Apache Zookeeper vs etcd3

I have previously written about Distributed Coordination giving an introductory idea on “what is distributed coordination” and “why do we need it?”. When it comes to the implementations of distributed coordination schemes, there are many outstanding systems like apache zookeeper, etcd, consul and hazlecast. Even though some of them are not directly distributed coordination systems,...

Distributed Coordination

How many of you have heard about distributed coordination? I guess not many of you. But you may have heard about distributed computing. Well, distributed coordination is quite similar, but this is only used for coordination purposes. Suppose you have a cluster of nodes and want a convenient mean to communicate among them. Telling each...

Network partitioning in zookeeper

You may know that zookeeper operates as a quorum of zookeeper servers. If two servers cannot talk to each other that means there is a network partitioning problem (one set of servers cannot reach the other servers in different parts of a network). Since we use odd number of servers in the quorum, there will...

Apache Curator in 5 Minutes

First you should build the CuratorFramework instance as follows. Here, the connectStringmeans a comma separated list of ip and port combinations of the zookeeper servers in your ensemble. CuratorFrameworkFactory.Builder builder = CuratorFrameworkFactory.builder() .connectString(connectString) .retryPolicy(new ExponentialBackoffRetry(retryInitialWaitMs, maxRetryCount)) .connectionTimeoutMs(connectionTimeoutMs) .sessionTimeoutMs(sessionTimeoutMs); /* * If authorization information is available, those will be added to the client. NOTE: These auth...