.out.println("final cnt : " + baseCount.getCount());
} catch (Exception e) {
e.printStackTrace();
}
return "success："+baseCount.getCount();
}
/**
* DistributedAtomicLong计数器可以自己设置重试的次数与间隔
* 并发越高耗时越长
* 要自己实现获取锁失败重试
*/
@ApiOperation(value = "模拟分布式计数器2",notes = "模拟分布式计数器2")
@RequestMapping(value="/counter2",method=RequestMethod.POST)
public String distributedCount(@RequestBody String znode) throws Exception {
DistributedAtomicLong distributedAtomicLong = new DistributedAtomicLong(
zkClientTest.getClient(), znode, new RetryNTimes(10, 30));
//生成线程池
ExecutorService executor = Executors.newCachedThreadPool();
Consumer<DistributedAtomicLong> consumer = (DistributedAtomicLong count) -> {
try {
List<Callable<Boolean>> callList = new ArrayList<>();
Callable<Boolean> call = () -> {
boolean result = false;
try {
AtomicValue<Long> val = count.increment();
System.out.println("old cnt: "+val.preValue()+" new cnt : "+ val.postValue()+" result:"+val.succeeded());
result = val.succeeded();
} catch (Exception e) {
} finally {
}
return result;
};
//5个线程
for (int i = 0; i < 500; i++) {
callList.add(call);
}
List<Future<Boolean>> futures = executor.invokeAll(callList);
} catch (Exception e) {
}
};
consumer.accept(distributedAtomicLong);
return "success："+distributedAtomicLong.get().postValue();
}
/**
*
* @return
* @throws KeeperException
*/
@ApiOperation(value = "模拟服务注册和随机获取服务",notes = "模拟服务注册和随机获取服务")
@RequestMapping(value="/serviceRegistry",method=RequestMethod.POST)
public String serviceRegistry() throws KeeperException {
//服务注册
zkClient.createNode(CreateMode.fromFlag(1),"/test/hello_service1","http://1270.0.1:8001/");
zkClient.createNode(CreateMode.fromFlag(1),"/test/hello_service2","http://1270.0.1:8002/");
zkClient.createNode(CreateMode.fromFlag(1),"/test/hello_service3","http://1270.0.1:8003/");
return zkClient.getRandomData("/test");
}
}
测试
测试地址：http://127.0.0.1:8080/swagger-ui.html
读写锁测试
在界面发送两次写锁
后面打印
2018-12-29 11:45:27.214 INFO 53332 --- [ Thread-24] : ------write lock-----------
2018-12-29 11:45:27.242 INFO 53332 --- [ Thread-24] : write acquire
2018-12-29 11:45:30.870 INFO 53332 --- [ Thread-25] : ------write lock-----------
2018-12-29 11:45:37.243 INFO 53332 --- [ Thread-24] : write release
2018-12-29 11:45:37.276 INFO 53332 --- [ Thread-25] : write acquire
2018-12-29 11:45:47.276 INFO 53332 --- [ Thread-25] : write release
可以看出写锁是互斥的，另外写锁跟读锁也是互斥的，读锁跟读锁之间是共享的（自行测试）
计数器测试
修改方法中的线程个数，会发现并发越大，计数器执行时间越长，而且很大可能数据不准确。所以不适用于高并发的场景。
