A Java Geek weekly 80

A couple of years ago, Reactive Programming was all the rage, but it had one big issue: reactive stopped as soon as you accessed a SQL database. You had a nice reactive chain up to the database, defeating the whole purpose. Given the prevalence of SQL databases in existing and new apps, one couldn’t enjoy the full benefits of Reactive Programming but still pay the full price of complexity.

Since then, the landscape has changed tremendously. Most importantly, it offers many reactive drivers over popular databases: PostgreSQL, MariaDB and MySQL, Microsoft SQL Server, Oracle, you name it! Even better, some frameworks provide a reactive API over them.

Even though I’m not providing consulting services regularly, I wanted to keep up-to-date on accessing data reactively. In this post, I’ll describe Hibernate Reactive, Spring Data R2DBC, and jOOQ in no particular order.

For building a system of distributed services, one concept I think is very valuable to keep in mind is what I call the synchrony budget: as much as possible, a service should minimize the number of synchronous requests which it makes to other services.

WebAssembly components offer a new way to deploy microservices and other applications in cloud native environments. This naturally raises the question: is the upstart component out to replace containers? Or is this one of those situations where the apparent rivals need to learn to work together?

For a proper answer, we need to examine the similarities and differences between the two technologies, and then consider how we should understand their respective use-cases—both taken independently or working in tandem.

Then we’ll explore how WebAssembly (Wasm) can extend the frontiers of container orchestration across multiple clouds, edges, and devices.

Template strings are a generalization of f-strings, using a t in place of the f prefix. Instead of evaluating to str, t-strings evaluate to a new type, Template:

template: Template = t"Hello {name}"

Templates provide developers with access to the string and its interpolated values before they are combined. This brings native flexible string processing to the Python language and enables safety checks, web templating, domain-specific languages, and more.