context
There are 14 entries for the tag context
Knowing the algorithms is only half the battle, you’ve got to understand a whole lot more to design a scalable architecture.
Citrix’s Craig Ellrod has a series of blog posts on the basic (industry standard) load balancing algorithms. These are great little posts for understanding the basics of load balancing algorithms like round robin, least connections, and least (fastest) response time. Craig’s posts are accurate in their description of the theoretical (designed) behavior of the algorithms. The thing that’s missing from these posts (and maybe Craig will get to this eventually) is context. Not the context...
If you aren’t using all the security tools at your disposal you’re doing it wrong. How many times have you seen an employee wave on by a customer when the “security device enclosed” in some item – be it DVD, CD, or clothing – sets off the alarm at the doors? Just a few weeks ago I heard one young lady explain the alarm away with “it must have be the CD I bought at the last place I was at…” This apparently satisfied the young man at the doors who nodded and turned back to whatever...
Vertical scalability used to require optimizations inside the application, at the code level. Cloud computing changes the nature of vertical scalability and, one hopes, will lead to a new model of scalability based on the capabilities of Infrastructure 2.0 and increasingly granular resource management capabilities. RightScale recently offered up its own analysis of Amazon Usage Estimates and while the details they provide on Amazon usage from their vantage point is very interesting I found one of their related observations even more fascinating: In earlier days the predominant method of scaling was by...
Mobile devices may still be somewhat awkward in terms of supporting rich, web-based applications but they are leaps and bounds ahead of most infrastructure in their ability to figure out where you are. GeoLocation technologies used to be used by load balancing solutions to address poor application performance across high-latency connections such as intercontinental and satellite links. While this is still an important variable in assuring application performance, especially for very large sites, GeoLocation is increasingly used to comply with legal restrictions on broadcasting, export of data and applications, and to provide more relevant information to users than...
Are you load balancing servers or applications? Network traffic or application requests? If your strategy to application availability is network-based you might need a change in direction (up the stack). Can you see the application now? Network load balancing is the distribution of traffic...
Logs are for auditing, accountability, and tracking down offenders – not for providing real-time security A new law signed into effect in February 2009 requires that health care providers and organizations subject to HIPAA notify affected customers in the event of a breach affecting more than 500 records. There was very little discussion of this new requirement in the blogosphere which was surprising given this statement hidden amongst one of the few articles on the subject. Dominique Levin, executive vice president of marketing and strategy for log management vendor LogLogic, told SCMagazineUS.com...
Context, it’s always about context (or the lack thereof) I received a call recently that most people have probably received: our banking institution just wanted to verify that yes, that was Don or I making purchases at midnight in Wisconsin and then later in Indiana and yet again that afternoon in Ohio. That’s a good thing, I’m sure, as they’re just trying to watch our back. But later in the day I tried to make a purchase and was, horror of horrors, denied. The bank, when called, seemed matter-of-fact about the situation. The security flag hadn’t been...
The concept of an “intercloud” is floating around the tubes and starting to gather some attention. According to Greg Ness you can “Think of the intercloud as an elastic mesh of on demand processing power deployed across multiple data centers. The payoff is massive scale, efficiency and flexibility.” Basically, the intercloud is the natural evolution of global application delivery. The intercloud is about delivering applications (services) from one of many locations based on a variety of parameters that will be, one assumes, user/organization defined. Some of those parameters could be traditional ones: application availability, performance, or user-location. Others...
The importance of context in solving the problems created by tying web applications to deeply rooted local metaphors (IP addresses). The relationship between IP addresses and web applications to most end-users is much like the metaphorical language of the Tamarians in Star Trek: The Next Generation “Darmok”. It is incomprehensible without the proper foundational concepts; to anyone who lacks the proper context. In the case of IP addresses and web applications that foundation is technological rather than the historical basis of the Tamarian’s metaphorical language. The diseconomy of scale inherent in our reliance on IP addresses...
What is this application delivery thing that everyone keeps telling me I need? Isn’t that just the latest marketing term for load balancing? A recently released Forrester report concludes that “firms must develop and integrated strategy for application delivery.” We don’t disagree with that, or with the Gartner report claiming that “Load Balancing is Dead, Time to Focus on Application Delivery.” Application delivery is the next step in the logical evolutionary path from the tactical solution of load balancing to a comprehensive application infrastructure strategy. Forrester’s research indicates that despite the fact that application...
Decisions about routing at every layer require context A friend forwarded a blog post to me last week mainly because it contained a reference to F5, but upon reading it (a couple of times) I realized that this particular post contained some very interesting information that needed to be examined further. The details of the problems being experienced by the poster (which revolve around a globally load-balanced site that was for some reason not being distributed very equally) point to an interesting conundrum: just how much control over site decisions should a client have? Given the...
Mike Fratto loves to tweak my nose about web application security. He’s been doing it for years, so it’s (d)evolved to a pretty standard set of arguments. But after he tweaked the debate again in a tweet, I got to thinking that part of the problem is the definition of web application security itself. Web application security is almost always about the application (I know, duh! but bear with me) and therefore about the developer and secure coding. Most of the programmatic errors that lead to vulnerabilities and subsequently exploitation can be traced to a lack of secure...
You're standing in line at the bank when someone walks in. You instinctively look around and notice the newcomer is wearing sunglasses, and a hooded sweatshirt. His hands are both inside the pockets of his sweatshirt, even though it's warm inside. He chooses a line, and dances nervously from foot to foot, craning his neck to see to the front of the line. After a few minutes he leaves the line and chooses a new one, growing increasingly agitated at the wait. He keeps looking from the clock to the line to the tellers, and appears to be wringing his...
If you're excited about the automation capabilities of cloud computing and virtualization, you are going to love this solution. In a virtualized environment where applications can ostensibly be popping up all over, and applications are no longer tied to specific servers, there is a need to automatically manage these application instances in a high-availability (load balanced) environment. What you need is the ability to automagically add and remove application instances from the application delivery controller (load balancer) so you don't have to worry about tying those applications down, which could reduce the benefits typically associated with virtualization. If...
