tag
Microservices
- #68 12 min
Thrift on Steroids: A Tale of Scale and Abstraction
Apache Thrift is an RPC framework developed at Facebook for building “scalable cross-language services.” It consists of an interface definition language (IDL), communication protocol, API libraries, and a code generator that allows you to build and evolve services independently and in a polyglot fashion across a wide range of languages. This is nothing new and has been around for over a decade now. There are a number of notable users of Thrift aside from Facebook, including Twitter (mainly by way of Finagle), Foursquare, Pinterest, Uber (via TChannel), and Evernote, among others—and for good reason, Thrift is mature and battle-tested.
- #63 6 min
Smart Endpoints, Dumb Pipes
I read an interesting article recently called How do you cut a monolith in half? There are a lot of thoughts in the article that resonate with me and some that I disagree with, prompting this response. The overall message of the article is don’t use a message broker to break apart a monolith because it’s like a cross between a load balancer and a database, with the disadvantages of both and the advantages of neither. The author argues that message brokers are a popular way to pull apart components over a network because they have low setup cost and provide easy service discovery, but they come at a high operational cost. My response to that is the same advice the author puts forward: it depends.
- #57 6 min
Take It to the Limit: Considerations for Building Reliable Systems
Complex systems usually operate in failure mode. This is because a complex system typically consists of many discrete pieces, each of which can fail in isolation (or in concert). In a microservice architecture where a given function potentially comprises several independent service calls, high availability hinges on the ability to be partially available. This is a core tenet behind resilience engineering. If a function depends on three services, each with a reliability of 90%, 95%, and 99%, respectively, partial availability could be the difference between 99.995% reliability and 84% reliability (assuming failures are independent). Resilience engineering means designing with failure as the normal.
- #43 3 min
Designed to Fail
When it comes to reliability engineering, people often talk about things like fault injection, monitoring, and operations runbooks. These are all critical pieces for building systems which can withstand failure, but what’s less talked about is the need to design systems which deliberately fail. Reliability design has a natural progression which closely follows that of architectural design. With monolithic systems, we care more about preventing failure from occurring. With service-oriented architectures, controlling failure becomes less manageable, so instead we learn to anticipate it. With highly distributed microservice architectures where failure is all but guaranteed, we embrace it.
- #42 5 min
Service-Disoriented Architecture
“You can have a second computer once you’ve shown you know how to use the first one.” -Paul Barham The first rule of distributed systems is don’t distribute your system until you have an observable reason to. Teams break this rule on the regular. People have been talking about service-oriented architecture for a long time, but only recently have microservices been receiving the hype. The problem, as Martin Fowler observes, is that teams are becoming too eager to adopt a microservice architecture without first understanding the inherent overheads. A contributing factor, I think, is you only hear the success stories from companies who did it right, like Netflix. However, what folks often fail to realize is that these companies—in almost all cases—didn’t start out that way. There was a long and winding path which led them to where they are today. The inverse of this, which some refer to as microservice envy, is causing teams to rush into microservice hell. I call this service-disoriented architecture (or sometimes disservice-oriented architecture when the architecture is DOA).