Tag Archives | lug

Notes from NH Ruby/Rails, 21-Feb-2011

Eight attendees made it to the February meeting of the New Hampshire Ruby Rails group at the New Hampshire Innovation Commercialization Center. A round of introductions included the usual suspects and several new people with interesting backgrounds and interests.

Brian Turnbull talked about Ruby debugging. He had a sample he created on Github Ruby comes with it’s own debugging library, but you can add a good one with a gem: ruby-debug.
Commands:
list – lists the code currently load
next – steps through the code listed, but skips over subroutines.
step – steps into the code
where – dumps the stack
finish – finishes the current subroutine call
display – dumps a value
(commonly use display value.inspect to make a cleaner display)
pp – pretty print, evaluates any Ruby code you want
edit – launches the EDITOR variable in our shell
catch – catch exceptions
cont – continue
break – set a breakpoint

,,, and so forth. Use the help, it is your friend.

The second example is far more complex, with a Sinatra app using OmniAuth and an LDAP provider. Following the supplied documentation, the app crashes on startup. (That’s what you get for reading the docs!) Debug and another tool – rbtrace to the rescue! Excellent demo of the problem and how the tools can debug them.

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Notes from CentraLUG, 6-Dec-2010: David Berube, MySQL Operations

Six people attended the December 2010 meeting of the Central New Hampshire Linux Group, held at the NHTI‘s Library from 7 to 9 PM. David Berube was the featured speaker, talking about his experience with large scale high-performance MySQL applications.

David is an independent software developer and consultant. One of his larger projects over the past couple of years has been an application for scheduling actors for auditions. This involves agents and projects, auditions, roles, videos and a number of other entities in a complex and fast-moving application. He’s used Ruby on Rails, PHP, MySQL, a NOSQL database, Amazon S3, A rack of Mac Minis, BSD, Linux, and a number of other elements. He had some insightful things to say about the development process, managing a client project, handling difficult requirements, scaling up million-row databases for subsecond response times and more. It was a meeting well worth attending.

There were a lot of useful tools and reference sites mentioned, and I was only able to take note of a few: Useful Ruby add-ons: New Relic, Query Reviewer, Percona Operations Day, Cacti for data aggregation. An In-depth discussion of NoSQL (“Not Only SQL”) Databases: what are they, what are they good for, what are the liabilities? A good discussion of the trade-offs of using NoSQL, reference to the NHRuby presentation on Redis a few months ago, and more.

Thanks to David for an informative presentation, to the attendees for a dynamic interactive session, and to the NHTI Library for the facilities. Future meetings at the Concord location have been suspended, we encourage our regulars to attend the Manchester ManchLUG meetings. If you haven’t already, consider subscribing to the announcement list so you’ll know when there’s an upcoming meeting. (Subscribers to the discussion list will automatically receive the announcements, too.)

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Notes from Ruby SIG, 16-Aug-2010

The New Hampshire Ruby/Rails group met as usual on the 3rd Monday of the month. We met at the New Hampshire Innovation Commercialization Center, a new space near the Pease airfield. Mark Galvin, NHICC’s Managing Director, was kind enough to offer the space for our meeting and tell us about the ICC. Eleven members attended the meeting.

As we often do, we started with a round of introductions. It’s always interesting to find out who’s there and what they’re up to. I mentioned the GNHLUG calendar and Nick plugged the upcoming Rails Rumble. Near the end of the meeting, we plugged the NorthEast RailsCamp, coming up on it’s third meeting, this one in Stowe, VT. 5 alums from previous camps were there, and all loved it. There may still be a ticket or two left, even though the site says zero – you’d better hurry!

We were lucky enough to have two presentations tonight.

Brian Turnbull presented “Interfacing Ruby with C.” He explained he needed to do some automation with a “black box” his company was using, and their documentation consisted of a C API and a DLL. Rather than developing an entire application in C, he used Ruby to interface to the C API and then could develop an easy-to-modify Ruby app. That turned out to be a good idea, as the final product he delivered turned out to be very different from the initial request, and having the ability to rapidly re-develop in Ruby was a success. To show us how to use C to access Ruby and vice-versa, Brian used a simple example of a “leaky bucket stack,” a fixed-length stack that would lose the oldest item as the stack was pushed. It was a great example in that it had enough complex behavior to be useful, while simple enough to explain and translate into C without too much effort. First, we reviewed the pure Ruby implementation. Brian proceeded to build up the equivalent code in C, calling Ruby array functionality and data types where appropriate. He then showed how to configure the C extension from from Ruby, build, compile, debug and run from the ruby command line.

See the example code and slides (I’ll update the URL when available). Also http://github.com/bturnbull/padpaws for his more advanced C example.

