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  • (Rails) Assert_Select's Annoying Warnings

    - by CalebHC
    Does anyone know how to make assert_select not output all those nasty html warnings during a rake test? You know, like this stuff: .ignoring attempt to close body with div opened at byte 1036, line 5 closed at byte 5342, line 42 attributes at open: {"class"=>"inner02"} text around open: "</script>\r\t</head>\r\t<body class=\"inner02" text around close: "\t</div>\r\t\t\t</div>\r\t\t</div>\r\t</body>\r</ht" Thanks

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  • Annotate gem and rails 3.1

    - by vincent jacquel
    Does anyone have any idea why annotate does not work anymore in rails 3.1 ? When trying to run it with : $ rvmsudo bundle exec annotate --position before and given I've got the following in my gemfile: gem "annotate", '2.4.0' I get the following error: /usr/local/rvm/gems/ruby-1.9.2-p180@rails31/gems/activerecord-3.1.0/lib/active_record /railties/databases.rake:3:in `<top (required)>': undefined method `namespace' for main:Object (NoMethodError) I'm using RVM with a gemset dedicated to rails 3.1 with Ruby 1.9.2

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  • About to migrate :string but I'm thinking :text might be better. Performance/Purpose?

    - by Sam
    class CreateScrapes < ActiveRecord::Migration def self.up create_table :scrapes do |t| t.text :saved_characters t.text :sanitized_characters t.string :href t.timestamps end end def self.down drop_table :scrapes end end I'm about to rake db:migrate and I'm think about the attribute type if I should be using text or string. Since saved_characters and sanitized_characters will be arrays with thousands of unicode values, its basically comma delimited data, I'm not sure if `:text' is really the right way to go here. What would you do?

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  • How do I set up a route in rails?

    - by NotDan
    In my routes.rb I have this: map.namespace :admin do |admin| admin.resources :galleries do |galleries| galleries.resources :gallery_images, :as=>'images' end end rake routes shows the route created like this: admin_gallery GET /admin/galleries/:id and when I go to this url in my browser: http://192.168.2.2:3000/admin/galleries/11/ I get this error: Unknown action No action responded to 11 But I would have expected it to use the show action/view, what am I doing wrong?

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  • Help installing delayed_job

    - by Mike
    I'm trying to use collectiveidea's delayed_job gem The installation instructions include Rake tasks are not automatically loaded from gems, so you’ll need to add the following to your Rakefile: begin require 'delayed/tasks' rescue LoadError STDERR.puts "Run `rake gems:install` to install delayed_job" end Where is my Rakefile? And what is a Rakefile?

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  • rails db:seed no method error

    - by louddwarf
    when I try and run the "rake db:seed" command the rails console outputs "NoMethodError: undefined method `db' for #" not quite sure what going on. I'm using netbeans to build my rails project which is using the built-in JRuby 1.2 would that have anything to do with it?

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  • How to create a project template for Ruby on Rails projects?

    - by wgpubs
    When I build Rails applications I find myself doing the same things over and over again. This includes adding the same gems/plugins, configuration info and custom initializers, rake tasks etc... etc.... This can't be a good thing. So, is there a way to package all this repetitive code into some sort of project template ... so that I can do a "rails myapp" and have everything good to go from there? Btw, running 2.3.5 if that matters :) thanks

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  • Nested Resource - How to pass needed keys, and attribute to update?

    - by Jason B
    My nested resources are working for form_for updates, but I have a few toggles that I need to setup to change a status field. So I am using link_to, and accessing the url helper. link_to "toggle", edit_project_expense_path(@project[:id],expense_item[:id]) routes.rb resources :projects do resources :expenses end match '/submit_expense/:id' => 'expenses#submit_expense', :as => 'submit_expense' rake routes edit_project_expense GET /projects/:project_id/expenses/:id/edit(.:format) expenses#edit My question is: How can I also send along :approval_status = "1", with my link_to?

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  • Using Git or Mercurial, how would you know when you do a clone or a pull, no one is checking in file

    - by Jian Lin
    Using Git or Mercurial, how would you know when you do a clone or a pull, no one is checking in files (pushing it)? It can be important that: 1) You never know it is in an inconsistent state, so you try for 2 hours trying to debug the code for what's wrong. 2) With all the framework code -- potentially hundreds of files -- if some files are inconsistent with the other, can't the rake db:migrate or script/generate controller cause some damage or inconsistencies to the code base?

