What would be a proper way to simulate a large number of requests to test if my web application can handle it?
You could try using Microsoft's WCAT tools. Look here: http://support.microsoft.com/kb/231282
They're free, too. That's always nice.
Depending on your budget, you may be interested in some load testing software designed for this. A Google search brings up all sorts of alternatives. This is probably the best way to do it.
This one has a free trial version and isn't too pricey, but I would recommend shopping around first.
I've used JMeter in the past, and I find it to be very useful for stress/load testing as website, even ones written in ASP.NET (with or without MVC).
In general you would want to (with any tool) write a script of what an average user of your site would do. You may even end up creating multiple of these scripts. Tools like JMeter even allow for a random element to be added to a script. With these scripts created a load testing tool can then simulate as many users as you desire hitting your site.
I would recommend allow JMeter to slowly ramp up the number of concurrent users and watch the response time graph. At the point where the response time starts increasing too highly is at the point where you've hit the maximum number of users (given you scripts) that your site can handle.
ab and httperf are two, more unixy options, if you don't mind delving in that direction.
There's a nice screencast for using httperf by peepcode.
Use the load testing tools from Visual Studio Team System. 2010 if you can get it.
The tools are great to use and provide wonderful instrumentation. There is also a programming model to go with the tools, allowing you to make some very complex testing scenarios possible.
Post the URL on stackoverflow.
Make it sound like a challenge, so lots of people come check it out: "Can you find the hidden performance problem in this app?"
Related
Possible Duplicate:
What Web Application Framework for Delphi is recommended?
We have a Delphi 2007 desktop application which we have hosted using Citrix. Now we want to get rid of Citrix and somehow web-enable it.
I have done bit of research and found that it is possible by using the uniGUI.
http://www.unigui.com
Conclusion: Can be done, but would require a re-write and only a subset of components are supported. Serious questions remain are the monolithic application structure in a web environment.
There are two more options morfik and atozed and they also require a re-write.
I want to know if there is any other option which requires a very less re-write work and how fragile is it?
How fragile it is, is based on the quality of your code. If you have a good structured application, with business logic and data access fully separated from the GUI, it will be pretty safe, although you still have to rewrite mostly all your GUI.
If there's logic in your forms, and the code that talks to the GUI components is intwined with the code that checks your input and stores the data, then you have a big problem.
In that case, this is a great opportunity to refactor large portions of your app and do it better this time. ;)
Since there is no "silver bullet" here, it doesn't matter much which product you use. You have the same challenges with any of them. I would recommend spending a few days on a Proof-of-Concept (PoC) re-write of 2-3 typical screens. Implement the POC for each "finalist" product, and see how it works out. Keep track of how long it took for each one, things that were easier/harder, and how the end result appears to the end-user (performance, good/funny-looking, robustness, "feel").
As for the actual re-write, I would recommend the following:
Re-factor existing application to remove business logic from the UI.
Full Regression testing, and push that into production.
NOW proceed with conversion to one of the web tools.
Oops - I left out a step. Step 0: FREEZE all features/fixes. If fixes are needed to current production, they'll need to be done in a separate branch, and then rolled-up into this project later.
Note that this type of work lends itself nicely to outsourcing, as the work is straightforward and the requirements are simple. Especially if it can be delivered one form at a time, so progress, timelines, and $$$ can be measured in small chunks.
Another preliminary step is to develop a "cook book" for stripping the business logic from the existing GUI layer. It should identify naming conventions, common libraries (for code that should have been shared all along but wasn't), and should describe the conversion methodology.
AFAIK, there's not tool will convert your desktop application to web application without requiring rewrite for most of GUI Parts.
as Golez said, you will have to refactor your application, try to separate your business logic from the GUI, then you can use some tools like Intraweb to develop the GUI as web and reusing the existing business logic with it.
Another option by converting your application to n-tiers technology and warp your business logic as web services or any open technology and make your web part by any web languages such as ASP.Net or PHP.
Depending on how 'Web enabled' you want the App to be.. I use Cybele Software's (https://www.cybelesoft.com/) Thinfinity UI to extend Apps to the Web, including Database Apps.
It only requires the installation of their ThinFinity Server and one line of code added to the Proj source and you are in business.
The Apps all run on your PC.