Brian Cardarella, @bcardarella, http://bcardarella.com, presented his gem, client-side validation, which he developed while working on the “Raise Your Vote” site for the Democratic National Committee. The Raise Your Vote site is intended to assist in voter registration by collecting data online and generating matching PDFs of the voter application. Naturally, 50 states have fifty different forms, with different requirements. He wanted to avoid duplicating the server-side validations with hand-maintained client side code, as the regular changing of requirements and the difficulty of keeping business rules in synch across the two languages would doom the project. He wrote client-cisde_validations to use the declarative validations within the entity models to generate the equivalent Javascript code. Client-side_validations has remarkable depth and breadth, handling nearly all of the common and exceptional types of valiation (Brian notes the few difficult cases in his slides). You can find the code on GitHub (gem code, examples) and the slides here: client_side_validations.pdf

Thanks to Brian Cardarella for travelling all the way to Portsmouth and thanks to both Brians for their fine presentations. Thanks to Nick Plante and Brian Turnbull for organizing and promoting the meeting and the group. And thanks to Mark Galvin and the New Hampshire Innovation Commercialization Center for providing the fine facilities!

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CentraLUG, 6 July 2009: Philip Sbrogna, WINE

WINE may or may not stand for “WINE Is Not an Emulator;” you might consider coming to the meeting to find out.

The July meeting of the Central New Hampshire Linux User Group, CentraLUG, will happen on the usual first Monday of the month, starting at 7 PM at the Hopkinton Public Library’s Community Room. Gather for Q&A and informal chat at 6:30.

Philip Sbrogna, an activist with the Monadnock Linux User Group, MonadLUG, will be presenting WINE. Philip got his start in the field of computers programming games for early microcomputers in ’79 after which he spent some time on mini’s at DEC. After an intermission on submarines he returned to the world of corporate computing where his daily fare at a small southern NH company provides him some opportunity to do the DB & Web dev thing. Personal interests include optimizing algorithms & innovative datastructures; particularly NXDs. He’s been a Linux enthusiast since switching from Coherent to Slackware in ’94.

Learn more about running Windows programs under Linux natively (Ubuntu Jaunty for presentation). Talk will include architectural overview & practical demonstration of what works and what doesn’t. Bring your favorite Window program along to see how it fares.

Note this meeting is at the Hopkinton Public Library 61 Houston Drive, Hopkinton/Contoocook, NH. Google map here. (Also, if you are coming from the southwest on route 202/9, the route 127 road over the Hopkinton Dam is once again open after a long repair closure.)

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Notes from MonadLUG, 14-May-2009, Tim Wessels and Kablink

Five people attended the May meeting of the Monadnock Linux User Group. Thanks to Charlie for scrambling at the last minute to secure the Peterborough Town Library for the meeting, as our regular venue was unavailable. Charlie made the iniital announcements – Ed Lawson presents Scribus in June, Charlie will show OpenBSD in July, no August meeting, and Patrick Galbraith returns for another (not-to-be-missed) meeting on MySQL in September.

Tim Wessels did the main presentation of the evening. Kablink is the Open Source version of Novell’s Teaming product, bought from SiteScape, Inc., a company that started in Clock Tower Place in Maynard, MA. The Open Source version had been known as ICECore previously. Source code can be downloaded from http://www.kablink.org and sourceforge. Tim discussed some of the history of the project, where and how it is being used, possible ways to configure it for workgroup and corporate enterprise use. and reviewed some of the challenges and tricks to installation and configuration. If you’re looking for an Open Source competitor to Microsoft’s Sharepoint, with the ability to create portals, finely-control roles and access, and scale to thousands of documents, Kablink is worth investigating.

Thanks to Tim for the presentation, Charlie for running the meeting, and all for attending!

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CentraLUG, 2-June-2008, Hopkinton, NH: Open Source Advocacy

The monthly meeting of CentraLUG, the Concord/Central NH GNHLUG chapter, happens the first Monday of most months. On June 2nd, we’ll be meeting at the Hopkinton Public Library from 7 PM to 9 PM. (Directions and maps here. [Edit: updated to current link 2014, too late for you to make the meeting, sorry.]) Open to the public. Free admission. Tell your friends. At this meeting, Mark Boyajian, Bill Sconce and other special guests will discuss “Open Source Advocacy.” I hope this spurs some discussions on how we can duplicate their success and avoid problems they can experienced.

About the presentation: Mark and Bill have been working with the Pepperell (MA) Lawrence Library to raise awareness of Open Source software solutions. They kicked-off this effort with a presentation last October in support of Software Freedom Day. The enthusiasm of library director Debra Spratt resulted in the Lawrence Library Tech Talk series: a monthly presentation on Open Source software and issues. Additionally, Debra has facilitated the creation of an Open Source information kiosk as well as a Linux-based computer in the reference library for use by the public!

The Tech Talk series formally launched in February and has consistently drawn a good audience. The kiosk and computer have been up and accessible since March. The experiences of working with this rich environment has surprised, challenged, and taught us many things we never expected. We are all working and adapting to better understand the [technical] needs and interests of the community and how the library can support them.

