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  • Is node.js ready for production use?

    - by Simon Wentley
    Starting a new project. It's basically a blogging/commenting system. We're considering node.js as the back end server. Is node.js ready for this sort of thing or is it too early and experimental? We need HTTPS and gzip compression - perhaps a front end nginx server could provide this? What's missing from node.js that would make developing a web app difficult? From a production ready perspective, we're wondering if it is stable enough for building a commercial app on top of. Thanks

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  • Install NPM Packages Automatically for Node.js on Windows Azure Web Site

    - by Shaun
    In one of my previous post I described and demonstrated how to use NPM packages in Node.js and Windows Azure Web Site (WAWS). In that post I used NPM command to install packages, and then use Git for Windows to commit my changes and sync them to WAWS git repository. Then WAWS will trigger a new deployment to host my Node.js application. Someone may notice that, a NPM package may contains many files and could be a little bit huge. For example, the “azure” package, which is the Windows Azure SDK for Node.js, is about 6MB. Another popular package “express”, which is a rich MVC framework for Node.js, is about 1MB. When I firstly push my codes to Windows Azure, all of them must be uploaded to the cloud. Is that possible to let Windows Azure download and install these packages for us? In this post, I will introduce how to make WAWS install all required packages for us when deploying.   Let’s Start with Demo Demo is most straightforward. Let’s create a new WAWS and clone it to my local disk. Drag the folder into Git for Windows so that it can help us commit and push. Please refer to this post if you are not familiar with how to use Windows Azure Web Site, Git deployment, git clone and Git for Windows. And then open a command windows and install a package in our code folder. Let’s say I want to install “express”. And then created a new Node.js file named “server.js” and pasted the code as below. 1: var express = require("express"); 2: var app = express(); 3: 4: app.get("/", function(req, res) { 5: res.send("Hello Node.js and Express."); 6: }); 7: 8: console.log("Web application opened."); 9: app.listen(process.env.PORT); If we switch to Git for Windows right now we will find that it detected the changes we made, which includes the “server.js” and all files under “node_modules” folder. What we need to upload should only be our source code, but the huge package files also have to be uploaded as well. Now I will show you how to exclude them and let Windows Azure install the package on the cloud. First we need to add a special file named “.gitignore”. It seems cannot be done directly from the file explorer since this file only contains extension name. So we need to do it from command line. Navigate to the local repository folder and execute the command below to create an empty file named “.gitignore”. If the command windows asked for input just press Enter. 1: echo > .gitignore Now open this file and copy the content below and save. 1: node_modules Now if we switch to Git for Windows we will found that the packages under the “node_modules” were not in the change list. So now if we commit and push, the “express” packages will not be uploaded to Windows Azure. Second, let’s tell Windows Azure which packages it needs to install when deploying. Create another file named “package.json” and copy the content below into that file and save. 1: { 2: "name": "npmdemo", 3: "version": "1.0.0", 4: "dependencies": { 5: "express": "*" 6: } 7: } Now back to Git for Windows, commit our changes and push it to WAWS. Then let’s open the WAWS in developer portal, we will see that there’s a new deployment finished. Click the arrow right side of this deployment we can see how WAWS handle this deployment. Especially we can find WAWS executed NPM. And if we opened the log we can review what command WAWS executed to install the packages and the installation output messages. As you can see WAWS installed “express” for me from the cloud side, so that I don’t need to upload the whole bunch of the package to Azure. Open this website and we can see the result, which proved the “express” had been installed successfully.   What’s Happened Under the Hood Now let’s explain a bit on what the “.gitignore” and “package.json” mean. The “.gitignore” is an ignore configuration file for git repository. All files and folders listed in the “.gitignore” will be skipped from git push. In the example below I copied “node_modules” into this file in my local repository. This means,  do not track and upload all files under the “node_modules” folder. So by using “.gitignore” I skipped all packages from uploading to Windows Azure. “.gitignore” can contain files, folders. It can also contain the files and folders that we do NOT want to ignore. In the next section we will see how to use the un-ignore syntax to make the SQL package included. The “package.json” file is the package definition file for Node.js application. We can define the application name, version, description, author, etc. information in it in JSON format. And we can also put the dependent packages as well, to indicate which packages this Node.js application is needed. In WAWS, name and version is necessary. And when a deployment happened, WAWS will look into this file, find the dependent packages, execute the NPM command to install them one by one. So in the demo above I copied “express” into this file so that WAWS will install it for me automatically. I updated the dependencies section of the “package.json” file manually. But this can be done partially automatically. If we have a valid “package.json” in our local repository, then when we are going to install some packages we can specify “--save” parameter in “npm install” command, so that NPM will help us upgrade the dependencies part. For example, when I wanted to install “azure” package I should execute the command as below. Note that I added “--save” with the command. 