Upgrading old versions of Postgres
By Greg Sabino Mullane
October 11, 2010
Old elephant courtesy of Photos8.com
The recent release of Postgres 9.0.0 at the start of October 2010 was not the only big news from the project. Also released were versions 7.4.30 and 8.0.26, which, as I noted in my usual PGP checksum report, are going to be the last publicly released revisions in the 7.4 and 8.0 branches. In addition, the 8.1 branch will no longer be supported by the end of 2010. If you are still using one of those branches (or something older!), this should be the incentive you need upgrade as soon as possible. To be clear, this means that anyone running Postgres 8.1 or older is not going to get any official updates, including security and bug fixes.
A brief recap: Postgres uses major versions, containing two numbers, to indicate a major change in features and functionality. These are released about every two years. Each of these major versions has many revisions, which are released as often as needed. These revisions are designed to be completely binary compatible with the previous revision, meaning you can upgrade revisions very easily, with no dump and restore of the data needed.
Below are the options available for those running older versions of Postgres, …
database open-source postgres bucardo replication
Seeking a Ruby, Rails, Spree developer
By Jon Jensen
October 9, 2010
This position has been filled. See our active job listings here.
Today I realized that we never posted our job announcement on our own blog even though we’d posted it to several job boards. So here it is:
We are looking for a developer who can consult with our clients and develop Ruby web applications. Most of our needs center around Rails, Spree, and SQL, but Sinatra, DataMapper, and NoSQL are lately coming into play too.
End Point is a 15-year-old web consulting company based in New York City, with 20 full-time staff developers working remotely from around the United States. We prefer open source technology and do collaborative development with Git, GNU Screen, IRC, and voice.
Experience with mobile and location-based technologies is a plus.
Please email jobs@endpoint.com to apply.
(This job has been filled.)
jobs-closed ruby rails spree
Surge 2010 wrap-up
By Jon Jensen
October 5, 2010
Following up on my earlier post about day 1 of the conference, here is an unsorted collection of what I felt were noteworthy observations made in talks at Surge 2010:
Web engineering as a separate discipline from computer science or software development started around 1999. It is interdisciplinary, involving human factors engineering, systems engineering, operations research, fault-tolerant design, and control systems engineering. (John Allspaw)
A real-time system is one in which the correctness of a system is tied to its timeliness. Eventual consistency is an oxymoron if timeliness is part of the data itself. Caching by CDNs can’t solve our problems here. (Bryan Cantrill)
Pre-fab metrics are worth less (and maybe worthless) when not tied to something in your business. Message queues enable lots of new uses because of the ability to have multiple observers. See Esper (Java, GPL) for live ongoing SQL-like queries of messages from AMQP sources, etc. (Theo Schlossnagle)
On scaling up vs. out: If your numbers show “up” is enough, be happy you can keep your system simpler. (Theo Schlossnagle)
Anyone can only ever know the past in a distributed system. There’s no such thing as global …
conference scalability
Two Cool Things about Liquid Galaxy
By Benjamin Goldstein
October 4, 2010
I. It uses COTS Hardware.
Liquid Galaxy is suitable for using with COTS (Commodity Off The Shelf) hardware. Yes, Google Earth itself is rather resource intensive, so it helps performance to use feisty computers (including ones with SSDs) but it’s still COTS hardware. Of course the very cool thing about using COTS hardware is that the price is right and gets better all the time.
II. A simple, elegant and powerful master/slave configuration and communication approach
Liquid Galaxy works by configuring its “slave” systems to have offsets from the point of view of the master system that the system’s user navigates on. The slave systems “know” their locations relative to the master system. The master system broadcasts its location to the slaves via UDP packets. It’s then up to the slave systems to figure out what portion of a Google Earth globe they need to retrieve themselves relative to the coordinates broadcast from the master system.
With this approach it’s easy to scale to a large number of slave systems. An interesting extension to this configuration and communication approach that the Google engineering team for the project provided for is the ability to configure one or more …
visionport hardware
Surge 2010 day 1
By Jon Jensen
October 1, 2010
Today (technically, yesterday) was the first day of the Surge 2010 conference in Baltimore, Maryland. The Tremont Grand venue is perfect for a conference. The old Masonic lodge makes for great meeting rooms, and having a hallway connect it to the hotel was nice to avoid the heavy rain today. The conference organization and scheduling and Internet have all been solid. Well done!
