scalability

问题 I have seen application to have clustered web server(like 10 to 20 server) to have scalability where they can distribute the load among webservers. But i have always seen all webserver using single DB. Now consider any ecommerce or railways web application where million users are hitting the application at any point of time. To scale at webserver side, we can have server clustering but how we can scale DB ? As we can not have multiple DB like multiple webserver as one dB will have different

问题 I'm new to Azure architecture and am trying to understand why Azure Resource Groups, which are logical deployment buckets for applications built on Azure, are associated with a region when they are defined. At first I thought it was to provide global distribution for disaster recovery or geographic redundancy, but then I realized that a single Resource Group can contain web apps in different regions, which can provide those features via Traffic Manager. I suppose that using separate Resource

问题 Short version If I split my users into shards, how do I offer a "user search"? Obviously, I don't want every search to hit every shard. Long version By shard, I mean have multiple databases where each contains a fraction of the total data. For (a naive) example, the databases UserA, UserB, etc. might contain users whose names begin with "A", "B", etc. When a new user signs up, I simple examine his name and put him into the correct database. When a returning user signs in, I again look at his

问题 I know this has been asked one way or another before, but most of the main issues to do with GAE stability seem to have been asked around the end of 2008, early 2009, or aren't directly related to games at scale (which I'm interested in). Basically, I have been arguing back and forth with my business partner about whether to use GAE or AWS for the back-end of our social game engine, and now it's crunch time. I love GAE (Java) for so many reasons, and although it used to be unstable, it's

问题 I have written a java program that tests the speed of a couple of multi-threading algorithms on different machines with various numbers of processors. On some machines, merge sort* fails because it requires a sizable heap space to work on very large arrays. I can easily change the java heap space myself before running the program, but I feel like a more robust and easy approach would be to do this task from within the program itself. Is there a way to request/achieve more heap space from the

问题 I am trying to understand how can I make Azure Service Bus Topic to be scaleable to handle >10,000 requests/second from more than 50 different clients. I found this article at Microsoft - http://msdn.microsoft.com/en-us/library/windowsazure/hh528527.aspx. This provides lot of good input to scale azure service bus like creating multiple message factories, sending and receiving asynchronously, doing batch send/receive. But all these input are from the publisher and subscriber client perspective

问题 I am looking for information on how to create an ASP.NET web farm - that is, how to make an ASP.NET application (initially designed to work on a single web server) work on 2, 3, 10, etc. servers? We created a web application which works fine when, say, there are 500 users at the same time. But now we need to make it work for 10 000 users (working with the web app at the same time). So we need to set up 20 web servers and make something so that 10 000 users could work with the web app by

问题 I have a website in PHP, Lighttpd. It uses also MySQL on Centos 5. I've tested my PHP with code below with Apache Bench (ab). It resulted in some errors (Failed Requests) indicating other length than normal. I'm absolutely sure that my PHP result should always have the same exact length. I've reviewed my Lighttpd and MySQL logs and error logs and don't have any errors there. Is there any way to check exactly what ab gets when result has other length or is there any other way to find out what

问题 Java based Mahout's goal is to build scalable machine learning libraries. Are there any equivalent libraries in Python ? 回答1: scikits learn is highly recommended http://scikit-learn.sourceforge.net/ 回答2: Spark MLlib is recommmended. It is a scalable machine learning lib, can read data from HDFS and of course runs on top of Spark. You can access it via PySpark (see the Programming Guide's Python examples). 回答3: Orange is supposedly pretty decent, from what I've heard, but I've never used it

问题 I am planning a scalable WordPress based web application but one of the challenges is to make it load quickly in Europe, USA, Canada and Australia. What is the best way to achieve this? I can have web site installed on several servers in several countries and use load balancing? But in such case I would need to sync the databases of all those instances. I think optimal way would be to use Amazon RDS cloud mysql database and I will not need to use several databases and sync them. But now sure