1: npm install azure --save Once it finished my “package.json” will be updated automatically. Each dependent packages will be presented here. The JSON key is the package name while the value is the version range. Below is a brief list of the version range format. For more information about the “package.json” please refer here. Format Description Example version Must match the version exactly. "azure": "0.6.7" >=version Must be equal or great than the version. "azure": ">0.6.0" 1.2.x The version number must start with the supplied digits, but any digit may be used in place of the x. "azure": "0.6.x" ~version The version must be at least as high as the range, and it must be less than the next major revision above the range. "azure": "~0.6.7" * Matches any version. "azure": "*" And WAWS will install the proper version of the packages based on what you defined here. The process of WAWS git deployment and NPM installation would be like this.   But Some Packages… As we know, when we specified the dependencies in “package.json” WAWS will download and install them on the cloud. For most of packages it works very well. But there are some special packages may not work. This means, if the package installation needs some special environment restraints it might be failed. For example, the SQL Server Driver for Node.js package needs “node-gyp”, Python and C++ 2010 installed on the target machine during the NPM installation. If we just put the “msnodesql” in “package.json” file and push it to WAWS, the deployment will be failed since there’s no “node-gyp”, Python and C++ 2010 in the WAWS virtual machine. For example, the “server.js” file. 1: var express = require("express"); 2: var app = express(); 3: 4: app.get("/", function(req, res) { 5: res.send("Hello Node.js and Express."); 6: }); 7:  8: var sql = require("msnodesql"); 9: var connectionString = "Driver={SQL Server Native Client 10.0};Server=tcp:tqy4c0isfr.database.windows.net,1433;Database=msteched2012;Uid=shaunxu@tqy4c0isfr;Pwd=P@ssw0rd123;Encrypt=yes;Connection Timeout=30;"; 10: app.get("/sql", function (req, res) { 11: sql.open(connectionString, function (err, conn) { 12: if (err) { 13: console.log(err); 14: res.send(500, "Cannot open connection."); 15: } 16: else { 17: conn.queryRaw("SELECT * FROM [Resource]", function (err, results) { 18: if (err) { 19: console.log(err); 20: res.send(500, "Cannot retrieve records."); 21: } 22: else { 23: res.json(results); 24: } 25: }); 26: } 27: }); 28: }); 29: 30: console.log("Web application opened."); 31: app.listen(process.env.PORT); The “package.json” file. 1: { 2: "name": "npmdemo", 3: "version": "1.0.0", 4: "dependencies": { 5: "express": "*", 6: "msnodesql": "*" 7: } 8: } And it failed to deploy to WAWS. From the NPM log we can see it’s because “msnodesql” cannot be installed on WAWS. The solution is, in “.gitignore” file we should ignore all packages except the “msnodesql”, and upload the package by ourselves. This can be done by use the content as below. We firstly un-ignored the “node_modules” folder. And then we ignored all sub folders but need git to check each sub folders. And then we un-ignore one of the sub folders named “msnodesql” which is the SQL Server Node.js Driver. 1: !node_modules/ 2:  3: node_modules/* 4: !node_modules/msnodesql For more information about the syntax of “.gitignore” please refer to this thread. Now if we go to Git for Windows we will find the “msnodesql” was included in the uncommitted set while “express” was not. I also need remove the dependency of “msnodesql” from “package.json”. Commit and push to WAWS. Now we can see the deployment successfully done. And then we can use the Windows Azure SQL Database from our Node.js application through the “msnodesql” package we uploaded.   Summary In this post I demonstrated how to leverage the deployment process of Windows Azure Web Site to install NPM packages during the publish action. With the “.gitignore” and “package.json” file we can ignore the dependent packages from our Node.js and let Windows Azure Web Site download and install them while deployed. For some special packages that cannot be installed by Windows Azure Web Site, such as “msnodesql”, we can put them into the publish payload as well. With the combination of Windows Azure Web Site, Node.js and NPM it makes even more easy and quick for us to develop and deploy our Node.js application to the cloud.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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  • Where is the node.js file in the stack trace located?

