scalability

问题 This is a very broad question, but hopefully I can get useful tips. Currently I have an ASP.NET application that runs on a single server. I now need to scale out to accommodate increasing customer loads. So my plan is to: 1) Scale out the ASP.NET and web component onto five servers. 2) Move the database onto a farm. I don't believe I will have an issue with the database, as it's just a single IP address as far as the application is concerned. However, I am now concerns about the ASP.NET and

问题 If a collection, like an arraylist, will be storing custom objects (eg Person with several properties) in the thousands, is there anything to do in my code or in the constructor of the collection to prepare it for such a large collection. I'm not really thinking of dedicated threads etc, but more along the lines of the load factor (do I need to touch this for the above scenario?). Thanks 回答1: I'd just initialize the collection to a size that would be close to the final size, in order to

问题 Ok, so the story is like this: -- I am having lots of files (pretty big, around 25GB) that are in a particular format and needs to be imported in a datastore -- these files are continuously updated with data, sometimes new, sometimes the same data -- I am trying to figure out an algorithm on how could I detect if something has changed for a particular line in a file, in order to minimize the time spent updating the database -- the way it currently works now is that I'm dropping all the data

问题 We want to maintain a calendar on our server for each user of an Android app to which the user only has a read-only access. That could lead to our server creating >1000 calendars per day sometimes. If we used a Calendar API like Google's, that would mean creating these many calendars per day from our app's service account. But Google currently restricts the number of calendars created per account to 25 / day and they don't even increase this quota for paid Google Apps accounts (I checked). So

问题 thanks you very much in advance. First of all, I conceive scalability as the ability to design a system that doest not change when the demand of its services, whatever they are, increases considerably. May you need more hardware (vertically or horizontally0? Fine, add it at your leisure because the system is prepared and has been designed to cope with it. My question is simple to ask but presumably very complex to answer. I would like to know what you I look at in a framework to make sure it

问题 I have been learning RavenDB recently and would like to put it to use. I was wondering what advice or suggestions people had around building the system in a way that is ready to scale, specifically sharding the data across servers, but that can start on a single server and only grow as needed. Is it advisable, or even possible, to create multiple databases on a single instance and implement sharding across them. Then to scale it would simply be a matter of spreading these databases across the

问题 I'm new to nodeJS and was wondering about the single-instance model of Node. In a simple nodeJs application, when some blocking operation is asynchronously handled with callbacks, does the main thread running the nodeJs handle the callback as well?. If the request is to get some data off the database, and there are 100s of concurrent users, and each db operation takes couple of seconds, when the callback is finally fired (for each of the connections), is the main thread accepting these

问题 I'm running this scala code on a 32-bit quad-core Core2 system: def job(i:Int,s:Int):Long = { val r=(i to 500000000 by s).map(_.toLong).foldLeft(0L)(_+_) println("Job "+i+" done") r } import scala.actors.Future import scala.actors.Futures._ val JOBS=4 val jobs=(0 until JOBS).toList.map(i=>future {job(i,JOBS)}) println("Running...") val results=jobs.map(f=>f()) println(results.foldLeft(0L)(_+_)) (Yes, I do know there are much more efficient ways to sum a series of integers; it's just to give

问题 Lets say I have multiple devices. Each device has different type of sensors. Now I want to send the data from each device for each sensor to kafka. But I am confused about the kafka topics. For processing this real time data Is it good to have kafka topic per device and all the sensors from that device will send the data to particular kafka topic, or I should create one topic and have all the devices send the data to that one topic. If I go with first case where we will create topic per

问题 There is a major performance issue when using in-object array's as a property versus using a global php array variable, why? To benchmark this problem I created the following benchmark that stores an increasingly larger array with an stdClass as a node, two tests were run one using an array property in a class the other a global array. The test code ini_set('memory_limit', '2250M'); class MyTest { public $storage = []; public function push(){ $this->storage[] = [new stdClass()]; } } echo