I am writing a client-side .NET application which is expected to use a lot of threads. I was warned that .NET performance is very bad when it comes to concurrency. While I am not writing a real-time application, I want to make sure my application is scalable (i.e. allows many threads) and is somehow comparable to an equivalent C++ applic...
I am wondering how it is possible to avoid one socket connection pr. thread in Scala. I have thought a lot about it, but I always end up with some code which is listening for incoming data for each client connection. The problem is that I want to develop an application which should simultanously handle perhaps a couple of thousand conne...
Hi! Here's the deal. We would have taken the complete static html road to solve performance issues, but since the site will be partially dynamic, this won't work out for us. What we have thought of instead is using memcache + eAccelerator to speed up PHP and take care of caching for the most used data. Here's our two approaches that w...
I'm looking into connecting multiple low resolution USB webcams to a single computer. What implications might this have on performance? How does, for example, four 320x240 cameras fare against a single 640x480 camera? I'm not well versed in the architecture of the USB interface, what are the performance caveats? By performance I mean how...
When I first meet PHP, I'm amazed by the idea Sharing-Nothing-Architecture. I once in a project whose scalaiblity suffers from sharing data among different HTTP requests. However, as I proceed my PHP learning. I found that PHP has sessions. This looks conflict with the idea of sharing nothing. So, PHP session is just invented to make...
I was once in a project of web application developed on ASP.NET. For each logon user, there is an object (let's call it UserSessionObject here) created and stored in RAM. For each HTTP request of given user, matching UserSessoinObject instance is used to visit user state information and connection to database. So, this UserSessionObject ...
I'm working on a project with QT and am trying to draw icons from a database. I have auxiliary information in the table that I would like to display if the user chooses to see it (i.e. the x,y of the icon and some other options from database). I am debating on would it be better to go through and just redraw all the icons with this in...
I'm reading about program specialization - specifically java and I don't think I quite understand it to be honest. So far what I understand is that it is a method for optimizing efficiency of programs by constraining parameters or inputs? How is that actually done? Can someone maybe explain to me how it helps, and maybe an example of wha...
I'm trying to find rows which are within __meters from the given point. THis can be done via distance or overlap. WHat is faster? ...
I want to build a Java web app and deploy it on EC2. It will be written in Java and will use MySQL. I was hoping to get some pointers on the actual deployment process and configuration. In particular I'm interested in the following topics: machine images (DIY vs ready made) mysql replication and backup to S3 ways of deploying and redep...
I have read this article from High Scalability about Stack Overflow and other large websites. Many large high traffic .NET sites such as plentyoffish.com, MySpace and Stack Overflow all use .NET technologies and use SQL Server for their database. In the article it says a source in Stack Overflow said: As you add more and more databas...
In order to prevent a SQLite in-memory database from being cleaned up, one must use the same connection to access the database. However, using the same connection causes SQLite to synchronize access to the database. Thus, if I have many threads performing reads against an in-memory database, it is slower on a multi-core machine than the ...
My team and I are in the middle of developing an application which needs to be able to handle pretty heavy traffic. Not facebook level but in the future I would like to be able to scale to that without massive code re-writes. My thought was to modularise out everything into seperate services with their own interfaces. So for example mes...
In my current project (Rails 2.3) we have a collection of 1.2 million keywords, and each of them is associated with a landing page, which is effectively a search results page for a given keywords. Each of those pages is pretty complicated, so it can take a long time to generate (up to 2 seconds with a moderate load, even longer during tr...
I would like to understand database scalability so I've just heard a talk about Habits of Highly Scalable Web Applications http://techportal.ibuildings.com/2010/03/02/habits-of-highly-scalable-web-applications/ On it, the presenter mainly talk about relational database scalability. I also have read something about MapReduce and Column...
I am looking to use MS-Velocity a.k.a Appfabric Cache in a project that is starting by next month (so I am also assuming Q3 will have a go-live license). The project is a web application which will have at least 40K users in 6 months down. And we know for sure that cache server can be of only one node to start with and we will scale hori...
I'm considering using Berkeley DB to cache some data on an application cluster. What's a reasonable upper limit on the number of nodes I can plan on Berkeley DB handling? Writing to the database will be from a single node. ...
I'm reading article about recently release Gizzard sharding framework by twitter(http://engineering.twitter.com/2010/04/introducing-gizzard-framework-for.html). It mentions that all write operations must be idempotent to make sure high reliability. According to wikipedia, "Idempotent operations are operations that can be applied multipl...
I have one small online sale business but I want to make it scalable at limited expense and so am looking out at various services which can help me make my business scalable. I was looking into Amazon Web Services and it seems to be a viable option. Are there any other ways for adding scalability to small online businesses ? ...
I'm building a processing pipeline with NServiceBus but I'm having trouble with the configuration of the distributors in order to make each step in the process scalable. Here's some info: The pipeline will have a master process that says "OK, time to start" for a WorkItem, which will then start a process like a flowchart. Each step in...