    - by user225189
    Obviously, I'm pretty new to node.js. I'm attempting to debug a node.js application and I see node.js in the stack trace. I would like to put some sys.puts calls in there, but I cannot locate the node.js that is being run by my server. Is there a way to tell where node.js is located? Is there an equivalent to Ruby's FILE in node? Thanks, Brian

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  • Naming selenium grid nodes. Spawning a specific node

    - by ???? ????
    I'm trying to implement a kind of default queues in selenium hub. There is a possibility to specify node's name (actually its environment, smth like "firefox on ubuntu" or "chrome on windows"). Selenium grid itself has a default queue, it works according to 'First In, First Out' principle. But I want to prioritize some of my tasks given to selenium server. I have no possibility to introduce custom queue (seems like there is no API for that), that's why I decided to separate queue's logic from selenium server. I'll only call a specific node with specific name (environment) for example "firefox important node" or smth like that. So, I want to know how to directly tell selenium which node to use for my task? And generally, am I thinking in a right way? Here are my configs: hubConfig.json.erb { "host": null, "port": <%= node[:selenium][:server][:port] %>, "newSessionWaitTimeout": -1, "servlets" : [], "prioritizer": null, "capabilityMatcher": "org.openqa.grid.internal.utils.DefaultCapabilityMatcher", "throwOnCapabilityNotPresent": true, "nodePolling": <%= node[:selenium][:server][:node_polling] %>, "cleanUpCycle": <%= node[:selenium][:server][:cleanup_cycle] %>, "timeout": <%= node[:selenium][:server][:timeout] %>, "browserTimeout": 0, "maxSession": <%= node[:selenium][:server][:max_session] %> } nodeConfig.json.erb { "capabilities": [ { "browserName": "firefox", "maxInstances": 5, "seleniumProtocol": "WebDriver" }, { "browserName": "chrome", "maxInstances": 5, "seleniumProtocol": "WebDriver" }, { "browserName": "phantomjs", "maxInstances": 5, "seleniumProtocol": "WebDriver" } ], "configuration": { "proxy": "org.openqa.grid.selenium.proxy.DefaultRemoteProxy", "maxSession": <%= node[:selenium][:node][:max_session] %>, "port": <%= node[:selenium][:node][:port] %>, "host": "<%= node[:fqdn] %>", "register": true, "registerCycle": <%= node[:selenium][:node][:register_cycle] %>, "hubPort": <%= node[:selenium][:server][:port] %> } } And my Driver class: ... def remote_driver @browser = Watir::Browser.new(:remote, :url => "http://myhub.com:4444/wd/hub", :http_client => client, :desired_capabilities => capabilities ) end def capabilities Selenium::WebDriver::Remote::Capabilities.send( "firefox", :javascript_enabled => true, :css_selectors_enabled => true, :takes_screenshot => true ) end def client client = Selenium::WebDriver::Remote::Http::Default.new client.timeout = 360 client end ... I still don't know how to use specified node for my task. If I try to start a driver adding :name => "firefox important node" and extend nodeConfig.json.erb's configuration with environments: - name: "firefox important node" browser: "*firefox" - name: "Firefox36 on Linux" browser: "*firefox" selenium just starts random firefox browser on a random node. How can I control it?

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  • Microsoft soutient Node.js et participe au développement de la bibliothèque JavaScript client/serveur

    Microsoft soutient Node.js Et participe au développement de la bibliothèque JavaScript client / serveur Sur le blog interoperability Claudio Caldato (Principal Program Manager of Interoperability Srategy Team) annonce que Microsoft va participer au développement d'une version Windows de Node.js Le premier objectif consistera à ajouter à Node une API IOCP Windows performante. Cette phase initiale achevée, un programme exécutable (node.exe) sera disponible sur le site nodejs.org et Node.js fonctionnera alors sur Win...

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  • How to debug node.js applications

    - by Fabian Jakobs
    How do I debug a node.js server application? Right now I'm mostly using alert debugging with print statements like this: sys.puts(sys.inspect(someVariable)); There must be a better way to debug. I know that google Chrome has a command line debugger. Is this debugger available for node.js as well?

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  • Node.js as a custom (streaming) upload handler for Django

    - by Gijs
    I want to build an upload-centric app using Django. One way to do this is with nginx's upload module (nonblocking) but it has its problems. Node.js is supposed to be a good candidate for this type of application. But how can I make node.js act as an upload_handler() for Django (http://docs.djangoproject.com/en/1.1/topics/http/file-uploads/#modifying-upload-handlers-on-the-fly) I'm not sure where to look for examples?

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  • Stream data with Node.js

    - by Saif Bechan
    I want to know if it is possible to stream data from the server to the client with Node.js. From what I can understand all over the internet is that this has to be possible, yet I fail to find a correct example or solution. What I want is a single http post to node.js with AJAX. Than leave the connection open and continuously stream data to the client. The client will receive this stream and update the page continuously.

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  • node.js database

    - by Justin
    I'm looking for a database to pair with a node.js app. I'm assuming a json/nosql db would be preferable to a relational db [I can do without any json/sql impedence mismatch]. Considering couchdb mongodb redis Anyone have any views / war stories re compatiability/deployability of the above with node.js ? Any clear favourites ?

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  • Capture node.js crash reason

    - by dfilkovi
    I have a script written in node.js, it uses 'net' library and communicates with distant service over tcp. This script is started using 'node script.js log.txt' command and everything in that script that is logged using console.log() function gets written to log.txt but sometimes script dies and I cannot find a reason and nothing gets logged in log.txt around the time script crashed. How can I capture crash reason?

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  • using custom CCK fields in node + Drupal 6

    - by artmania
    Hi friends, I'm new at drupal. I created custom content type with CCK. Added some Phone, Address, Fax fields... Now I'm editing the related node. but in the node it just says print $content How can I use the custom fields I've created? maybe something like print $field_name ? anything like that? appreciate helps!!!!!

