The comparison between MongoDB and Redis

Both MongoDB and Redis are NoSQL, using structured data storage. There are some differences between the two in the usage scene, which is mainly due to the process of the memory mapping, and the persistence processing method is different.

MongoDB recommended cluster deployment, more considering the cluster scenario, Redis is more emphasis on process sequential write, although the support cluster, but also limited to the master-slave mode.

Compare indicators	MongoDB (v2.4.9)	Redis (v2.4.17)	Comparison notes
Implementation language	C++	C + +	-
Agreement	BSON, Custom Binary	Class Telnet	-
Performance	Memory dependent, higher TPS	Memory dependent, TPS very high	Redis is better than MongoDB
operability	Rich data expression, index, most similar to relational database, support rich query statement	Data-rich, less IO	MongoDB is better than Redis
Memory and Storage	Suitable for large data volume storage, dependent on system virtual memory, image file storage, high memory consumption ratio, the official recommended independent deployment in 64-bit system	REDIS2.0 supports virtual memory features (VMS) Beyond physical memory limits, data can be set to timeliness, similar to Memcache	Different application scenarios
Availability of	Support Master-slave,replicatset (internal use of Paxos election algorithm, automatic failback), auto sharding mechanism, blocking the failover and slicing mechanism to the client	Rely on the client to implement the distributed read and write, master-slave replication, every time from the node reconnect to the primary node to rely on the entire snapshot, no incremental replication; auto sharding is not supported, need to rely on the program to set the consistency hash mechanism	MongoDB is better than Redis; On a single point problem, MongoDB application is simple, relative user transparent, Redis is more complex, need the client to actively solve. (MongoDB is typically combined with replicasets and sharding, replicasets focus on high availability and high reliability, sharding focus on performance, horizontal scaling)
Reliability	Support for persistence in Binlog mode (MySQL-like) since version 1.8	Rely on snapshots for persistence; AOF enhances reliability and enhances performance while impacting access
Consistency	Transactions are not supported, guaranteed by the client	Support transactions, more brittle, only ensure that operations in the transaction are executed sequentially	Redis is better than MongoDB
Data analysis	Built-in data analysis capabilities (MapReduce)	Not supported	MongoDB is better than Redis
Application Scenarios	Increased access efficiency for massive data	Performance and operation of smaller data volumes	MongoDB is better than Redis

The comparison between MongoDB and Redis