About Mark and Bill: Mark is an IT consultant (Simple Solutions) specializing in curriculum development and training, database development, and information management using Open Source solutions wherever possible. Mark “started life” as a music teacher, spent 20 years as an environmental field scientist specializing in wetlands and data management, and launched Simple Solutions as a full-time endeavor in 2001 built on Open Source solutions.

Bill Sconce is the proprietor of In-Spec, Inc., a Milford, NH-based consulting company. Bill is an activist with the Greater New Hampshire Linux Group, Secretary to the Board of Directors and coordinator of the Python Special Interest Group. He’s presented to most of the chapters and advocates for Open Source software at many other venues, including the McAuliffe and the NELS/FOSSEd conferences.

Future Meetings: Stay tuned for details on the upcoming bbq/picnic all-hands meeting in July, and for the location of the August meeting, still TBD. As always, meetings are subject to change. You are encouraged to join the low-traffic announcement list at http://mail.gnhlug.org/mailman/listinfo/gnhlug-announce to get announcement and cancellation information.

Meeting promotions: I’ve posted this meeting at lots of locations: FindEventsFast, Eventful, zVents, Upcoming, the GNHLUG announcement list, NHPR, the Concord Monitor. I’d be interested in hearing about where you learned of the event to better tune the meeting promotions.

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Notes from CentraLUG, 5-May-2008, Ben Scott, The Linux Server That Could

Nineteen people made May 5th’s CentraLUG meeting the second best attended of any LUG meeting so far this year, and the most populous CentraLUG meeting in over two years!

The meeting starting with a rag-tag band of Linux enthusiasts wandering around the campus looking for a room to meet. It’s finals week at NHTI and we’d been bumped from our regular spot. From the Library to the Crocker building to the Little Building we moved as more and more and more attendees arrived and we outgrew our first and second choices of rooms. Thanks to all for patience and multiple moves, and apologies for any folks we lost along the way.

The hassle was worthwhile, as Ben put on a great presentation on “The Linux Server That Could: Setting up a Small Office Server.” Over the years, both as part of his work and his hobbies, Ben has set up many multi-purpose computer servers: a single machine to serve a small workgroup with mail, files, printing, centralized DNS, DHCP. Ben had some slides to introduce the concepts and frame the problems his scripts solves, and then he dove into how to set up and configure the services. Providing a running commentary while he showed us configuration files, he offered a number of Best Practices tips for configuring, naming your intranet ‘domain,’ how CentOS/Red Hat family distros work, the differences in different flavors of Linux distros, editing configuration files, viewing error logs and more. It was a content-filled hour!

Slides and sample scripts and configuration files can be found on the GNHLUG web site here. Thanks to Ben for a great presentation, to Bruce Dawson for last-minute projector duty, to Bill Sconce for helping with the raffle, to the NHTI staff for helping us find facilities, and to all who attended and participated!

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MerriLUG Notes, 20-March-2008

Nine people make it to Thursday’s MerriLUG meeting, held on the very last night of astronomical winter, in this case the third Thursday of March, at Martha’s Exchange in Nashua. As was announced, the meeting was unstructured, informal, social and general conversations. A good time was had by all.

Matt mentioned that he’d recently received the designation of Red Hat Certified Architect, currently the top-tier of RH certification, requiring quite a bit of studying and passing some difficult exams. Congratulations, Matt!

Heather talked about some of the issues with calendaring using Evolution and Mozilla Thunderbird/Lightning, and that lead to a general conversation on the disaster that mankind has made of time zones, daylight savings time, expensive telephone systems that can’t cope, countries that change their minds, and so forth.

Ben was heckled in person, as he showed up. He brought a recent Dell lightweight laptop which he obligingly took apart for us to examine the various peripherals. An attempt at installing 2 Gb of Live Ubuntu onto a 1 Gb memory stick was unsurprisingly unsuccessful. He’s also been trying to get a USB wireless widget to work with Ubuntu. Matt plugged it in and showed it would work with Fedora 8, but then Matt’s an RHCA :).

This lead to a discussion of Network Manager, its strengths and
weaknesses, new features coming soon.

Conversation roamed all over the placing, including:

  • Proper grounding of data center racks.
  • Sprinkler systems.
  • EPO (Emergency Power Off) switches.
  • 50 Hz equipment is not a bargain in 60 Hz countries.
  • Proper lacing of cables.
  • MythTV, HDHomeRuns, TiV0, podcasts
  • the upcoming spam conference at MIT

One fellow, whose name I did not catch (he mentioned he was not good with names; me, neither!) brought along an OLPC and we talked about its engineering genius quite a bit. We didn’t talk much about its retail disaster, thankfully. Beautiful machines!

Kenta and Kevin and Mike also attended and contributed and participated.

Thanks to all for coming and participating, to Jim for arranging and announcing the meeting, to Heather for running the group and to Martha’s for providing the food and beer and facilities. Next month, we hope to have a very exciting meeting, but it’s not yet ready for announcement. Stay tuned, as Heather gave us some hints last night and it sounds very worthwhile!

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This work by Ted Roche is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States.