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  • New MySQL Cluster 7.3 Previews: Foreign Keys, NoSQL Node.js API and Auto-Tuned Clusters

    - by Mat Keep
    At this weeks MySQL Connect conference, Oracle previewed an exciting new wave of developments for MySQL Cluster, further extending its simplicity and flexibility by expanding the range of use-cases, adding new NoSQL options, and automating configuration. What’s new: Development Release 1: MySQL Cluster 7.3 with Foreign Keys Early Access “Labs” Preview: MySQL Cluster NoSQL API for Node.js Early Access “Labs” Preview: MySQL Cluster GUI-Based Auto-Installer In this blog, I'll introduce you to the features being previewed. Review the blogs listed below for more detail on each of the specific features discussed. Save the date!: A live webinar is scheduled for Thursday 25th October at 0900 Pacific Time / 1600UTC where we will discuss each of these enhancements in more detail. Registration will be open soon and published to the MySQL webinars page MySQL Cluster 7.3: Development Release 1 The first MySQL Cluster 7.3 Development Milestone Release (DMR) previews Foreign Keys, bringing powerful new functionality to MySQL Cluster while eliminating development complexity. Foreign Key support has been one of the most requested enhancements to MySQL Cluster – enabling users to simplify their data models and application logic – while extending the range of use-cases for both custom projects requiring referential integrity and packaged applications, such as eCommerce, CRM, CMS, etc. Implementation The Foreign Key functionality is implemented directly within the MySQL Cluster data nodes, allowing any client API accessing the cluster to benefit from them – whether they are SQL or one of the NoSQL interfaces (Memcached, C++, Java, JPA, HTTP/REST or the new Node.js API - discussed later.) The core referential actions defined in the SQL:2003 standard are implemented: CASCADE RESTRICT NO ACTION SET NULL In addition, the MySQL Cluster implementation supports the online adding and dropping of Foreign Keys, ensuring the Cluster continues to serve both read and write requests during the operation.  This represents a further enhancement to MySQL Cluster's support for on0line schema changes, ie adding and dropping indexes, adding columns, etc.  Read this blog for a demonstration of using Foreign Keys with MySQL Cluster.  Getting Started with MySQL Cluster 7.3 DMR1: Users can download either the source or binary and evaluate the MySQL Cluster 7.3 DMR with Foreign Keys now! (Select the Development Release tab). MySQL Cluster NoSQL API for Node.js Node.js is hot! In a little over 3 years, it has become one of the most popular environments for developing next generation web, cloud, mobile and social applications. Bringing JavaScript from the browser to the server, the design goal of Node.js is to build new real-time applications supporting millions of client connections, serviced by a single CPU core. Making it simple to further extend the flexibility and power of Node.js to the database layer, we are previewing the Node.js Javascript API for MySQL Cluster as an Early Access release, available for download now from http://labs.mysql.com/. Select the following build: MySQL-Cluster-NoSQL-Connector-for-Node-js Alternatively, you can clone the project at the MySQL GitHub page.  Implemented as a module for the V8 engine, the new API provides Node.js with a native, asynchronous JavaScript interface that can be used to both query and receive results sets directly from MySQL Cluster, without transformations to SQL. Figure 1: MySQL Cluster NoSQL API for Node.js enables end-to-end JavaScript development Rather than just presenting a simple interface to the database, the Node.js module integrates the MySQL Cluster native API library directly within the web application itself, enabling developers to seamlessly couple their high performance, distributed applications with a high performance, distributed, persistence layer delivering 99.999% availability. The new Node.js API joins a rich array of NoSQL interfaces available for MySQL Cluster. Whichever API is chosen for an application, SQL and NoSQL can be used concurrently across the same data set, providing the ultimate in developer flexibility.  Get started with MySQL Cluster NoSQL API for Node.js tutorial MySQL Cluster GUI-Based Auto-Installer Compatible with both MySQL Cluster 7.2 and 7.3, the Auto-Installer makes it simple for DevOps teams to quickly configure and provision highly optimized MySQL Cluster deployments – whether on-premise or in the cloud. Implemented with a standard HTML GUI and Python-based web server back-end, the Auto-Installer intelligently configures MySQL Cluster based on application requirements and auto-discovered hardware resources Figure 2: Automated Tuning and Configuration of MySQL Cluster Developed by the same engineering team responsible for the MySQL Cluster database, the installer provides standardized configurations that make it simple, quick and easy to build stable and high performance clustered environments. The auto-installer is previewed as an Early Access release, available for download now from http://labs.mysql.com/, by selecting the MySQL-Cluster-Auto-Installer build. You can read more about getting started with the MySQL Cluster auto-installer here. Watch the YouTube video for a demonstration of using the MySQL Cluster auto-installer Getting Started with MySQL Cluster If you are new to MySQL Cluster, the Getting Started guide will walk you through installing an evaluation cluster on a singe host (these guides reflect MySQL Cluster 7.2, but apply equally well to 7.3 and the Early Access previews). Or use the new MySQL Cluster Auto-Installer! Download the Guide to Scaling Web Databases with MySQL Cluster (to learn more about its architecture, design and ideal use-cases). Post any questions to the MySQL Cluster forum where our Engineering team and the MySQL Cluster community will attempt to assist you. Post any bugs you find to the MySQL bug tracking system (select MySQL Cluster from the Category drop-down menu) And if you have any feedback, please post them to the Comments section here or in the blogs referenced in this article. Summary MySQL Cluster 7.2 is the GA, production-ready release of MySQL Cluster. The first Development Release of MySQL Cluster 7.3 and the Early Access previews give you the opportunity to preview and evaluate future developments in the MySQL Cluster database, and we are very excited to be able to share that with you. Let us know how you get along with MySQL Cluster 7.3, and other features that you want to see in future releases, by using the comments of this blog.