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  • MIgrations and Rspec

    - by pablorc
    Hi, I'm developing a Rails application with Rspec for unit testing. Weeks ago, Rspec used to migrate the database to the last version automatically when executing 'rake spec', but now it doesn't do it automatically, I have to implement everything for myself. This happens in test environment, because my development data doesn't desappear. Is my fault? I didn't change anything, I think :) Thanks in advance.

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  • Where is my app.config for SSIS?

    Sometimes when working with SSIS you need to add or change settings in the .NET application configuration file, which can be a bit confusing when you are building a SSIS package not an application. First of all lets review a couple of examples where you may need to do this. You are using referencing an assembly in a Script Task that uses Enterprise Library (aka EntLib), so you need to add the relevant configuration sections and settings, perhaps for the logging application block. You are using using Enterprise Library in a custom task or component, and again you need to add the relevant configuration sections and settings. You are using a web service with Microsoft Web Services Enhancements (WSE) 3.0 and hosting the proxy in SSIS, in an assembly used by your package, and need to add the configuration sections and settings. You need to change behaviours of the .NET framework which can be influenced by a configuration file, such as the System.Net.Mail default SMTP settings. Perhaps you wish to configure System.Net and the httpWebRequest header for parsing unsafe header (useUnsafeHeaderParsing), which will change the way the HTTP Connection manager behaves. You are consuming a WCF service and wish to specify the endpoint in configuration. There are no doubt plenty more examples but each of these requires us to identify the correct configuration file and and make the relevant changes. There are actually several configuration files, each used by a different execution host depending on how you are working with the SSIS package. The folders we need to look in will actually vary depending on the version of SQL Server as well as the processor architecture, but most are all what we can call the Binn folder. The SQL Server 2005 Binn folder is at C:\Program Files\Microsoft SQL Server\90\DTS\Binn\, compared to C:\Program Files\Microsoft SQL Server\100\DTS\Binn\ for SQL Server 2008. If you are on a 64-bit machine then you will see C:\Program Files (x86)\Microsoft SQL Server\90\DTS\Binn\ for the 32-bit executables and C:\Program Files\Microsoft SQL Server\90\DTS\Binn\ for 64-bit, so be sure to check all relevant locations. Of course SQL Server 2008 may have a C:\Program Files (x86)\Microsoft SQL Server\100\DTS\Binn\ on a 64-bit machine too. To recap, the version of SQL Server determines if you look in the 90 or 100 sub-folder under SQL Server in Program Files (C:\Program Files\Microsoft SQL Server\nn\) . If you are running a 64-bit operating system then you will have two instances program files, C:\Program Files (x86)\ for 32-bit and  C:\Program Files\ for 64-bit. You may wish to check both depending on what you are doing, but this is covered more under each section below. There are a total of five specific configuration files that you may need to change, each one is detailed below: DTExec.exe.config DTExec.exe is the standalone command line tool used for executing SSIS packages, and therefore it is an execution host with an app.config file. e.g. C:\Program Files\Microsoft SQL Server\90\DTS\Binn\DTExec.exe.config The file can be found in both the 32-bit and 64-bit Binn folders. DtsDebugHost.exe.config DtsDebugHost.exe is the execution host used by Business Intelligence Development Studio (BIDS) / Visual Studio when executing a package from the designer in debug mode, which is the default behaviour. e.g. C:\Program Files\Microsoft SQL Server\90\DTS\Binn\DtsDebugHost.exe.config The file can be found in both the 32-bit and 64-bit Binn folders. This may surprise some people as Visual Studio is only 32-bit, but thankfully the debugger supports both. This can be set in the project properties, see the Run64BitRuntime property (true or false) in the Debugging pane of the Project Properties. dtshost.exe.config dtshost.exe is the execution host used by what I think of as the built-in features of SQL Server such as SQL Server Agent e.g. C:\Program Files\Microsoft SQL Server\90\DTS\Binn\dtshost.exe.config This file can be found in both the 32-bit and 64-bit Binn folders devenv.exe.config Something slightly different is devenv.exe which is Visual Studio. This configuration file may also need changing if you need a feature at design-time such as in a Task Editor or Connection Manager editor. Visual Studio 2005 for SQL Server 2005  - C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\devenv.exe.config Visual Studio 2008 for SQL Server 2008  - C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE\devenv.exe.config Visual Studio is only available for 32-bit so on a 64-bit machine you will have to look in C:\Program Files (x86)\ only. DTExecUI.exe.config The DTExec UI tool can also have a configuration file and these cab be found under the Tools folders for SQL Sever as shown below. C:\Program Files\Microsoft SQL Server\90\Tools\Binn\VSShell\Common7\IDE\DTExecUI.exe C:\Program Files\Microsoft SQL Server\100\Tools\Binn\VSShell\Common7\IDE\DTExecUI.exe A configuration file may not exist, but if you can find the matching executable you know you are in the right place so can go ahead and add a new file yourself. In summary we have covered the assembly configuration files for all of the standard methods of building and running a SSIS package, but obviously if you are working programmatically you will need to make the relevant modifications to your program’s app.config as well.