Well perhaps I simplified it a little, but worth a look.
HTH.
Regards,
Ian
Clarification/summary for the question -- we're looking for:
a hosted bug tracking system,
that is as convenient to use as lighthouse/github/launchpad,
can deal with attachments,
integrates email notifications and operations (implies operations in commit messages),
has a script-friendly API,
allows anonymous bug reports, or ones with an email but that do not require setting up an account for submission.
Lighthouse is close but fails on the last point, launchpad is similar, github also doesn't handle attachments. Tender is great for the last point, but fails as a general bug tracking system (and it looks like its open-source version will be limited to basically being a forum).
We looked into a number of applications to install and setup -- but with this range of requirements, they are always coming with a huge cost in terms of investing time in setting up and maintaining a working system.
In our (open-source) project we have been using Gnats for a really long time. It doing what it was designed to do fine, but that's getting to be pretty inconvenient: it's no longer maintained, has features that we never use, and lack features that we'd want to use... It doesn't deal with attachments, has no easy way to perform actions via emails, no integration with commit messages, and a web interface that was designed for 90s browsers. So I've been looking around in an attempt to find something that could replace it, hopefully some hosted solution to avoid the setup/maintenance hassle.
Probably the most impressive tool that I've seen is lighthouse: it has a very nice and practical interface, properly deals with attachments, controllable via emails, and can respond to commands in commit messages. But... It doesn't have any sane way to submit a bug anonymously -- and that's a major requirement, since we need any random user to be able to submit bugs through our IDE. (It seems that there is a possible hack to forward an email faking the From field, but that doesn't work very well -- specifically, the reporter should be included in the followup email exchange.) On the other side, there is the related tender tool, which is very good in that area, but is very basic otherwise -- too basic to serve as a bug tracking system.
There's a whole bunch of other sites that I've tried -- it seems that all of them require submitters to have an account, so they don't work well for our needs; as well as being limited in various other ways (don't deal with attachments, no good email integration, etc etc). It doesn't help that the meta-descriptions of these sites is usually pretty obscure: it took me hours to just figure out what tender/lighthouse are and how they're related, and no site mentions its inability to receive bug reports without registration. (I'm looking only at open-source-friendly sites, since we don't have any kind of budget for such things.)
There's also the option of installing some system locally, but bug tracking systems tend to be monsters that I'd like to avoid configuring and maintaining, if possible.
So the question is: is there anything obvious that I'm missing? Or to make it more concrete: is there a good comparison page somewhere that lays out popular options and their respective features explicitly?
JIRA is free for open source projects. It's far more user friendly than trac and bugzilla, and allows anonymous submissions and plugins. Unfortunately you'll need to host it on your own server, but from personal experience I can tell you that all you need to do is install a database (it can run without; but that's not a good idea) and it basically maintains itself.
Also is there a particular reason why Google Code or Sourceforge issue tracking tools wouldn't work? You don't need to use all their services if you don't want, you could use them purely for issue tracking.
Did you try trac? It is used by many open source projects.
FogBugz is one option. They'll host or you can run it yourself. My company looked at it but ... political considerations ... meant it is not viable here.
Have you looked at this Comparison of issue tracking systems on Wikipedia?
I have also found fixx, by hedgehoglab. Apparently it has the features that you care more:
Get things done
fixx has an intuitive interface to enable quick bug
reporting. Filling in a bug report is
as easy as sending e-mail.
Ability to add multiple attachments to issues allowing you
to attach screenshots and manage
documents related to issues.
Clever notification options to keep relevant people informed while
preventing issue tracker spam.
Also:
It has an open REST API.
I see that you are using Subversion as SCM. There is a Subversion integration with fixx.
Its unique installation requirement is Sun JDK 1.5.0.
It seems free for Open Source Projects and an hosted version is "Coming soon".
Note that I have never used it, so I cannot give any recommendation.
The open source BugTracker.NET has support for the following areas that are giving you problems:
Attachments
Guest login
Email notifications
SVN commit integration
I found it easy to set up, maintain, and tweak. Of course, you might think otherwise if you are not familiar with .NET and have a Windows server available.
You might look at Unfuddle. They do allow an API for the submission of tickets and have your other points covered including attachments.
