Programmer Think

Watcher is the event monitoring mechanism of zookeeper. Today, let's see what the code of watcher class contains? Watcher Watcher is an interface that defines the process method, which needs to be implemented by a subclass. It represents the method that must be implemented when implementing the watcher interface, that is, defining for processi ...

Next, I went on to analyze the source code of the Watcher related classes. ClientWatchManager public Set<Watcher> materialize(Watcher.Event.KeeperState state, Watcher.Event.EventType type, String path); This interface has only one method and needs to be implemented. This method represents the Watcher collection to be notified whe ...

Distributed applications have a variety of problems.To solve these problems, besides applying some monitoring buried points by yourself, there should be some peripheral systems for active detection and discovery. That's what APM tools do. SkyWalking is an excellent APM application from open source and has become a top-level project for apache. ...

1. hbase integration Mapreduce    in the offline task scenario, MapReduce accesses HBASE data to speed up analysis and expand analysis capabilities.Read data from hbase (result) public class ReadHBaseDataMR { private static final String ZK_KEY = "hbase.zookeeper.quorum"; private static final String ZK_VALUE = "hadoop01:2181,h ...

Curator It is an open-source Zookeeper client of Netflix. Compared with the native client provided by Zookeeper, the cursor has a higher level of abstraction and simplifies the programming of Zookeeper client. Maven dependence   <dependency>     <groupId>org.apache.zookeeper</groupId>     <artifactId>zookeeper</arti ...

dubbo has its own service monitoring server, incubator dubbo OPS development, and github can be downloaded. There are also many local deployment examples on the Internet, so I wondered if I could monitor dubbo's service by myself, so I wrote the following code. In particular, zookeeper's watch mechanism is a one-time trigger. When it is heard t ...

[TOC] Section I Kafka cluster Before inheriting If you are a developer and are not interested in building kafka cluster, you can skip this chapter and look at tomorrow's content directly If you think it's no harm to know more, please keep reading. As a reminder, there are many figures in this chapter Kafka cluster construction Summary The ...

The previous article introduced Hadoop distributed configuration , but designed to be highly available, this time use zookeeper to configure Hadoop highly available. 1. Environmental preparation 1) modify IP 2) modify the mapping of host name and host name and IP address 3) turn off the firewall 4) ssh password free login 5) create hado ...

In many scenarios of distributed system, in order to ensure the final consistency of data, we need many technical solutions to support, such as distributed transactions, distributed locks and so on. Sometimes, we need to ensure that a method can only be executed by the same thread at the same time. In the stand-alone environment, Java actually ...

Links to the original text: http://www.cnblogs.com/JAYIT/p/9645728.html Normally, a service will not only be a client or a server. Generally, microservices are services and services calling each other. So, how to configure them? Nex ...