Our great sponsors
-
tidb
TiDB is an open-source, cloud-native, distributed, MySQL-Compatible database for elastic scale and real-time analytics. Try AI-powered Chat2Query free at : https://tidbcloud.com/free-trial
-
InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
I do agree with you in that regard, however, that's also a dangerous line of thinking.
There are attempts to provide horizontal scalability for RDBMSes in a transparent way, like TiDB https://pingcap.com/ (which is compatible with the MySQL 5.7 drivers), however, the list of functionality that's sacrificed to achieve easily extensible clusters is a long one: https://docs.pingcap.com/tidb/stable/mysql-compatibility
There are other technologies, like MongoDB, which sometimes are more successful at a clustered configuration, however most of the traditional RDBMSes work best in a leader-follower type of replication scenario, because even those aforementioned systems oftentimes have data consistency issues that may eventually pop up.
Essentially, my argument is that the lack of good horizontally scalable databases or other data storage solutions is easily explainable by the fact that the problem itself isn't solvable in any easy way, apart from adopting eventual consistency, which is probably going to create more problems than it will solve in case of any pre-existing code that makes assumptions about what ways it'll be able to access data and operate on it: https://en.wikipedia.org/wiki/Fallacies_of_distributed_compu...
To that end, i'd perhaps like to suggest an alternative: use a single vertically scalable RDBMS instance when possible, with a hot standby if you have the resources for that. Let the architecture around it be horizontally scalable instead, and let it deal with the complexities of balancing the load and dealing with backpressure - introduce a message queue if you must, maybe even an in-memory one for simplicity's sake, or consider an event based architecture where "what needs to be done" is encapsulated within a data structure that can be passed around and applied whenever possible. In my eyes, such solutions can in many cases be better than losing the many benefits of having a single source of truth.
Alternatively, consider sharding as a possibility, or, alternatively, do some domain driven design, figure out where to draw some boundaries and split your service into multiple ones that cover the domain with which you need to work with. Then you have one DB for sales, one for account management, one for reports and so on, all separated by something as simple as REST interfaces and with rate limits or any of the other mechanisms.
If, however, neither of those two groups of approaches don't seem to be suitable for the loads that you're dealing with, then you probably have a team of very smart people and a large amount of resources to figure out what will work best.
To sum up, if there are no good solutions in the space, perhaps that's because the problems themselves haven't been solved yet. Thus, sooner or later, they'll need to be sidestepped and their impact mitigated in whatever capacity is possible.