Take a look at repositoryhosting.com They have ready made solution with trac / svn / git, for you. Comes with all kinds of bells and whitsles, such as Agilo plug-in and auotomatic backup to the amazon S3 bucket of your choice.
The prices are very reasonable.
Also, jumboxes offers a Trac / SVN virtual appliance that you can host in your own environment.
Redmine is a good open source option. You can check an online demo and a list of features.
It's not hosted though. But it's an interesting option.
And you can always check a list of different open source bug tracking alternatives
I've used ZenDesk in the past and it was rather hassle free.
In addition it has an api: http://www.zendesk.com/api.
Moreover I KNOW it can CC whosoever you want it to whenever anything happens.
We too are looking for a new solution.
At present we're using FogBugz, which is painfully slow.
We need our customers to be able to log bugs via email. Tender looks perfect, with the exception that it doesn't have any obviously usable ID fields that we can pass around. Is there a plugin or similar? I could knock up a browser extension to "goto bug id [whatever]" but that seems kludgy for what should surely be a core feature?
This question contains a lot of background information, to make sure you fully understand why we are looking at these technologies.
The question is basically this:
For a large, spreadsheet-type, module that we need to develop for our webmodule for our application, are there any pitfalls we should know about if we decide to use Silverlight for it?
Issues we already know, and don't need any discussion/reminders about:
We're aware of the problems around using a plugin-type solution, which may or may not be installed on the users machine (and in some cases, probably can't be installed). These risks needs to be mitigated, but we're aware of them. Please don't get hung up on this.
We're a .NET company, so while ruby on rails and lots of other different platforms and architectures are good for this solution, they are not in the scope of the decision here. We have lots of code already written in .NET that we need to take advantage of, otherwise the project will never be finished regardless of platform.
Background
We have a web module for our application with employee-related information and some input forms. Our Windows desktop application is mostly a department leader type of application, to manage employees, but the web module contains mostly employee-centric functions. The web module contains mostly report-type webpages, to list information from the system, or input-forms.
The module we need to add now is more of a heavy spreadsheet type application. You change something one place, and something changes somewhere else, like sums, what is enabled/disabled, etc.
We know we can manage all of that with AJAX, but another issue here is that the application will potentially load a lot of database data in order to put the data in front of the user, and with a AJAXy solution, we're afraid that the request/response method here will have to reload quite a lot of information on every request, even to respond to seemingly easy questions.
A way to mitigate that would basically be to load information into a Session-object or similar, but that's a big no-no, so we'd rather not do that. This is a multi-user module, and some of the data is rather static, but some of the data is also going to have to be refreshed from time to time, so if 10 users loads a lot of data into the session, that's going to be a pretty big memory-hit.
We will be using ASP.NET (MVC) for this if we choose to go this route, that is, developing the module in pure HTML and similar technologies.
Then we looked at Silverlight, and would then load all the information down into the Silverlight application on the client. It would hold the current state, and would only need to touch the database to refresh some of the information, some of the time, instead, as we think the request/response model with ASP.NET (MVC) would work, on every little request.
But, since we have only done minor things with Silverlight, we're not that experienced with it, and we're afraid that some assumptions we might have, stated or unconcious, turns out to be wrong or flawed, which will make this project impossible or very hard to manage at some point.
For instance, just to take an example, is there a limit to how much memory the Silverlight application is allowed to load (I know, if I have to ask I can probably not afford it), for instance if there is a limit on 10MB, then that would be nice to know about before we're midway and start to load the really heavy data.
To make it simpler to give examples, let's just assume we're building a spreadsheet, that has so much data, that for the simple "changed a number here, what else changed", too much data from the database has to be loaded for a proper request/response model to be used, and if we move the entire thing to Silverlight, what will make that project hard or impossible?
Knowing about such things would at least give us the ability to consider if the price is acceptable.
In short, why should we not use Silverlight for this and instead go for ASP.NET (MVC)?
And again, "use Ruby on Rails instead", is not really an answer here. The options are ASP.NET (MVC) which we have experience with, or Silverlight which we don't but can gain.
Of course, if Ruby on rails, given that we'd have to start pretty much from scratch infrastructure-wise, and have to learn a new programming language, and framework, and download and learn a new IDE/tool, if it would still allow us to cut the development time in half, then please give us some information about how that might work, but I daresay that won't really happen here.
