Talking about distributed storage from ES, mongodb, redis and rocketmq

Redis

redis Partitioned cluster is a whole cluster composed of several small clusters supporting automatic master-slave failover gossip Protocol communication , Decentralized architecture , The client entry depends on the client API

ES

ES There is no concept of slave nodes , Only the concept of main partition and sub partition , A data node has both primary and secondary partitions , Unique through the cluster master Unified management , Centralized architecture , The client entry is the coordination node

MongoDB

MongoDB There are three kinds of nodes ,Config Server,Shard Server,Route Server,Config Server similar ES Of master, Centralized architecture ,Shard Server With the concept of master node and slave node , and Redis similar ,Route Server yes guanli Client unified portal , similar ES Coordination node of , comparison ES,MongoDB The architecture of is simpler

RocketMQ

nameserver No state , Every broker The cluster has a master node , Several slave nodes ,broker Clusters are independent of each other , similar Redis and MongoDB, You can read the previous article RocketMQ Capacity expansion and contraction solution , The client entry is nameserver, Why? nameserver Can be stateless ？ because nameserver Don't look like ES Of master and MongoDB Of Config Server equally , Uniformly manage the data distribution of the whole cluster ,RocketMQ The unit of data is message , Exist in topic Under a queue , also broker What do you have topic It's all set by the user ,nameserver The role of is broker Report what you currently have topic, queue , Clients are producers and consumers nameserver query-specified topic In what broker On , So as to consume