Diagnosing Connection Leaks in Node.js and Postgres

In building a website scraper with Chrome and Node.js, I made mistakes that led to connection leaks. In this application, the scraper runs in a browser and connects to a node.js server, which saves data off to a database. Once you know what the issues look like, they are easy to see, but otherwise often difficult […]

Advertisers referenced in Flippa auctions

The following data show revenue generating partners most commonly mentioned in Flippa auctions. This data is from approximately 76,000 auctions representing over 58,000 domains – note that in many cases more than one advertiser is mentioned per site. This is a broad section of revenue generation strategies, from CPC, CPA, affiliate sales, link sales, etc. […]

Adding Adzerk Units to Blogspot blogs

This applies to adding any html/js widget to blogspot, but in this case, we’re adding adzerk. Select “Layout” on the left hand side of blogger. Click images to enlarge. Select to add a new widget: Select the HTML/JS widget: Paste in the html code. Adzerk tells you to put this in the head block, but […]

How to fix “Error: NAMESPACE_ERR: DOM Exception 14” in Chrome

The only references I’ve found online are to an old bug in Chrome. Error: NAMESPACE_ERR: DOM Exception 14 I generated this with the following xpath expression generated by Firebug: id(‘content’)/x:div[2]/x:div[3]/x:div[1]/x:h2[2] This causes this javascript line to fail: document.evaluate(“id(‘content’)/x:div[2]/x:div[3]/x:div[1]/x:h2[2]”, document, null, XPathResult.ANY_TYPE, null) The fix is very simple: remove the namespaces – the “x:”, like so: […]


Fix to error installing “forever” for nodejs

After doing “npm install forever” in a VirtualBox instance you may get an error like the following. This is caused by running the install from a folder shared with the host machine. Certain file operations fail when crossing the machine/file system boundary in VirtualBox. npm ERR! error rolling back forever@0.8.5 Error: UNKNOWN, unlink ‘/vagrant/node_modules/forever/node_modules/winston/docs/winston/transports.html’ npm […]

Sample Greasemonkey Script in Chrome to process local files

The following script will fire an alert box for local files: // ==UserScript== // @name Matcher // @descriptions Match Local Files // @version 1 // @match file://* // ==/UserScript== alert(1); Save as “match.user.js”. Drop into a Chrome tab and you will be prompted to install. These are done per user profile. Each time you re-install […]

VirtualBox error indicating VT-X not enabled in BIOS

Creating a 64 bit Ubuntu VM on Virtual Box results in the following error: VT-x/AMD-V hardware acceleration has been enabled, but is not operational. Your 64-bit guest will fail to detect a 64-bit CPU and will not be able to boot. Please ensure that you have enabled VT-x/AMD-V properly in the BIOS of your host […]