You should know that Silverlight (version 3.0) does not support any printing whatsoever, which to me sounds like a whopper of a showstopper for you (sorry, I couldn't resist). The good news is that full printing support has been added in version 4, but that is still in beta. Rumours say it should be out before the summer if everything works out according to plan, so if that fits with your roadmap I would use SL4 right from the start.
There are no memory limitations in Silverlight, but for the local storage (IsolatedStorage) mechanism there is a default limit of 1MB. But you can easily get around that by asking the users permission to increase the local storage space when he/she starts up the application. More on that here: Silverlight Tip of the Day #20 – How to Increase your Isolated Storage Quota.
(Edit)
Aside from the missing printing functionality that will be fixed in SL4 I cannot see any problems with your scenario. I would easily take the Silverlight route if I were you, especially since you already have extensive knowledge of .NET/C#.
For a rich interface as you've described, I would definately go with Silverlight or Flash rather than a html/javascript/ajax solution.
These technologies make for much better and consistent interfaces across platforms, you can buy in various components to speed things up and support things like copy-n-paste and code in a more structured way.
Another element is skills, if you have the skills to achieve it in a particular technology, then go with that.
To the answer you question the best way I can; you should not use silverlight if you decide to use flash.
HTH
What language, framework, and hosting considerations should one make before starting development of a scalable web application?
The most important consideration is not to over-engineer to the point that it gets in the way of building and launching something. Analysis paralysis is the single biggest inhibitor to productivity, progress and results.
Yes, do some planning. Pick a framework. Perfection in a framework will be impossible to find because it doesn't exist, partially because you don't know what you need until you build it anyways. Chances are, if you pick something, it will be better than picking nothing.
Yes, try to pick flexible, inter-operable tools for where you see yourself going.
Yes, look for a good built-in feature set where you see yourself going in the next 6-18 Months. Trying to look beyond that is not really realistic anyways as most projects change so much anyways going towards the first release.
So, pick what you're comfortable with or what is familiar. Don't follow the crowd, do what gets you the best results, quickest, and often. Understand that you might have to change in the future. So, whatever you build now, try to use unit testing so you can re-factor if ever needed.
If what you're building is going to be super successful, it will be a great problem to have, and an easy one to work on once it's making money as you'll be able to get other talent to help you.
Share what you end up picking and why for your situation -- it helps the us learn from you too!
Don't necessarily marry yourself to one language or framework. It may be that some parts of your site work better with different languages and frameworks than others. For example, all of 37signals' sites are based on Ruby on Rails, but they recently wrote a blog post about how the underlying technology of one is actually written in Erlang now because it's much easier to do concurrency that way.
Obviously there's a level of complexity where things turn into a mishmash, but using the right tool for the job — even if that means different tools for different jobs — can simplify things.
Firstly on language, it largely doesn't matter. PHP, Java and .Net being probably the biggest three are all proven in the sense that they run some of the largest sites on the Web so don't listen to anyone who tells you one is more suited than any of the others.
Some might also put Ruby and Django/Python in this list. I have nothing against them but I'm not aware of any big (say top 50) sites using either.
Hosting considerations depend on how low you want to start but basically the order is:
Shared;
Virtual Private Server;
Dedicated.
Scalability will largely be about your application's design than any language, framework or provider. Efficient database schema, efficient delivery and use of Javascript/CSS and in-memory caching are all issues common to any language or framework.
Language - I'd recommend something with good frameworks and good testing libraries like Perl or Java.
Framework - it depends on what do you plan to do. If you start with a hosting that does not allow FastCGI, it is best to avoid such frameworks like Catalyst or Rails. That's why I love CGI::Application (primarily Perl, but ported to other languages too) - it can run as CGI, FastCGI or mod_perl. For development it can be run from it's own web server.
Hosting - nothing is better than you own server. It can be your own server, leased server or virtual server. But you can start with cheapest hosting and when you need more, you should be able to afford it.
It depends.
Start by looking at your requirements (Functional or user defined) (Non Functional - aspects that describe your desired system link text)
Next I would clarify what it means to have a scalable web application. Define it as test cases that can be clearly tested (must support X page views / second with response time < Y seconds).
