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Nvidia: Invalid or Corrupted Push Buffer Stream

By Neil Elliott
April 20, 2015

As a high-performance video rendering appliance, the Liquid Galaxy requires really good video cards—​better than your typical on-board integrated video cards. Despite ongoing attempts by competitors to displace them, Nvidia remains the best choice for high-end video, if you use the proprietary Nvidia driver for Linux.

In addition to providing regular security and system updates, End Point typically provides advanced remote monitoring of our customers’ systems for issues such as unanticipated application behavior, driver issues, and hardware errors. One particularly persistent issue presents as an error with an Nvidia kernel module.  Unfortunately, relying on proprietary Nvidia drivers so as to maintain an acceptable performance level limits the available diagnostic information and options for resolution.

The issue presents when the system ceases all video output functions as Xorg crashes. The kernel log contains the following error message:

2015-04-14T19:59:00.000083+00:00 lg2 kernel: [  719.850677] NVRM: Xid (0000:01:00): 32, Channel ID 00000003 intr 02000000

The message is repeated approximately 11000 times every second until the disk fills and the ability to log in to the …

Joe Mastey at Mountain West Ruby Conference 2015

By Brian Gadoury
April 17, 2015

A conversation with a co-worker today about the value of improving one’s professional skills reminded me of Joe Mastey’s talk he gave at the 2015 Mountain West Ruby Conference. That then reminded me that I had never finished my write up on that conference. Blogger won’t let me install harp music and an animated soft focus flashback overlay, so please just imagine it’s the day after the conference when you’re reading this. “That reminds me of the time…”

I’ve just finished my second MWRC and I have to give this one the same 5-star rating I gave last year’s. There were a few small sound glitches here and there, but overall the conference is well-run, inclusive, and packed with great speakers and interesting topics. Rather than summarizing each talk, I want to dig into the one most relevant to my interests. “Building a Culture of Learning” by Joe Mastey

I was excited to catch Joe’s talk because learning and teaching have always been very interesting to me, regardless of the particular discipline. I find it incredibly satisfying to improve upon my own learning skills, as well as improving my teaching skills by teasing out how different individuals learn best and then speak to …

RailsConf 2015: Coming Soon

By Steph Skardal
April 17, 2015

Next week, I’m headed to my 6th RailsConf in Atlanta, with the whole family in tow:

The gang. Note: Dogs will not be attending conference.

This will be a new experience since my husband will be juggling two kids while I attend the daily sessions. So it makes sense going into the conference fairly organized to aid in the kid juggling, right? So I’ve picked out a few sessions that I’m looking forward to attending. Here they are:

• Don’t be a Hero: Sustainable Open Source
• Riding Rails for 10 Years
• Scaling Rails For Black Friday and Cyber Monday
• Better Callbacks in Rails 5
• Microservices: A Bittersweet Symphony
• SVG Charts and Graphics with Ruby
• Building RailsPerf: A Toolkit to Detect Performance Regressions in Ruby on Rails Core
• High Performance APIs in Ruby Using ActiveRecord and Goliath
• What Comes After MVC
• Your Front End Framework is Overkill—​Server Side JavaScript with Rails
• Bringing UX To Your Code
• Coding: Art or Craft?
• What I’ve Learned in 7 Years of Podcasting About Ruby

RailsConf is a multi-track conference, with tracks including Distributed Systems, Culture, Growing Talent, Testing, APIs, Front End, Crafting Code, JavaScript, and Data & Analytics. There are also Beginner …

RubyConf India 2015

By Selvakumar Arumugam
April 15, 2015

The 6th edition of RubyConf India 2015 was held at Goa (in my opinion, one of the most amazing places in India). The talks were spread over various topics, mainly related to Ruby generally and RoR.

Aaron Patterson (a core member of Ruby and Rails team) gave a very interesting talk about Pair Programming, benchmarking on Integration tests vs Controller tests and precompiling the view to increase the speed in Rails 5.