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  • How to manage different form contexts of same form element in single DOM tree

    - by nimp
    Hi, As my question title could be bit unclear to you (I tried best), following is what I'm exactly trying to do. I'm having a form element (say a user_info form), where such form elements will be generated for different users by java script and displayed in different js tabs (example: dojo tabs). once form elements are generated, later I need to react on user actions performed on different html elements defined inside user_info form. In this case I need to identify what is the context (in which user_info form element) in which user is working on. The simplest example would be how to retrieve form id of the form in which user actions are being performed. According to my understanding, I can not simply retrieve from by form id, because now DOM tree contains duplicate form instances of the same from element. So, IS there anyway, I could identify form context based on the user actions on its input elements. Thank You.

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  • Node.js running under IIS Express Keeps Crashing

    - by PazoozaTest Pazman
    I recently resinstalled Windows 7 on my machine and went back to downloading and installing the tools to help me continue developing node.js windows azure web applications. I followed the instructions given on the node.js azure site: http://www.windowsazure.com/en-us/develop/nodejs/ and using web installer 4.0 it says I have successfully installed these tools: Windows Azure Powershell Windows Azure SDK for Node.js - June 2012 Windows Azure SDK for .Net (VS 2012 RC) - June 2012 IIS Recommend Configuration The problem I am experiencing is that when I run the site using powershell e.g: start-azureemulator -launch it goes ahead and runs IIS Express, and after several minutes IIS Express crashes with the following information: Problem signature: Problem Event Name: APPCRASH Application Name: iisexpress.exe Application Version: 8.0.8298.0 Application Timestamp: 4f620349 Fault Module Name: iiscore.dll Fault Module Version: 8.0.8298.0 Fault Module Timestamp: 4f63b65c Exception Code: c0000005 Exception Offset: 00021767 OS Version: 6.1.7601.2.1.0.256.28 Locale ID: 1033 Additional Information 1: f66d Additional Information 2: f66d807b515d6b2dc6f28f66db769a01 Additional Information 3: 7b2f Additional Information 4: 7b2f6797d07ebc2c23f2b227e779722e I am running 2 instances each time, and both of them crash one after the other. Is anyone experiencing something similar and fix this issue ? Is their an upgrade I need to do ? I've run windows update but it says I've got all the latest updates etc. Can I tell the powershell cmdlet to use IIS 7 instead of IIS Express? I'm guessing its something to do with IIS Express on my machine. I did some hunting around and found this person here who experienced a similar problem: https://github.com/tjanczuk/iisnode/issues/149 I've got a cron job running every 1 second, to check if any website totals need to be updated. Could this be causing IIS Express to crash? Cheers

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  • Running mysql query using node blocks the whole process and then timesout

    - by lobengula3rd
    I have a node javascript that uses mysql npm (Felix). I have a procedure stored in my DB which I call when the user selects an option to kind of create its own instance of the program. The user chooses for how long he wants that data to be initialized for him. This is suppsoed to be between 1 and 2 years. So if he choose 1 year this query will insert around 20,000 rows into 1 table. If I run this query and a local DB this takes around 30 seconds (I suppose it is reasonable because its a big query which should be done only once in 1 or 2 years so its ok). For some reason my node script freezes as if it can't handle any more calls from other users. The even worse problem is that after like 2 minutes my client ui gets like an error from the server. At this point not all the data that was supposed to enter the DB is entered. After waiting like another minute all the data finally gets to the DB and only then it will accept new requests. This is my connection: this.connection = mysql.createConnection({ host : '********rds.amazonaws.com', user : 'admin', password : '******', database : '*****' }); and this is my query function: this.createCourts = function (req, res, next){ connection.query('CALL filldates("' + req.body['startDate'] + '","' + req.body['endDate'] + '","' + req.body['numOfCourts'] + '","' + req.body['duration'] + '","' + req.body['sundayOpen'] + '","' + req.body['mondayOpen'] + '","' + req.body['tuesdayOpen'] + '","' + req.body['wednesdayOpen'] + '","' + req.body['thursdayOpen'] + '","' + req.body['fridayOpen'] + '","' + req.body['saturdayOpen'] + '","' + req.body['sundayClose'] + '","' + req.body['mondayClose'] + '","' + req.body['tuesdayClose'] + '","' + req.body['wednesdayClose'] + '","' + req.body['thursdayClose'] + '","' + req.body['fridayClose'] + '","' + req.body['saturdayClose'] + '");', function(err){ if (err){ console.log(err); } else return res.send(200); }); }; what am i missing here? as i understand connection.query should by async so why is it actually blocking my node script? thanks.

