As a follow on to an earlier piece about session management natively in Apache, I’ve written a follow up that looks more closely at the issue of developing sites that use cookies for ID and session management. In this article, I cover the mechanics, internals and security of the cookie system, and look at how to use cookies within Perl CGI scripts.
Here’s the intro from the piece:
As Web sites get more complicated and more dynamic, developers want to give users a more cohesive environment. This cohesion can provide all sorts of functionality, from a simple method of tracking a shopping basket to providing full-blown customization of stories, templates, and information shown to users as they use the Web site. The key to this system is the session - a unique identifier that enables developers to identify users, either for relatively short periods (e.g., in shopping baskets) or longer (full customization).
In a previous article “Session Tracking with Apache,” we described how to use cookies and the sessions system within Apache to track user access for the purposes of monitoring site usage in the logs and recording which pages were viewed. We can adapt the same basic principles - primarily cookies - through programmable components, such as Perl and PHP to provide customized Web sites.
This article will look at how Apache can help with session management and how that information can be used with Perl and PHP scripts.
Part 5 of the Building a grid with Web services series is now available on the IBM developerWorks site. In this part we cover the management and flow of information and work through the grid. This is the part where movies submitted to the grid are routed through to a suitable storage node according to their size and available storage capacity.
Here’s the official blurb:
Storing movies across a grid is more than just a case of handling the security and effective transfer of the information between system components. For the system to be an effective grid, you need to be able to manage the individual components and processes that make up the grid solution.
For example, when submitting a movie into the grid, there is more to the process than just transferring the movie. The grid manager must make a decision about which grid node stores the movie, then record the information so the movie can be located again when it is requested. You may also want to control individual nodes — for example, when upgrading the node or storage, you may want to disable it while you update the available storage locations. All of these items will be tackled in this tutorial.
And you may want to take a look at the previous parts before leaping into part 5:
Grid computing has made a slow, but steady, entry into the consciousness of the typical business user over the last four or five years. Often seen as a niche technology, usable in only a few very specific markets, Grid computing is now seen as another alternative to the problem of maximising computing power.
In a nutshell, grid computing distributes work over a number of machines. For the niche markets, grids are used for everything from computational grids for proteins and fluid dynamics, right up to the use by studios like Dreamworks which use grids to render the animations and special effects in many movies.
Grid computing has made a slow, but steady, entry into the consciousness of the typical business user over the last four or five years. Often seen as a niche technology, usable in only a few very specific markets, Grid computing is now seen as another alternative to the problem of maximising computing power.
In a nutshell, grid computing distributes work over a number of machines. For the niche markets, grids are used for everything from computational grids for proteins and fluid dynamics, right up to the use by studios like Dreamworks which use grids to render the animations and special effects in many movies.
The T1 CPU from Sun is a very different processor from the ones we are used to. The approach is not unusual today - multiple core chips are now common, including the Intel Core Duo that features in many new laptops and the multiple core offerings from AMD - but what is different about the T1 is the scale of the multiple core architecture.
Current T1s have eight cores, and are capable of running four threads, providing a maximum of 32 simultaneous threads off one CPU. To achieve this, the CPU is positively stacked, not only with the multiple cores, but also memory interface, cache and other components to, more or less, make a computer on a chip.
The T1 CPU from Sun is a very different processor from the ones we are used to. The approach is not unusual today - multiple core chips are now common, including the Intel Core Duo that features in many new laptops and the multiple core offerings from AMD - but what is different about the T1 is the scale of the multiple core architecture.
Current T1s have eight cores, and are capable of running four threads, providing a maximum of 32 simultaneous threads off one CPU. To achieve this, the CPU is positively stacked, not only with the multiple cores, but also memory interface, cache and other components to, more or less, make a computer on a chip.
I've just returned from a one week (and I mean 7 days, not an easier 5) development conference and, as always, I have all the issues of getting back into the groove - including over 9000 items in the RSS feeder. Luckily I was able to stay on top of the email this time, so apart from a few non-critical accounts, I am more or less up to date.
More of a problem this time, I would say, is the state of my health.
First of all I'm tired. Officially the conference was from about 9am to 5pm, but with everybody in the same hotel meetings really started at 7am with breakfast, and ended at whatever time you finished dinner. Some nights this was late as midnight or 1am.
I've just returned from a one week (and I mean 7 days, not an easier 5) development conference and, as always, I have all the issues of getting back into the groove - including over 9000 items in the RSS feeder. Luckily I was able to stay on top of the email this time, so apart from a few non-critical accounts, I am more or less up to date.
More of a problem this time, I would say, is the state of my health.
First of all I'm tired. Officially the conference was from about 9am to 5pm, but with everybody in the same hotel meetings really started at 7am with breakfast, and ended at whatever time you finished dinner. Some nights this was late as midnight or 1am.
Rod Hamilton has made a valid point here on the approach offered by Sun with the Solaris and OpenSolariis operating system and it is affecting the way in which Microsoft (and others) will do business in the operating systems space.
I have argued this point many times before here on this blog, and elsewhere. Sun have made an amazing strategy choice, and it is one that other companies are making good use of, and one that some proponents of the FOSS model applaud.
Rod Hamilton has made a valid point here on the approach offered by Sun with the Solaris and OpenSolariis operating system and it is affecting the way in which Microsoft (and others) will do business in the operating systems space.
I have argued this point many times before here on this blog, and elsewhere. Sun have made an amazing strategy choice, and it is one that other companies are making good use of, and one that some proponents of the FOSS model applaud.