Facebook Scala
Scala is a general-purpose programming language that is designed to be concise, expressive, and scalable. Developed by Martin Odersky and his team at EPFL, Scala combines object-oriented and functional programming concepts, making it an attractive choice for developers who want to write clean and efficient code. One prominent user of Scala is Facebook, which has adopted Scala for a variety of projects.
Why Scala?
Scala offers several advantages over other programming languages, making it a natural fit for complex systems like those at Facebook.
1. Expressive Syntax
Scala's expressive syntax allows developers to write code that is more concise and readable. It supports a wide range of programming paradigms, including functional programming, object-oriented programming, and concurrent programming. This flexibility enables developers to choose the style that best fits their needs.
2. Static Typing
Scala is statically typed, which means that the compiler can catch many errors at compile-time, rather than at runtime. This leads to more robust and reliable code, as type errors can be detected early in the development process. However, Scala also provides type inference, which allows developers to omit type annotations in many cases and write code that is more concise.
3. Scalability
Scala is designed to scale, both in terms of performance and codebase size. It can seamlessly integrate with existing Java code, allowing developers to leverage the vast ecosystem of Java libraries and frameworks. Additionally, Scala's support for functional programming and immutability makes it easier to write code that can be parallelized and distributed across multiple machines.
4. Tooling and Community
Scala has a vibrant and active community, with numerous open-source libraries and frameworks available for developers to use. It also has excellent tooling support, including powerful IDEs like IntelliJ IDEA and build tools like sbt. Facebook, being a prominent user of Scala, has contributed to the development of these tools and libraries, making them even more robust and feature-rich.
Examples of Scala at Facebook
Facebook has adopted Scala for various projects, ranging from backend services to data analysis. One of the notable projects is Scuba, a distributed, in-memory time-series database. Scuba is used internally at Facebook for real-time monitoring and analysis of large-scale data. Here is an example of how Scala code looks like in Scuba:
import com.facebook.scuba.{Scuba, ScubaOptions}
val options = new ScubaOptions()
options.setBlockSize(4096)
val scuba = new Scuba(options)
scuba.start()
val data = scuba.query("SELECT * FROM my_table WHERE timestamp > 1600000000")
data.foreach { row =>
val timestamp = row.getLong("timestamp")
val value = row.getDouble("value")
println(s"Timestamp: $timestamp, Value: $value")
}
scuba.stop()
In this example, we create a ScubaOptions object to configure the Scuba database. We then create a Scuba instance and start it. We execute a SQL-like query to retrieve data from a table and iterate over the results to print the timestamp and value of each row. Finally, we stop the Scuba instance.
Another example of Scala usage at Facebook is the Presto query engine. Presto is a distributed SQL query engine that is designed for fast and interactive query execution on large datasets. Scala is used extensively in Presto's codebase, allowing developers to write high-performance and maintainable code. Here is a simplified example of a Presto query in Scala:
import com.facebook.presto.{Presto, PrestoOptions}
val options = new PrestoOptions()
options.setQuery("SELECT * FROM my_table WHERE timestamp > 1600000000")
val presto = new Presto(options)
presto.execute()
val results = presto.getResults()
results.foreach { row =>
val timestamp = row.getLong("timestamp")
val value = row.getDouble("value")
println(s"Timestamp: $timestamp, Value: $value")
}
In this example, we create a PrestoOptions object to configure the Presto query engine. We set the SQL query to retrieve data from a table and execute it. We then iterate over the results and print the timestamp and value of each row.
Conclusion
Scala is a powerful and versatile programming language that has gained popularity in the industry, with Facebook being one of its prominent users. Its expressive syntax, static typing, scalability, and excellent tooling support make it an ideal choice for developing complex systems like those at Facebook. With Scala, developers can write clean, efficient, and maintainable code, enabling them to build robust and scalable applications.