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  • Node & Redis: Crucial Design Issues in Production Mode

    - by Ali
    This question is a hybrid one, being both technical and system design related. I'm developing the backend of an application that will handle approx. 4K request per second. We are using Node.js being super fast and in terms of our database struction we are using MongoDB, with Redis being a layer between Node and MongoDB handling volatile operations. I'm quite stressed because we are expecting concurrent requests that we need to handle carefully and we are quite close to launch. However I do not believe I've applied the correct approach on redis. I have a class Student, and they constantly change stages(such as 'active', 'doing homework','in lesson' etc. Thus I created a Redis DB for each state. (1 for being 'active', 2 for being 'doing homework'). Above I have the structure of the 'active' students table; xa5p - JSON stringified object #1 pQrW - JSON stringified object #2 active_student_table - {{studentId:'xa5p'}, {studentId:'pQrW'}} Since there is no 'select all keys method' in Redis, I've been suggested to use a set such that when I run command 'smembers' I receive the keys and later on do 'get' for each id in order to find a specific user (lets say that age older than 15). I've been also suggested that in fact I used never use keys in production mode. My question is, no matter how 'conceptual' it is, what specific things I should avoid doing in Node & Redis in production stage?. Are they any issues related to my design? Students must be objects and I sure can list them in a list but I haven't done yet. Is it that crucial in production stage?

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  • Can't get node.js built on cygwin

    - by mwt
    Following the instructions here: https://github.com/ry/node/wiki/Building-node.js-on-Cygwin-(Windows) I've tried installing on two machines, either of which I'd be happy to get up and running. WinXP On 'make', I get: Build failed: -> task failed <err #2>: {task: libv8.a SConstruct -> libv8.a} According to the instructions, this is caused by having $SHELL set to a Windows style path, but I've set it to /bin/bash and get the same error. Win7 On './configure', I get: $ ./configure Checking for program g++ or c++ : /usr/bin/g++ Checking for program cpp : /usr/bin/cpp Checking for program ar : /usr/bin/ar Checking for program ranlib : /usr/bin/ranlib Checking for g++ : ok Checking for program gcc or cc : /usr/bin/gcc 0 [main] python 1092 C:\bin\python.exe: *** fatal error - unable to remap \\?\C:\lib\python2.6\lib-dynload\_functools.dll to same address as parent: 0x360000 != 0x3E0000 Stack trace: Frame Function Args 002891E8 6102749B (002891E8, 00000000, 00000000, 00000000) 002894D8 6102749B (61177B80, 00008000, 00000000, 61179977) 0028A508 61004AFB (611A136C, 61241CF4, 00360000, 003E0000) End of stack trace 0 [main] python 3536 fork: child 1092 - died waiting for dll loading, errno 11 /Users/Michael/Desktop/node/wscript:177: error: could not configure a c compiler! I've run 'rebaseall' and restarted the machine but still get that error. Edit: Ok, rebaseall was apparently erroring on some mingw stuff, so I edited the rebaseall script to fix that, and now it configures on Win7. The new problem is that it emits the exact same error as my XP machine now when I try to make. This is on tag v0.3.5.

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  • Power Distribution amongst connected nodes

    - by Perky
    In my game the map is represented by connected nodes, each node has a number of connected nodes. The nodes represent a system in which players can build structures and move units about. If you're familiar with Sins of a Solar Empire the game map is very similar. I want each node to be able to produce power and share it with all connected nodes. For example if A, B, C & D are all connected and produce 100 power units, then each system should have 400 power units available. If node B builds a structure that consumes 100 power units then A, B, C & D should then have 300 power units available. I've been working on this system all day and haven't been able to get it working quite the way I want. My current implementation is to first recurse through each nodes's connected node adding up the power, I keep a list of closed nodes so it doesn't loop, it's quite similar to A* actually. Pseudo code: All nodes start with the properties node.power = 0 node.basePower = 100 // could be different for each node. node.initialPower = node.basePower - function propagatePower( node, initialPower, closedNodes ) node.power += initialPower add( closedNodes, node ) connectedNodes = connected_nodes_except_from( closedNodes ) foreach node in connectedNodes do propagatePower( node, initialPower, closedNodes ) end end After this I iterate through all power consumers. foreach consumer in consumers do node = consumer.parentNode if node.power >= consumer.powerConsumption then consumer.powerConsumed += consumer.powerConsumption node.producedPower -= consumer.powerConsumption end end Then I adjust the initial power for the next propagation cycle. foreach node in nodes do node.initialPower = node.basePower - node.producedPower node.displayPower = node.power // for rendering the power. node.power = 0 end This seemed to work at first but then I came into a problem. Say two nodes A & B produce 100Pu each, it's shared so both A & B have 200Pu. I then make two structures that consume 80Pu each on A (160Pu). Then the nodes power is adjusted to basePower - producedPower (100-160 = -60). Nodes are propagated, both nodes now have 40Pu (A: -60 + B: 100 = 40). Which is correct because they started with 200Pu - 160Pu = 40Pu. However now node.power >= consumer.powerConsumption is false. Whats worse is it's false for any structure that uses more that 40Pu, so the whole system goes down. I could deduct from consumer.powerConsumption but what do I do if power is reduced elsewhere? I don't have the correct data to perform the necessary checks. It's late so I'm probably not thinking straight but I thought to ask on here to see if anyone has any other implementations, better or worse I'd be interested to know.

