eventual-consistency

For example amazon.com; they rely on microservice architecture and probably order and payment are seperate micro services but when you checkout order on amazon.com you can finally see the order id and details.If it's not eventual consistency approach what is it? Maybe 2PC? I'm generalizing my question; what if eventual consistency is not appropriate for business transaction(end user should see the result end of transaction) but seperate microservices is meaningful(like order and payment) how to handle immediate consistency? There are several techniques which can provide cross-service

In a microservice architecture, we usually have two ways to communicate 2 microservices. Let’s say service A needs to get information from service B. The first option is an remote call, usually synchronous over HTTPS, so service A query an API hosted by service B. The second option is adopting an event-driven architecture, where the state of service B can be published and consumed by service A in asynchronous way. Using this model, the service A can update its own database with the information from the service B’s events and all queries are made locally in this database. This approach has the

Are there any algorithms that are commonly used for achieving eventual consistency in distributed systems? There are algorithms that have been developed for ACID transactions in distributed systems, Paxos in particular, but is there a similar body of theory that has been developed for BASE scenarios, with weaker consistency guarantees? Edit: This appears to be an area of academic research that is only beginning to be developed. Mcdowella's answer shows that there has been at least some work in this area. If "Anti-entropy protocols for repairing replicated data, which operate by comparing

What is the meaning of eventual consistency in Cassandra when nodes in a single cluster do not contain the copies of same data but data is distributed among nodes. Now since a single peice of data is recorded at a single place (node). Why wouldn't Cassandra return the recent value from that single place of record? How do multiple copies arise in this situation? Its up to the client to decide the appropriate consistency level (zero, any, one, quoram or all). (The consistency level controls both read and write behavior based on your replicationfactor.) In a single node cluster the consistency

Elasticsearch doesn't have "read consistency" param (like Cassandra). But it has " write consistency " and " read preference ". Documentation says the following about Write Consistency Write Consistency To prevent writes from taking place on the "wrong" side of a network partition, by default, index operations only succeed if a quorum (>replicas/2+1) of active shards are available. This default can be overridden on a node-by-node basis using the action.write_consistency setting. To alter this behavior per-operation, the consistency request parameter can be used. Valid write consistency values

I often hear about eventual consistency in different speeches about NoSQL, data grids etc. It seems that definition of eventual consistency varies in many sources (and maybe even depends on a concrete data storage). Can anyone give a simple explanation what Eventual Consistency is in general terms, not related to any concrete data storage? Eventual consistency: I watch the weather report and learn that it's going to rain tomorrow. I tell you that it's going to rain tomorrow. Your neighbor tells his wife that it's going to be sunny tomorrow. You tell your neighbor that it is going to rain

When using distributed and scalable architecture, eventual consistency is often a requirement. Graphically, how to deal with this eventual consistency? Users are used to click save, and see the result instantaneously... with eventual consistency it's not possible. How to deal with the GUI for such scenarios? Please note the question applies both for desktop applications and web applications. PS: I'm working with the Microsoft platform, but I imagine the question applies to any technology... A Task Based UI fits this model great. You create and execute tasks from the UI. You can also have