Once I had those pieces in place I would look at what type of skills my development team can support (for the intial project and on going maintenance). Then find some case studies of applications out in the wild that use similar language or framework. If someone else has made a specific language / framework scale then chances are good that you can too.
Finally go out and look for some hosting providers that support your chosen language, framework and requirements.
Any suggestions for an accurate Web Log analysis tool to generate reports on the IIS logs? We used WebTrends, but I don't feel it was accurate.
To analyze weblogs, I don't think you can go wrong with Analog: http://www.analog.cx/
If you are analyzing your own logs, which are often huge files, you will want the fastest analyzer you can find. Analog is fast.
You'll want one that's been around awhile and is still supported. Analog just celebrated its 10'th birthday.
Analog claims to be the most popular logfile analyser in the world.
Multi-languages.
Did I say its free and open source?
As far as accuracy goes, no tool gives perfect results. Javascript fails often in catching hits. Trying to track individual people's paths through a website (i.e. for Analytics purposes) is fraught with problems. And even trying to differentiate hits versus visits and screening out the bots is all more of a black art than a science.
What is best is simply to have a tool that gives decent basic statistics that tell you what you need to know.
I've looked at other tools, such as Deep Log Analyzer: http://www.deep-software.com/, which attempts to do analytics from your weblogs. But speed was a problem. They claim their new version 3.5 - April 2008, which I didn't try, has improved performance. The big advantage of a program like this is the advanced reporting you can do, including custom SQL requests. You have to purchase their professional version ($200) to do most of the analytics and custom queries. If Analog is too simple for you, then try the free version of Deep Log Analyzer.
And you can also try Microsoft's own Log Parser, as was the recommended answer in: https://stackoverflow.com/questions/157677/a-good-iis-log-viewer-for-large-log-files.
But you will need some extra skills to use it.
What are you wanting to analyze from your logs? There are a bunch of tools out there - free or paid for - that will go through the logs and spit out a great variety of figures. Some have real meaning, others are best used with a grain of salt.
What none will show you is "How many people are actually reading my wonderful web pages". Those that attempt to show "distinct site visitors" or any detailed metrics are at best a rough approximation to an indication of a vague trend...
But for what it's worth, we use Analog.
SHORT ANSWER:
You are correct to question the results; log analysis is not adequate to report actual traffic.
LONGER ANSWER:
WebTrends is a great tool for what it delivers. But as a previous administrator of a WebTrends installation, I found that web logs are notoriously bad at capturing metrics of interest.
For instance, if there exists any caching in your web delivery stack (or on the consumers side-- *I'm shaking my fist at YOU, AOL!), then your web logs are instantly non-reflective of your site's actual activity. This is because log analysis assumes that all user consumption will translate to an HTTP request back to the web server-- and thus having been recorded in the IIS logs. In the case of a cache, this would not be the case.
In the future if you want more reliable results, you ultimately need to ensure that there exists a way to bust any caching strategy. The obvious answer is dynamic content. But if you do not want to rewrite all of your content in such a fashion, just ensure your web traffic analysis uses a dynamic call.
WebTrends actually offers a solution to this problem, called SDC server. This is exactly what Google Analytics offers as well-- it's a javascript call back to the analysis server.
...I could go for days on this. If you want more specific information, comment back. ;)
EDIT: With WebTrends, specifically, it is quite important to configure session tracking beyond their default IP/userAgent configuration. If your web server assigns a session cookie, you will find this will increase your reliability; especially for differentiating between users which may sit behind the same NAT.
I have had really good luck with SmarterStats, from SmarterTools.
There is a logging package for free from MSFT for viewing this information using SQL Reporting Services. Google it.
doing it with the logs is only a good idea if it's internal - I'd use google analytics for anyhing on teh internets
I have been using Summary, which is paid for software, for years, and love it. The cost of updates is getting to me, and paying for an update to just get user agent string updates out of the deal is getting bothersome. Not that there are not other fixes, I just tend to not need them.
Anyone care to share if they have used Summary compared to analog?
Look at XpoLog log analysis platform for web application servers and web servers log. it a log management and analysis platform that integrate to web servers logs and create reports, provide search and log viewer and also monitor for problems. XpoLog