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  • Link List Problem,

    - by david
    OK i have a problem with a Link List program i'm trying to Do, the link List is working fine. Here is my code #include <iostream> using namespace std; struct record { string word; struct record * link; }; typedef struct record node; node * insert_Node( node * head, node * previous, string key ); node * search( node *head, string key, int *found); void displayList(node *head); node * delete_node( node *head, node * previous, string key); int main() { node * previous, * head = NULL; int found = 0; string node1Data,newNodeData, nextData,lastData; //set up first node cout <<"Depature"<<endl; cin >>node1Data; previous = search( head, node1Data, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, node1Data); cout <<"Depature inserted"<<endl; //insert node between first node and head cout <<"Destination"<<endl; cin >>newNodeData; previous = search( head, newNodeData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, newNodeData); cout <<"Destinationinserted"<<endl; //insert node between second node and head cout <<"Cost"<<endl; cin >>newNodeData; previous = search( head, newNodeData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, newNodeData); cout <<"Cost inserted"<<endl; cout <<"Number of Seats Required"<<endl; //place node between new node and first node cin >>nextData; previous = search( head, nextData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, nextData); cout <<"Number of Seats Required inserted"<<endl; //insert node between first node and head cout <<"Name"<<endl; cin >>newNodeData; previous = search( head, newNodeData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, newNodeData); cout <<"Name inserted"<<endl; //insert node between node and head cout <<"Address "<<endl; cin >>newNodeData; previous = search( head, newNodeData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, newNodeData); cout <<"Address inserted"<<endl; //place node as very last node cin >>lastData; previous = search( head, lastData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, lastData); cout <<"C"<<endl; displayList(head); char Ans = 'y'; //Delete nodes do { cout <<"Enter Keyword to be delete"<<endl; cin >>nextData; previous = search( head, nextData, &found); if (found == 1) head = delete_node( head, previous,nextData); displayList(head); cout <<"Do you want to Delete more y /n "<<endl; cin >> Ans; } while( Ans =='y'); int choice, i=0, counter=0; int fclass[10]; int coach[10]; printf("Welcome to the booking program"); printf("\n-----------------"); do{ printf("\n Please pick one of the following option:"); printf("\n 1) Reserve a first class seat on Flight 101."); printf("\n 2) Reserve a coach seat on Flight 101."); printf("\n 3) Quit "); printf("\n ---------------------------------------------------------------------"); printf("\nYour choice?"); scanf("%d",&choice); switch(choice) { case 1: i++; if (i <10){ printf("Here is your seat: %d " , fclass[i]); } else if (i = 10) { printf("Sorry there is no more seats on First Class. Please wait for the next flight"); } break; case 2: if (i <10){ printf("Here is your Seat Coach: %d " , coach[i]); } else if ( i = 10) { printf("Sorry their is no more Seats on Coach. Please wait for the next flight"); } break; case 3: printf("Thank you and goodbye\n"); //exit(0); } } while (choice != 3); } /******************************************************* search function to return previous position of node ******************************************************/ node * search( node *head, string key, int *found) { node * previous, * current; current = head; previous = current; *found = 0;//not found //if (current->word < key) move through links until the next link //matches or current_word > key while( current !=NULL) { //compare exactly if (key ==current->word ) { *found = 1; break; } //if key is less than word else if ( key < current->word ) break; else { //previous stays one link behind current previous = current; current = previous -> link; } } return previous; } /******************************************************** display function as used with createList ******************************************************/ void displayList(node *head) { node * current; //current now contains the address held of the 1st node similar //to head current = head; cout << "\n\n"; if( current ==NULL) cout << "Empty List\n\n"; else { /*Keep going displaying the contents of the list and set current to the address of the next node. When set to null, there are no more nodes */ while(current !=NULL) { cout << current->word<<endl; current = current ->link; } } } /************************************************************ insert node used to position node (i) empty list head = NULL (ii) to position node before the first node key < head->word (iii) every other position including the end of the list This is done using the following steps (a) Pass in all the details to create the node either details or a whole record (b) Pass the details over to fill the node (C) Use the if statement to add the node to the list **********************************************************/ node * insert_Node( node * head, node * previous, string key ) { node * new_node, * temp; new_node = new node; //create the node new_node ->word = key; new_node -> link = NULL; if (head == NULL || key < head->word ) //empty list { //give address of head to temp temp = head; //head now points to the new_node head = new_node; //new_node now points to what head was pointing at new_node -> link = temp; } else { //pass address held in link to temp temp = previous-> link; //put address of new node to link of previous previous -> link = new_node; //pass address of temp to link of new node new_node -> link = temp; } return head; } node * delete_node( node *head, node * previous, string key) { /* this function will delete a node but will not return its contents */ node * temp; if(key == head->word) //delete node at head of list { temp = head; //point head at the next node head = head -> link; } else { //holds the address of the node after the one // to be deleted temp = previous-> link; /*assign the previous to the address of the present node to be deleted which holds the address of the next node */ previous-> link = previous-> link-> link; } delete temp; return head; }//end delete The problem i have is when i Enter in the Number 2 in the Node(Seats) i like to get a Counter Taken 2 off of 50, some thing like what i have here enter code here int choice, i=0, counter=0; int fclass[10]; int coach[10]; printf("Welcome to the booking program"); printf("\n-----------------"); do{ printf("\n Please pick one of the following option:"); printf("\n 1) Reserve a first class seat on Flight 101."); printf("\n 2) Reserve a coach seat on Flight 101."); printf("\n 3) Quit "); printf("\n ---------------------------------------------------------------------"); printf("\nYour choice?"); scanf("%d",&choice); switch(choice) { case 1: i++; if (i <10){ printf("Here is your seat: %d " , fclass[i]); } else if (i = 10) { printf("Sorry there is no more seats on First Class. Please wait for the next flight"); } break; case 2: if (i <10){ printf("Here is your Seat Coach: %d " , coach[i]); } else if ( i = 10) { printf("Sorry their is no more Seats on Coach. Please wait for the next flight"); } break; case 3: printf("Thank you and goodbye\n"); //exit(0); } } while (choice != 3); How can i get what the User enters into number of Seats into this function