Christophe Philemotte presented a wonderful topic on “Diving in the unknown depths of a project” with his experience of contributing to the Rails project. He mentioned that 85% of a developer’s time is spent on reading the code and 15% of the time is spent on writing the code. So he explained a work process plan to make use of the developer’s time effectively which should adopt well to any kind of development. Here is the list of steps he explained:

1. Goal (ex: bug fixing, implement new feature, etc… )
2. Map (ex: code repository, documentation, readme, etc…)
3. Equipment (ex: Editor, IDE) and Dive (read, write, run and use)
4. Next Task

Rajeev from ThoughtWorks talked about “Imperative vs Functional programming” and interesting concepts in Haskell which can be implemented in …

New NoSQL benchmark: Cassandra, MongoDB, HBase, Couchbase

By Jon Jensen
April 13, 2015

Today we are pleased to announce the results of a new NoSQL benchmark we did to compare scale-out performance of Apache Cassandra, MongoDB, Apache HBase, and Couchbase. This represents work done over 8 months by Josh Williams, and was commissioned by DataStax as an update to a similar 3-way NoSQL benchmark we did two years ago.

The database versions we used were Cassandra 2.1.0, Couchbase 3.0, MongoDB 3.0 (with the Wired Tiger storage engine), and HBase 0.98. We used YCSB (the Yahoo! Cloud Serving Benchmark) to generate the client traffic and measure throughput and latency as we scaled each database server cluster from 1 to 32 nodes. We ran a variety of benchmark tests that included load, insert heavy, read intensive, analytic, and other typical transactional workloads.

We avoided using small datasets that fit in RAM, and included single-node deployments only for the sake of comparison, since those scenarios do not exercise the scalability features expected from NoSQL databases. We performed the benchmark on Amazon Web Services (AWS) EC2 instances, with each test being performed three separate times on three different days to avoid unreproduceably anomalies. We used new EC2 …

Happy 10th birthday, Git!

By Jon Jensen
April 8, 2015

Git’s birthday was yesterday. It is now 10 years old! Happy birthday, Git!

Git was born on 7 April 2005, as its creator Linus Torvalds recounted in a 2007 mailing list post. At least if we consider the achievement of self-hosting to be “birth” for software like this. :)

Birthdays are really arbitrary moments in time, but they give us a reason to pause and reflect back. Why is Git a big deal?

Even if Git were still relatively obscure, for any serious software project to survive a decade and still be useful and maintained is an accomplishment. But Git is not just surviving.

Over the past 5–6 years, Git has become the standard version control system in the free software / open source world, and more recently, it is becoming the default version control system everywhere, including in the proprietary software world. It is amazing to consider how fast it has overtaken the older systems, and won out against competing newer systems too. It is not unreasonable these days to expect anyone who does software development, and especially anyone who claims to be familiar with version control systems, to be comfortable with Git.

So how did I get to be friends with Git, and end up at this birthday …

PgConf 2015 NYC Recap

By David Christensen
April 6, 2015

I recently just got back from PGConf 2015 NYC. It was an invigorating, fun experience, both attending and speaking at the conference.

What follows is a brief summary of some of the talks I saw, as well as some insights/thoughts:

On Thursday:

“Managing PostgreSQL with Puppet” by Chris Everest. This talk covered experiences by CoverMyMeds.com staff in deploying PostgreSQL instances and integrating with custom Puppet recipes.

“A TARDIS for your ORM—​application level timetravel in PostgreSQL” by Magnus Hagander. Demonstrated how to construct a mirror schema of an existing database and manage (via triggers) a view of how data existed at some specific point in time. This system utilized range types with exclusion constraints, views, and session variables to generate a similar-structured schema to be consumed by an existing ORM application.

“Building a ‘Database of Things’ with Foreign Data Wrappers” by Rick Otten. This was a live demonstration of building a custom foreign data wrapper to control such attributes as hue, brightness, and on/off state of Philips Hue bulbs. Very interesting live demo, nice audience response to the control systems. Used a python framework to stub out the …

Manage Python Script Options

By Szymon Lipiński
April 3, 2015

Some time ago I was working on a simple Python script. What the script did is not very important for this article. What is important, is the way it parsed arguments, and the way I managed to improve it.

All below examples look similar to that script, however I cut most of the code, and changed the sensitive information, which I cannot publish.

The main ideas for the options management are:

• The script reads all config values from a config file, which is a simple ini file.
• The script values can be overwritten by the command line values.
• There are special command line arguments, which don’t exist in the config file like:
  • –help — shows help in command line
  • –create-config — creates a new config file with default values
  • –config — the path to the config file which should be used
• If there is no value for a setting in the config file, and in the command line arguments, then a default value should be taken.
• The option names in the configuration file, and the command line, must be the same. If there is repo-branch in the ini file, then there must be –repo-branch in the command line. However the variable where it will be stored in Python will be named repo_branch, …