There were a lot of great talks, but I wanted to focus on just one that was very interesting to me: Artur Bergman’s on scaling Wikia. Some points of interest:
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They (ab)use Google Analytics to track other things besides the typical pages viewed by whom, when. For example, page load time as measured by JavaScript, with data sent to a separate GA profile for analysis separately from normal traffic. That is then correlated with exit rates to give an idea of the benefit of page delivery speed in terms of user stickiness.
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They use the excellent Varnish reverse proxy cache.
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500 errors from the origin result in a static page served by Varnish, with error data hitting a separate Google Analytics profile.
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They have both geographically distributed servers and team.
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They’ve found SSDs (solid state disks) to be …
conference hosting performance scalability
Google Liquid Galaxy Support
By Benjamin Goldstein
September 30, 2010
End Point is tremendously excited to announce our turnkey installation and support service for Google’s Liquid Galaxy. Google has just today announced the release of Liquid Galaxy to the general public and to its Earth Enterprise customers. Liquid Galaxy is an astounding 3D immersive environment for Google Earth. End Point’s turnkey installation service includes on-site booth construction, precise installation of compute nodes and displays, plus expert configuration of operating system, networking, and Google Earth client software. End Point also provides support for upgrades and troubleshooting.
End Point has extensive hands-on experience with installing and configuring Liquid Galaxy. We’ve installed a number of Galaxies for Google itself in the US and abroad. We also recently installed the Liquid Galaxy unveiled this month at the San Jose Tech Museum’s spectacular new Silicon Valley Innovation Gallery. This is the first Liquid Galaxy deployed outside of a Google office or trade show.
Google’s Liquid Galaxy is 3-dimensional without your having to wear funny glasses. Google’s reference implementation specifies a circular booth 12’4” (3.75m) in diameter with 8 large high definition …
company visionport
Gift Certificates: Easy to Say, Hard to Do
By Carl Bailey
September 29, 2010
A recent blog article by Steph goes through the steps taken to handle implementation of gift certificates using Spree’s coupon/discount model. At the end of the article, she rightly concludes that gift certificates are not that well suited to the discount model and need to be handled separately. Gift certificates are rightly handled as a method of payment—they should have no effect on the amount of the sale, sales tax or shipping charges. This is an attempt to further that discussion.
Some people want to put rules on to how gift certificates can be used: Minimum purchase, expiration dates, etc. However, these are rules that apply to qualification: Does the person or the sale qualify to get a lower price? To my mind, these are not rules that can be applied to true gift certificates. A gift certificate is a business liability. The merchant has the money, and the customer should be allowed to spend it as she sees fit, without having to pass any qualifications separate from those that apply to everyone else. So gift certificates should be treated by the system as a form of payment, and customers should not have to qualify just to use them.
To implement a gift certificate system, we …
ecommerce
Debugging jQuery
By Ron Phipps
September 28, 2010
A recent reskin project for a client requires that we convert some of their old Prototype code to jQuery as well as create new jQuery code. I have not done much with converting Prototype to jQuery and I felt like my debugging tools for JavaScript were under par. So this morning I set out to find what was available for jQuery and I found this article on the subject.
I’ve used Firebug for some time now, but was unaware of some of the supporting plugins that would certainly help with debugging JavaScript. Some of the plugins and methods found in the article that I found immediately helpful were:
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FireFinder: Makes it quite easy to verify that the selector values in your code are correct and that the proper elements are returned. I was able to immediately pinpoint problems with my selectors and this brought to light why certain events were not firing.
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Firebug Console: Using the console.log function allowed me to check values without littering my code with alert statements.
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FireQuery: At a glance this plugin for Firebug shows which elements have event handlers bound to them.
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Firebug Breakpoints: Setting breakpoints and watch statements in your code makes it easier to see what is …
environment javascript jquery testing