Programmer’s Toolbox Part 3: Consistent Hashing « tomkleinpeter.com Next up in the toolbox series is an idea so good it deserves an entire article all to itself: consistent hashing. Let’s say you’re a hot startup and your database is starting to slow down. You decide to cache some results so that you can render web pages more quickly. If you want your cache to use multiple servers (scale horizontally, in the biz), you’ll need some way of picking the right server for a particular key. If you only have 5 to 10 minutes allocated for this problem on your development schedule, you’ll end up using what is known as the naïve solution: put your N server IPs in an array and pick one using key % N. I kid, I kid — I know you don’t have a development schedule. Anyway, this ultra simple solution has some nice characteristics and may be the right thing to do. You’ll have a second problem if your cache is read-through or you have some sort of processing occurring alongside your cached data. As I said, though, that might be OK. In a nutshell, here is how it works.
42Registry External storage support — ownCloud Administrators Manual 6.0 documentation ownCloud provides the ability to mount an external storage device. The external storage devices serves as a secondary storage device within ownCloud. The ownCloud Admin has the ability to create such a mount. Note Using $user in any option gets replaced by the current user. Supported mounts The following lists the supported storage types. LocalAmazon S3DropboxFTPGoogle DriveOpenStack Object StorageSMB/CIFSownCloud/WebDAVSFTPiRODS Configuration Enable the app From the APPs Page within ownCloud, select External Storage Support and enable. Configure mounts As stated previously, the Admin has the ability to configure these mounts, as well as decide whether an end user can configure mounts for themselves. On the Admin page, scroll to External Storage: Enable users to mount their own devices In order to allow end users to mount their own devices, select the radio button next to Enable User External Storage. Local Storage This is used to mount storage that is outside ownCloud’s data directory Amazon S3
The importance of open online courses at OSCON 2014 Open source software is hugely important to us here at edX, since it's what we do all day, every day. Two weeks ago, the O'Reilly company hosted their annual OSCON convention in Portland, Oregon—a convention focused on open source software. Of course, we had to be there. So, my edX colleague James Tauber and I packed our bags and headed to Oregon for a week of learning and teaching to meet wonderful people, and to get excited about open source. I got to talk to a lot of different people, and many of them hadn't yet heard about edX, nor did they know much about MOOCs in general. Most people were interested in the course content available at edx.org. In addition to having conversations in the hallways, we also did more structured networking events. Finally, on the last day of the convention, James and I gave a presentation about Open edX: what it is, how it works, and how the community can get involved. OSCON was a lot of fun, but it's also very important.
Google’s Bigtable Distributed Storage System, Pt. I Google rolls out new applications to millions of users with surprising frequency, which is pretty amazing all by itself. Yet when you look at the variety of the applications, ranging from data-sucking behemoths like webcrawling to intimate apps like Personalized Search and Writely it is even more startling. How does the Google architecture manage the conflicting requirements of such a wide range of workloads? Bigtable, a Google-developed distributed storage system for structured data, is a big piece of the answer. Isn’t The Google File System The Answer? If It’s a Storage System, Where Are The Disks? This article is adapted from a paper entitled Bigtable: A Distributed Storage System for Structured Data(PDF) that was just released. Scale To Thousands Of Terabytes And Servers Every good product solves a problem. So, It’s A Database, Right? So It’s The Mother Of All Spreadsheets? So Far, I Get It. So Bigtable Stores Everything Forever . . . GFS. Comments, as always, welcome.
OpenStack untitled Overview The pfSense project is a free network firewall distribution, based on the FreeBSD operating system with a custom kernel and including third party free software packages for additional functionality. pfSense software, with the help of the package system, is able to provide the same functionality or more of common commercial firewalls, without any of the artificial limitations. It has successfully replaced every big name commercial firewall you can imagine in numerous installations around the world, including Check Point, Cisco PIX, Cisco ASA, Juniper, Sonicwall, Netgear, Watchguard, Astaro, and more. pfSense software includes a web interface for the configuration of all included components. There is no need for any UNIX knowledge, no need to use the command line for anything, and no need to ever manually edit any rule sets. Deployment Selection Hardware Unlike most common commercial firewalls offerings, the pfSense project is just the software portion of the firewall. Cloud
Four tips on how to sell open source software In the last 15 years of my career I have worked at several open source software companies, each with its own unique approach to software delivery, packaging, branding, and sales. Two things have become clear to me: There is no single best way to build a successful business around an open source software solutionSuccess depends on an organization’s commitment to building real-world solutions and its readiness to deliver genuinely valuable services that help customers to be successful with the solutions. Without genuinely valuable services for your customer, you have no revenue. I am aware that "value" is an overused word. Having spent many years of my career in marketing, I have been guilty of saying "what's the value proposition?" The following are four specific insights that are tied to selling and marketing open source software. 1) Selling open source software is actually about selling a meaningful solution bundle Thus, my task was to sell services. Is this scalable? Coda
Welcome rqr 5 best practices for community managers The role of community managers continues to evolve. I started to realize this after attending my first Community Leadership Summit earlier this year. My biggest take-away from it? Community management is an investment and its value is increasing. Heads up to employers: buy, buy, buy, and then invest some more. "Every year, the art and science of community management is becoming more predictable," said Jono Bacon, the Community Leadership Summit 2013 lead organizer. This year on Opensource.com, we interviewed several open source experts who have tremendous community management talent and experience: Greg DeKoenigsberg from Eucalyptus, John Mertic from SugarCRM, and Dave Stokes from MySQL. As a community manager myself, I reflected on what I learned this year at Opensource.com, particularly as we launched, evolved, and expanded our Community Moderator program. 5 best practices for community managers Avoid burnout—You've got to learn how to turn it off, unplug, and get offline.