Blast throughput is what we call a throughput measurement such that N requests are simultaneously sent to the server and the duration to receive responses for all N requests is recorded. The throughput is computed as N/duration where duration is in seconds. This is the typical and potentially correct way to measure throughput from a client to a server, however issues do arise in distributed systems land: the requests must all originate from a single client high latency response outliers can skew results you must be confident that N is big enough to max out the server N mustn’t be so big as to create non-server related bottlenecks....

In this post I’m just going to maintain a list of notes for Go testing that I seem to commonly need to reference. It will also serve as an index for the posts related to testing that I have to commonly look up as well. Here is a quick listing of the table of contents: Basics Table Driven Tests Fixtures Golden Files Frameworks No Framework Ginkgo & Gomega Helpers Temporary Directories Sources and References Basics Just a quick reminder of how to write tests, benchmarks, and examples....

In order to improve the performance of asynchronous message passing in Alia, I’m using gRPC bidirectional streaming to create the peer to peer connections. When the replica is initialized it creates a remote connection to each of its peers that lives in its own go routine; any other thread can send messages by passing them to that go routine through a channel, replies are then dispatched via another channel, directed to the thread via an actor dispatching model....

This is kind of a dumb post, but it’s something I’m sure I’ll look up in the future. I have a lot of emails where I have to send a date that’s sometime in the future, e.g. six weeks from the end of a class to specify a deadline … I’ve just been opening a Python terminal and importing datetime and timedelta but I figured this quick script on the command line would make my life a bit easier:...

Here’s the scenario: we have a buffered channel that’s being read by a single Go routine and is written to by multiple go routines. For simplicity, we’ll say that the channel accepts events and that the other routines generate events of specific types, A, B, and C. If there are more of one type of event generator (or some producers are faster than others) we may end up in the situation where there are a series of the same events on the buffered channel....

Building correct concurrent programs in a distributed system with multiple threads and processes can quickly become very complex to reason about. For performance, we want each thread in a single process to operate as independently as possible; however anytime the shared state of the system is modified synchronization is required. Primitives like mutexes can [ensure structs are thread-safe]({% post_url 2017-02-21-synchronizing-structs %}), however in Go, the strong preference for synchronization is communication....

Syntactic parsing is a technique by which segmented, tokenized, and part-of-speech tagged text is assigned a structure that reveals the relationships between tokens governed by syntax rules, e.g. by grammars. Consider the sentence: The factory employs 12.8 percent of Bradford County. A syntax parse produces a tree that might help us understand that the subject of the sentence is “the factory”, the predicate is “employs”, and the target is “12.8 percent”, which in turn is modified by “Bradford County”....