Wednesday, February 16. 2011
Occasionally friends, relatives, and clients ask me what they should do about creating and hosting a web site. When this happens, I find myself repeating, well, myself; so I thought I would put my thoughts on virtual paper for future reference. I will post a notice on this entry if my recommendations change at some future date. If you would like to consult with me about your particular setup, please contact me for consulting rates and availability.
Ok, you want a web site, good. First, get an idea of what your website will contain, how big it will be, what kind of content you will serve, and how much traffic it will receive. Will it DO something or SHOW something. If you're just starting out, or have no idea, any of the recommended plans will let you scale size and traffic for additional monthly fees, so don't worry too much about it.
If your goal is an informational, mostly text, but low volume, web site, just get a BlogSpot.com or other blog hosting account. They are free, minimally annoying, and with free image galleries and video hosting sites, can link to or embed video and photo content too. My Ward (a congregation in the LDS church) has a few of these sites for various extra activities, for example the youth group is presenting a "Fancy Dance" and Dessert Auction on Saturday Feb 19, 2011 to raise money for camp and activities this year, and uses BlogSpot to advertise. By the way, everyone is invited to the dance, and babysitting is provided, see the site for more information.
If your goal is to sell something, sell through the Amazon marketplace or Etsy.com if the products are crafty. Piggyback on top of an existing marketplace to jump start sales. If you're too big for that, I don't really have any advice. I don't have any experience in that space. I think that I would look for a host that provided merchant services (credit card processing for example) as part of the package.
If your goal is to host a medium volume dynamic application, use WebFaction. WebFaction is probably the best Shared Hosting service there is. They're one of the very few hosting providers that embraces Python application hosting, and I've run Pylons, TurboGears and CherryPy applications there. The hosting is cheap, fast, and it stays out of your way if you want it to. I host this blog, my personal e-mail and my business website on the base level account. I also host demo sites for clients when needed. The email service isn't spectacular, but it's functional as long as you have client side spam filtering like what is provided by Thunderbird. I like it because there are no set CPU limitations, the memory allotment is generous (email, OS, and even Database memory usage doesn't count against your quota, though the disk usage does), and the base disk space/bandwidth allocation is substantial. It also helps that WebFaction takes care of all data backups and operating system and hardware maintenance for you. WebFaction has one click installers for a large number of applications, so you don't have to know very much about Linux to get started, but if you do know what you're doing, you have SSH access, and everything that comes standard with a Linux shell account.
If you are planning on building a new application, take a look at Google App Engine. It lets you get going and host up to a certain threshold for free. Scaling up can be done fairly reasonably. Applications developed for App Engine can be run independently of Google, so you are not necessarily locked to Google as your hosting vendor.
I do not recommend any kind of Virtual Private Server hosting that isn't bundled as a Cloud offering. I've used three different VPS services, and two have all been slow and had high network latency (the third, Slice Host was bought and extended into Rackspace's cloud services, which I recommend below). Higher volume sites may do OK, but if the CPU, IO or Memory usage is too high for too long, your VPS can be rebooted or shut off. What this translates to is that you would have to hit a very small sweet spot to get good performance out of a VPS without getting shut down. Better hosting options exist.
If you do need system level access to a server of your own for some reason -- if for example you have an email processing system as part of your application -- or if you have requirements that extend beyond a single host, like high availability, then using a Cloud based VPS is desirable. Cloud computing nodes are designed for high performance application hosting. The overhead of virtualization is minimized by the use of advanced virtualization techniques (paravirtualization, CPU instruction sets, etc.) and by dedicating virtual resources to physical hardware. The management tools are typically excellent and, in the case of my two favorite cloud providers, there is an inherent benefit of a content delivery network (CDN) and Storage Attached to Network (SAN) which can serve as a scalable long term application storage or system backups. These two tools are used by very large websites to deliver content faster and more efficiently, and they're available on the Cloud for even the lowest rate plans. The intro level computing node at Amazon Elastic Compute Cloud (EC2) starts at 3¢/hour. Rackspace however has a node that start as low as $10.95/month (that's about 1.5¢/hour). There aren't as many third party software developers, and no external image providers (as far as I know) for Rackspace, but they have pretty good management tools, and a pretty good selection of base images to get you up and running pretty quickly.
EC2 was built for running short-lived computing (i.e., processor intensive) tasks, and it's pricing model and instance sizes reflect that. The instances and costs are very competitive to people looking at dedicated hosting. Rackspace's cloud is similarly designed, but has smaller instances, so it is cheap enough to use as a substitute for VPS or even shared hosting.
