- In many cases we want messaging across systems to be reliable (delivery guranteed), but the major communication protocols like http/tcp are unreliable
- To support reliable messaging and guaranteed delivery, middleware called as Message Queue is used
- Refer Here for wiki definitions of Message Queues
- Popular Message Queues Refer Here
- Active MQ
- Rabbit MQ
- Apache Kafka
- All the data about the systems are stored in Databases.
- Generally databases store the information on Disk in their own formats.
- Whenever application sends request to pull the information, Disk I/O has to happen and disks are generally slow in nature.
- RAM is faster than Disk, so if we can store the data which is changed infrequently on RAM then queries must be faster.
- So we introduce a Server which loads all the infrequently changed/static data into the RAM and when any application queries this data it can give quick response and thats the whole idea of Cache Servers
- Poplular Cache Servers Refer Here
- Elastic Cache