Curator Framework exception processing and best practice
Curator Framework exception processing and best practice
Curator Framework is a Java client library for Apache Zookeeper to simplify interaction with Zookeeper.When using Curator Framework, good abnormal treatment and best practice are very important to ensure the stability and reliability of the application.This article will introduce abnormal processing in Curator Framework and provide some example code for the best practice.
Abnormal treatment
1. Abnormal classification: The abnormalities in Curator Framework are mainly divided into two types: CuratorConnectionLossexception and Curatorexception.When the Zookeeper is lost, the CuratorConnectionLossexception will be thrown.Other abnormalities related to Zookeeper are thrown out of the Curatorexception.
2. Abnormal processing strategy: When dealing with abnormalities in Curator Framework, the following are some common processing strategies:
-The abnormal retry: For CuratorConnectionLossexception, you can choose to re -connect and try again.You can use Curator's RetryPolicy to define the retry strategy and pass it to the CuratorFramework instance.
-Chide log records: For all abnormal conditions, it is recommended to record anomalous information for failure to eliminate and monitor.Use the appropriate log frame (such as SLF4J) to record abnormal information.
-Curator Framework provides an abnormal processing recovery mechanism for developers to handle abnormalities and take appropriate measures.You can register an abnormal processing target through the GetunhandleDererLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorLorl, and processed.
-Onomiconia: When using the API method of using Curator Fermework, you can choose to spread the abnormality to the caller to let the caller handle abnormalities.You can also choose to capture abnormalities and return appropriate results.
Best Practices
1. Use CuratorFramework instance: It is recommended to set the CuratorFRAMEWORK instance to a single example of the application and repeat it in the entire life cycle of the application.This can reduce the complexity of resource consumption and connection management.
public class CuratorFrameworkSingleton {
private static CuratorFramework curatorFramework;
public static CuratorFramework getInstance() {
if (curatorFramework == null) {
curatorFramework = CuratorFrameworkFactory.newClient("localhost:2181", new ExponentialBackoffRetry(1000, 3));
curatorFramework.start();
}
return curatorFramework;
}
}
2. Use node monitor: Curator Framework provides node monitoring (NodeCache, PathchildrenCache, TreeCache), which can monitor the changes in nodes.Using node listeners can obtain changes in nodes in real time and take corresponding operations.
CuratorFramework curatorFramework = CuratorFrameworkSingleton.getInstance();
PathChildrenCache pathChildrenCache = new PathChildrenCache(curatorFramework, "/example-path", true);
pathChildrenCache.getListenable().addListener((client, event) -> {
if (event.getType() == PathChildrenCacheEvent.Type.CHILD_ADDED) {
// Node adding event processing logic
} else if (event.getType() == PathChildrenCacheEvent.Type.CHILD_REMOVED) {
// Node delete the processing logic of the event
}
});
pathChildrenCache.start();
3. Use distributed locks: Curator Framework provides distributed locks (InterprocessMutex, InterprocessSSEMAPHOREMUTEX, InterprocessReadwriteLock) to achieve mutually exclusive and synchronization in a distributed environment.Use a distributed lock to ensure that shared resources are used safely between multiple nodes.
CuratorFramework curatorFramework = CuratorFrameworkSingleton.getInstance();
InterProcessMutex lock = new InterProcessMutex(curatorFramework, "/example-lock");
try {
if (lock.acquire(5, TimeUnit.SECONDS)) {
// Get the logical operation after the lock
} else {
// The processing logic of not obtaining the lock
}
} catch (Exception e) {
// Abnormal processing logic
} finally {
try {
lock.release();
} catch (Exception e) {
// The processing logic of unlocking failure
}
}
Through good abnormal processing and following the best practice, you can better use the functions and characteristics of Curator Framework to ensure the stability and reliability of the application.During the development process, the appropriate abnormal treatment strategy and best practice should also be selected according to actual needs and scenes.