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  • ZF: Form array field - how to display values in the view correctly

    - by Wojciech Fracz
    Let's say I have a Zend_Form form that has a few text fields, e.g: $form = new Zend_Form(); $form->addElement('text', 'name', array( 'required' => true, 'isArray' => true, 'filters' => array( /* ... */ ), 'validators' => array( /* ... */ ), )); $form->addElement('text', 'surname', array( 'required' => true, 'isArray' => true, 'filters' => array( /* ... */ ), 'validators' => array( /* ... */ ), )); After rendering it I have following HTML markup (simplified): <div id="people"> <div class="person"> <input type="text" name="name[]" /> <input type="text" name="surname[]" /> </div> </div> Now I want to have the ability to add as many people as I want. I create a "+" button that in Javascript appends next div.person to the container. Before I submit the form, I have for example 5 names and 5 surnames, posted to the server as arrays. Everything is fine unless somebody puts the value in the field that does not validate. Then the whole form validation fails and when I want to display the form again (with errors) I see the PHP Warning: htmlspecialchars() expects parameter 1 to be string, array given Which is more or less described in ticket: http://framework.zend.com/issues/browse/ZF-8112 However, I came up with a not-very-elegant solution. What I wanted to achieve: have all fields and values rendered again in the view have error messages only next to the fields that contained bad values Here is my solution (view script): <div id="people"> <?php $names = $form->name->getValue(); // will have an array here if the form were submitted $surnames= $form->surname->getValue(); // only if the form were submitted we need to validate fields' values // and display errors next to them; otherwise when user enter the page // and render the form for the first time - he would see Required validator // errors $needsValidation = is_array($names) || is_array($surnames); // print empty fields when the form is displayed the first time if(!is_array($names))$names= array(''); if(!is_array($surnames))$surnames= array(''); // display all fields! foreach($names as $index => $name): $surname = $surnames[$index]; // validate value if needed if($needsValidation){ $form->name->isValid($name); $form->surname->isValid($surname); } ?> <div class="person"> <?=$form->name->setValue($name); // display field with error if did not pass the validation ?> <?=$form->surname->setValue($surname);?> </div> <?php endforeach; ?> </div> The code work, but I want to know if there is an appropriate, more comfortable way to do this? I often hit this problem when there is a need for a more dynamic - multivalue forms and have not find better solution for a long time.

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  • Using a C#.net DLL in Node.js / serverside javascript

    - by Dve
    I have spent a while playing with node.js and exploring related frameworks such as express and geddy... and I am very impressed, especially with the WebSockets implementation in socket.io. I have a pet project that is an online game, the entire game engine is written in C# and I would like to know if there is anyway I can call the functions of this existing dll from a solution built using node.js, socket.io, express etc? The game engine itself is pretty complete; tested and robust. I am hoping there is some neat way of exposing its functionality without to much overhead. Thanks

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