A former coworker of mine recently signed up for EC2 to host his blog using a promotional deal offered by Amazon's EC2. This deal lets you use the Micro instance for up to 750 hours per month for a whole year. Thereafter he's looking at a starting monthly rate of $21.60 plus storage and bandwidth charges. Of course using a Cloud node to host a blog is seriously overkill (as evidenced by his load average) unles he is doing much more with his site than visible at first glance. If he is uncomfortable with a free or even a paid blog hosting account, either WebFaction or Rackspace Cloud would be sufficient to host his site at about half the cost of EC2.
There is also dedicated hosting, but with the price point and performance of EC2 and Rackspace Cloud, you'd have to be very big indeed, or have special criteria not available for cloud nodes for the benefits to outweigh the costs.
Here's what I use for myself and my clients, and why I don't recommend VPS hosting:
As I mentioned above, I currently host my blog, email and business website on a WebFaction Shared Hosting plan. Shared Hosting starts at less than $10/month, with steep discounts for prepayment. I moved all the services off my VPS at Linode and shut it down since WebFaction was working so well. I found Linode to be sluggish and and network traffic to be high latency, but haven't felt that way about Webfaction.
With InMotionHosting's VPS offerings, performance was similar to or worse than Linode's. I had a client on the fully managed VPS plan costing $90/month. The VPS would bog down during traffic peaks and InMotion's system administrators would reboot the box (without any advance warning, without notice after the fact and without explanation of why). When things were peaceful, trying to log in to SSH could take 30-45 seconds, page loads for the main site or core application could take several seconds in spite of caching and being rather lightweight. InMotion always seemed to want to upsell to dedicated hosting when I mentioned the problems to their customer service representatives.
This site/application just passed through its busiest season on a Rackspace Cloud Server instance, and the it never even hiccuped. Final cost for hosting for the month? $24, and plenty of room to scale up if volume increases. I recommended the Rackspace Cloud Server because the application has an email processing system and the client has clients that could have been squeamish if their customers' names and email addresses were available on a shared host's shared database server (even though the database itself was not shared and was password protected).
Friday, January 29. 2010
So I did some digging around after giving my off-the-cuff lightning talk at TriZPUG tonight and it looks like some other ex-rpathers (Thanks Dugan and Gafton!) have forked epdb. There's also the the rPath tree synchronized from here but this tree is missing some of the latest changes. The dugan tree is "python setup.py installable" now, instead of using make, and some shortcut documentation has been created, so I don't have to make this post as long as I thought I was going to have to.
For those who didn't see my little demo, epdb is like pdb (the standard Python debugger), but it adds multi-line text input, history and tab completion, nested debugging from the debug prompt, shortcuts to introspecting code, and a very nice post mortem debugger. Last, but not least, it also contains a server and client for remote debugging. The docs are still pretty sparse, but hopefully more attention can help fix that. I'd also be happy to answer questions about it.
Thursday, December 31. 2009
Thanks to Chris Calloway, TriZPUG has a planet now. I don't know why it's taken me so long to connect with this group of people (I've been working with Python for 5 years now), but it's a pretty cool group from what I've seen so far. Thanks for making me (a TurboGears guy) feel welcome among all you Zope/Plone/Django developers.
Wednesday, December 2. 2009
Due to several shortcomings of the stock formencode email validator, I forked it and extended the test suite. This fixes the two most glaring issues I know of, namely the inability to handle unicode strings (international domains), and several problems with input checking (e.g., allowing commas) where invalid e-mail addresses make it through.
I did not write most of the code, I just refined it and added tests to exercise it. Let me know if it's useful to you, and if you find problems with it.
Saturday, July 26. 2008
Dear lazy web, can you point me in the right direction?
Monday, March 17. 2008
I just returned from PyCon 2008 in Chicago, where I connected up again with a few people I met last year and met a few new people. Rather than write a travelogue, I'll just highlight a few of the main things that I learned/did.
It looks like some of the niceties of Zope2 are going to leave the silo under the Repose project. This means that the zope transaction manager (repoze.tm), retry engine (repoze.retry) and other zope features can be used by your WSGI application. Also it means that Zope can be hosted as a WSGI app.
I learned there are ways to extend _import_ that don't involve rewriting _import_. I don't know if I'll ever need to know this, but it might be useful in a plugin loader of some sort. There's a flow chart in Brett's SVN.
I should probably use more weak references in my Python code. Dr. Tim Couper gave a lucid overview of references weak and strong, and practical ways of dealing with circular references, including how to detect them using unittest. I hope he posts his slides soon.
Tahoe is a nifty looking distributed remote filesystem concept. It needs fuse drivers though before it's really a filesystem rather than a storage mechanism (like S3). It's all RESTy though, which makes some people happy.
There are metrics for measuring code complexity, and python has tools to do that. Basically every branch in a method increases complexity by one. Keep complexity down to 10 or less to make unit testing feasible. More than 10 and the number of unittests required to cover every branch starts to get unmanageable. Apparently there is a PyMetrics module for measuring code complexity. Here are the slides from a very interesting talk.
