The latest blog posts to take off on Hacker News. 4,390 posts.
In the previous Jepsen analysis of RethinkDB , we tested single-document reads, writes, and conditional writes, under network partitions and process pauses. RethinkDB did not exhibit any nonlinearizable histories in those tests. However, testing with more aggressive failure modes, on both 2.1.5 and 2.2.3, has…
This post talks about Ruby but it’s true of every language community: Python, JavaScript, Java, etc. The scourge of dependencies spares no one. This is a dependency visualization of every Rails app I’ve ever used. Does any of this sound familiar: Gemfile with 100s of entries. Test gems loading in production. Each…
Hamidreza Soleimani's Blog - Just about what I know
As part of the research for my book , I came across an algorithm called Redlock on the Redis website. The algorithm claims to implement fault-tolerant distributed locks (or rather, leases [1]) on top of Redis, and the page asks for feedback from people who are into distributed systems. The algorithm instinctively set…
Joe Duffy's Blog | Adventures in the high-tech underbelly
Recently I’ve been experimenting with freestanding C programs on Windows. Freestanding refers to programs that don’t link, either statically or dynamically, against a standard library (i.e. libc). This is typical for operating systems and similar, bare metal situations . Normally a C compiler can make assumptions…
Unikernel Profiling: Flame Graphs from dom0. This post investigates performance profiling of Unikernels, and with a proof of concept shows that with a little work a lot of observability is possible.
Updated February 2, 2016: Once you learn about our team and who we are, come take a trip down memory lane with us! Yesterday morning, the Hosted UI team, responsible for VMware’s Workstation …
Perf is probably the most widely used general purpose performance debugging tool on Linux. There are multiple contenders for the #2 spot, and, like perf, they're sampling profilers. Sampling profilers are great. They tend to be easy-to-use and low-overhead compared to most alternatives. However, there are large…
I was incredibly inspired by Tomasz Stachowiak’s hack of GCN . It made me wish I owned a GCN machine of my own to start trying insane things with. On the other hand, I dooo own an Intel Haswell GPU , and they dooo publish some really dense documentation that’s allegedly enough to write a complete driver with.
I’m hacking on an assembly project, and wanted to document some of the tricks I was using for figuring out what was going on. This post might seem a little basic for folks who spend all day heads down in gdb or who do this stuff professionally, but I just wanted to share a quick intro to some tools that others may…
For decades, the C and C++ standards treated multi-threading and concurrency as something existing outside the standard sphere - in that "target-dependent" world of shades which the "abstract machine" targeted by the standards doesn't cover. The immediate, cold-blooded replies of "C++ doesn't know what a thread is" in…
A flash of intuition while trying to find a way to lend brian d foy a hand in his search for excellent numbers helped me reduce run time by 95 percent.
I just finished updating my C compiler and minimal CPU specification to include virtual memory. The process of adding virtual memory support to a CPU, a kernel, and a compiler toolchain has made me realize that there is a lack of good explanations for how all of these parts fit together. I also realized that a…
I initially wrote this post for myself, I wanted to understand enough about the underlying physical storage to be able to grasp other concepts which can affect your database. This post is probably more aimed to people with similar interests, I will try to keep it accurate but the aim is to make it simpler to…
There's a network-server programming pattern which is so popular that it's the canonical approach towards writing network servers:
There are many great options for managing FreeBSD Jails. iocage, warden and ez-jail aim to streamline the process and make it quick an easy to get going. But sometimes the tools built right into the OS are overlooked.
Since Version 10.10 (Yosemite), OS X contains Hypervisor.framework, which provides a thin user mode abstraction of the Intel VT features. It enables apps to use virtualization without the need of a kernel extension (KEXT) – which makes them compatible with the OS X App Store guidelines.
Benchmarking throughput and latency of Amazon AWS Simple Storage Service (S3), Google Cloud Storage (GCS) and Microsoft Azure Storage object storage services
In this Jepsen report, we’ll verify RethinkDB’s support for linearizable operations using majority reads and writes, and explore assorted read and write anomalies when consistency levels are relaxed. This work was funded by RethinkDB, and conducted in accordance with the Jepsen ethics policy .
In 2007 I wrote about using PNGout to produce amazingly small PNG images. I still refer to this topic frequently, as seven years later, the average PNG I encounter on the Internet is very unlikely to be optimized. For example, consider this recent Perry Bible Fellowship cartoon. Saved directly from
QubesOS provides a desktop operating system made up of multiple virtual machines, running under Xen. To protect against buggy network drivers, the …
