The fsync policy equivalent to SQL database would be "fsync on each change before reporting successful update to the app". Redis (as many NoSQL databases) also doesn't have SQL and is a pain to view the data, you need to write extra tools when investigating the problems.
RDB snapshots can cause multiple page faults due to use of fork() and CoW.
> It's easier to scale
The company in question manages online stores and they could easily scale by allocating a separate database for each store (sharding).
> But I think using Redis is much more elegant.
I cannot agree because I think using a single database for all the data is more elegant, than multiple different databases and there are less problems to deal with. I dislike microservice-style architecture strongly and believe it is mostly good for wasting company's money.
> 'Use only MySQL as a solution to the distributed transaction consistency problem between two different storage systems, Redis and MySQL!'
I read it as "do not create unnecessary work by using a single database".
It's interesting that our views differ. I think it's because of our different experiences. I believe MSA is the right approach. But this doesn't seem like a debate that can be resolved through discussion. It's something that needs to be implemented and tested.
Still, I respect your perspective and your experience. We clearly have different values, but I think you have a mature engineering mindset. Ultimately, I think only real measurements can settle this. Have a great day.
RDB snapshots can cause multiple page faults due to use of fork() and CoW.
> It's easier to scale
The company in question manages online stores and they could easily scale by allocating a separate database for each store (sharding).
> But I think using Redis is much more elegant.
I cannot agree because I think using a single database for all the data is more elegant, than multiple different databases and there are less problems to deal with. I dislike microservice-style architecture strongly and believe it is mostly good for wasting company's money.
> 'Use only MySQL as a solution to the distributed transaction consistency problem between two different storage systems, Redis and MySQL!'
I read it as "do not create unnecessary work by using a single database".