I held a BoF on i18n'izing web applications, and a few people helped me to brainstorm this problem. The general consensus was that you should do translation as close to the user as prudent; view certainly, controller is ok, but never in the model, if you have messages that are generated by some other process, or that gets cached to the database, the "data" should be stored separately from the operational message. Generally you should avoid sending this kind of data to the end user, and instead abstract it with messages of your own. Barry Warsaw came in to the BoF with a hard problem; usually when you're handling web templates, you filter out the non-element text and build a string table out of that. What about the cases however, where you have <em> or <b> tags? I think that if you had an XML parser that would extract the text elements, and if sub-elements are present lump them with the text. For example, if you had "This text <b>needs</b> to be translated", it would be collected as one string, but if you had "<div><span>Phrase 1</span><span>Phrase 2</span></div>" it would be two phrases.
There are a couple of cool tools that have stemmed from the PyPy project. The first offers a framework for distributed testing. Py.test does stack introspection so that simple "assert" statements can be used instead of the pseudo self.assertEquals().
I got together with some people to talk about Python Packaging. Here are some notes from the meeting, and there's been some additional discussion on the distutils-SIG mailing list. Jeff Rush did a tutorial on Thursday, and his slides and exercises are available. Hopefully something coherent comes out of this, but it looks like more of the same resistance to making application installation reasonable.
I talked briefly with Ivan Krstić and Noah Kantrowitz about python plugin frameworks. Hopefully we'll be able to collaborate some on a generic system for application extensions.
Probably the coolest thing I learned about was a couple of protocols, both implemented by orbited. Orbited's client libraries allow for a user to connect to a orbited server to provide a push mechanism for sending messages to a web browser. The Orbited team was shooting for a 0.4 release after the PyCon Sprints this week. Check out their IRC client demo.
PyCryptoPP was suggested to me as a decent Python based Crypto library, since it's simply python wrappers for Crypto++. PyOpenssl has a new maintainer, and should be getting some much needed attention.
I also enjoyed Raymond Hettinger's talk on "Core Python Containers". It was very helpful in understanding what list, dict, deque and set do behind the scenes, and how to use them most efficiently.
Overall, I had a great experience at PyCon 2008. The venue was big enough for all of us (there were more than 1000 registrants), and there was more than enough room for Open Space/BoF talks.
Chicago style pizza is definitely different from anything I have eaten before. The jury is still out as to whether it's worth the hype.
Monday, February 26. 2007
Last night I returned home after 3 days at PyCon 2007 in Dallas Texas. I think my brain is full. It was great to meet people to whom I've talked on IRC or email, or whose software I've used. It was also fun to hang out with Mark Ramm, Robert Brewer, Ian Bicking, Ben Bangert, Rob Orsini and Chad Whitacre at Robert and Chad's suite on Friday night. I haven't laughed so hard in a long time.
As Robert mentioned in his blog post, there was some mind melding, er, meeting on the part of Zope, Pylons and CherryPy as well as others. I'll look at the way that sockets are handled and contribute some code. I'm looking forward to this collaboration. In addition to what Robert mentioned another thing we decided was to come up with several "stories" for deployment and help guide users down the right path for them when deploying a Python web application.
For the rest of the conference, most of the keynote and full length talks were good, the lightning plenary talks were great, having several rooms to hold Birdts of a Feather (BoF) or non-scheduled talks provided much enlightenment, owning an 802.11A wireless chipset was a difference maker in connectivity and bandwidth, and lots of Pythonistas have beards (some of which are out of control)
I noted several things that I thought merited additional attention:
Hopefully I can make it again next year.
Wednesday, November 1. 2006
I've been able to package all of TurboGears 1.0b1 with Conary. And with the new release of rBuilder Online, Xen domU images can be generated just as easily as VMware images. You can download images for Xen, VMware, Qemu, or Parallels here. Please let me know if you are interested in install CDs, and I'll generate them to add to the release.
Saturday, September 16. 2006
Tuesday, August 29. 2006
So my last entry, oh so many moons ago, mentioned that I was working on a new project. Now that that project has been released, I can talk about it, but better yet, how about an article about rPath Linux, what we're doing, and the rPath Appliance Agent (or rAA) which I helped design and build.
A little bit about rAA itself; it provides a pluggable framework for system configuration tasks, like setting up networking, setting the root password and checking for and applying software updates. There are some screenshots of rAA in action linked from the eWeek article above. rAA is written in python and built around TurboGears, a web application framework for RAD and MVC web development using Python.
rAA is Open Source Software, released under the Reciprocal Public License. A conary package group that can be added to a rBuilder Project to insert rAA into your own custom software appliance is available from the rAA Project.
Some basic documentation for rAA is available here. It's built with rPath Linux as an assumed installation platform, but several appliances have rAA built-in, and have VMware images available so you can try it out without installing a new Linux distribution.
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