~?~

Aphyr About Blog Photos Code Needlepoint Writing Science Fiction 2019-01-02 Inspired by Peter Watts’ The Freeze-Frame Revolution and The Island . Each birth is violent in the same way. I erupt into the void, my mirrored surface riotous with gamma radiation, parafluid sheeting from my forced extremities, ripped away by gravitational shear beyond all comprehension. Terrible heat, terrible light: the exotic metals of my placenta flash-vaporize, ionize, and crackle around me, an expanding plasma aglow with the fire of the aperture’s parturition. Spacetime snaps flat, rebounds. The brilliance fades. Lightning heralds my arrival. No time to waste. I ripple, tweak my plasma frequencies just so . My surface furrows with interference patterns, from smooth waves to impossibly fine pinnacles, light dances in the depths of those nonlinear optical wells, and now I FU...

~?~

~?~

Login Password Aphyr Blog Photography Code About 2017/04/05 Writing Software JVM Interviews Previously: Reversing the technical interview . Long ago, on Svalbard, when you were a young witch of forty-three, your mother took your unscarred wrists in her hands, and spoke: Vidrun, born of the sea-wind through the spruce Vidrun, green-tinged offshoot of my bough, joy and burden of my life Vidrun, fierce and clever, may our clan’s wisdom be yours: Never read Hacker News But Hacker News has read of you, in their snicker-slithing sussurential warrens, and word has spread, which is why the young man offering you a smörgåsbord of microkitchen offerings looks mildly suspicious already. He whisks you into a glass shoebox of a conference room, which somehow manages to be claustrophobic despite the open sightlines. You make a mental note to avoid this conference ...

Login Password Aphyr Blog Photography Code About 2017/04/05 Writing Software JVM Interviews Previously: Reversing the technical interview . Long ago, on Svalbard, when you were a young witch of forty-three, your mother took your unscarred wrists in her hands, and spoke: Vidrun, born of the sea-wind through the spruce Vidrun, green-tinged offshoot of my bough, joy and burden of my life Vidrun, fierce and clever, may our clan’s wisdom be yours: Never read Hacker News But Hacker News has read of you, in their snicker-slithing sussurential warrens, and word has spread, which is why the young man offering you a smörgåsbord of microkitchen offerings looks mildly suspicious already. He whisks you into a glass shoebox of a conference room, which somehow manages to be claustrophobic despite the open sightlines. You make a mental note to avoid this conference ...

Login Password Aphyr Blog Photography Code 2013/10/26 Software Clojure Clojure from the ground up This guide aims to introduce newcomers and experienced programmers alike to the beauty of functional programming, starting with the simplest building blocks of software. You’ll need a computer, basic proficiency in the command line, a text editor, and an internet connection. By the end of this series, you’ll have a thorough command of the Clojure programming language. Science, technology, engineering, and mathematics are deeply rewarding fields, yet few women enter STEM as a career path. Still more are discouraged by a culture which repeatedly asserts that women lack the analytic aptitude for writing software, that they are not driven enough to be successful scientists, that it’s not cool to pursue a passion for structural engineering. Those few with the tale...

Login Password Aphyr Blog Photography Code 2015/02/12 Ruby Software Clojure So there’s a a blog post that advises every method should, when possible, return self . I’d like to suggest you do the opposite: wherever possible, return something other than self . Mutation makes code harder to reason about. Mutable objects make equality comparisons tricky: if you use a mutable object as the key in a hashmap, for instance, then change one of its fields, what happens? Can you access the value by the new string value? By the old one? What about a set? An array? For a fun time, try these in various languages. Try it with mutable primitives, like Strings, if the language makes a distinction. Enjoy the results. If you call a function with a mutable object as an argument, you have very few guarantees about the new object’s value. It’s up to you to enforce invariants ...

~?~

Login Password Aphyr Blog Photography Code 2014/06/15 Distributed Systems Jepsen Elasticsearch Previously, on Jepsen , we saw RabbitMQ throw away a staggering volume of data. In this post, we’ll explore Elasticsearch’s behavior under various types of network failure. Elasticsearch is a distributed search engine , built around Apache Lucene–a well-respected Java indexing library. Lucene handles the on-disk storage, indexing, and searching of documents, while ElasticSearch handles document updates, the API, and distribution. Documents are written to collections as free-form JSON; schemas can be overlaid onto collections to specify particular indexing strategies. As with many distributed systems, Elasticsearch scales in two axes: sharding and replication . The document space is sharded–sliced up–into many disjoint chunks, and each chunk allocated to differe...

Login Password Aphyr Blog Photography Code 2014/06/09 Distributed Systems Jepsen Networks Etcd Consul In the previous post, we discovered the potential for data loss in RabbitMQ clusters . In this oft-requested installation of the Jepsen series, we’ll look at etcd : a new contender in the CP coordination service arena. We’ll also discuss Consul ’s findings with Jepsen. Like Zookeeper, etcd is designed to store small amounts of strongly-consistent state for coordination between services. It exposes a tree of logical nodes; each identified by a string key, containing a string value, and with a version number termed an index –plus, potentially, a set of child nodes. Everything’s exposed as JSON over an HTTP API. Etcd is often used for service discovery, distributed locking, atomic broadcast, sequence numbers, and pointers to data in eventually consistent sto...

Login Password Aphyr Blog Photography Code Call me maybe: RabbitMQ RabbitMQ is a distributed message queue, and is probably the most popular open-source implementation of the AMQP messaging protocol. It supports a wealth of durability, routing, and fanout strategies, and combines excellent documentation with well-designed protocol extensions. I’d like to set all these wonderful properties aside for a few minutes, however, to talk about using your queue as a lock service. While I was working on building Knossos –Jepsen’s linearizability checker –a RabbitMQ blog post made the rounds of various news aggregators. In this post, the RabbitMQ team showed how one could turn RabbitMQ into a distributed mutex or semaphore service. I thought this was a little bit suspicious, because the RabbitMQ documentation is very clear that partitions invalidate essentially all Rab...