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  • SQL SERVER – Signal Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28

    - by pinaldave
    In this post, let’s delve a bit more in depth regarding wait stats. The very first question: when do the wait stats occur? Here is the simple answer. When SQL Server is executing any task, and if for any reason it has to wait for resources to execute the task, this wait is recorded by SQL Server with the reason for the delay. Later on we can analyze these wait stats to understand the reason the task was delayed and maybe we can eliminate the wait for SQL Server. It is not always possible to remove the wait type 100%, but there are few suggestions that can help. Before we continue learning about wait types and wait stats, we need to understand three important milestones of the query life-cycle. Running - a query which is being executed on a CPU is called a running query. This query is responsible for CPU time. Runnable – a query which is ready to execute and waiting for its turn to run is called a runnable query. This query is responsible for Signal Wait time. (In other words, the query is ready to run but CPU is servicing another query). Suspended – a query which is waiting due to any reason (to know the reason, we are learning wait stats) to be converted to runnable is suspended query. This query is responsible for wait time. (In other words, this is the time we are trying to reduce). In simple words, query execution time is a summation of the query Executing CPU Time (Running) + Query Wait Time (Suspended) + Query Signal Wait Time (Runnable). Again, it may be possible a query goes to all these stats multiple times. Let us try to understand the whole thing with a simple analogy of a taxi and a passenger. Two friends, Tom and Danny, go to the mall together. When they leave the mall, they decide to take a taxi. Tom and Danny both stand in the line waiting for their turn to get into the taxi. This is the Signal Wait Time as they are ready to get into the taxi but the taxis are currently serving other customer and they have to wait for their turn. In other word they are in a runnable state. Now when it is their turn to get into the taxi, the taxi driver informs them he does not take credit cards and only cash is accepted. Neither Tom nor Danny have enough cash, they both cannot get into the vehicle. Tom waits outside in the queue and Danny goes to ATM to fetch the cash. During this time the taxi cannot wait, they have to let other passengers get into the taxi. As Tom and Danny both are outside in the queue, this is the Query Wait Time and they are in the suspended state. They cannot do anything till they get the cash. Once Danny gets the cash, they are both standing in the line again, creating one more Signal Wait Time. This time when their turn comes they can pay the taxi driver in cash and reach their destination. The time taken for the taxi to get from the mall to the destination is running time (CPU time) and the taxi is running. I hope this analogy is bit clear with the wait stats. You can check the Signalwait stats using following query of Glenn Berry. -- Signal Waits for instance SELECT CAST(100.0 * SUM(signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%signal (cpu) waits], CAST(100.0 * SUM(wait_time_ms - signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%resource waits] FROM sys.dm_os_wait_stats OPTION (RECOMPILE); Higher the Signal wait stats are not good for the system. Very high value indicates CPU pressure. In my experience, when systems are running smooth and without any glitch the Signal wait stat is lower than 20%. Again, this number can be debated (and it is from my experience and is not documented anywhere). In other words, lower is better and higher is not good for the system. In future articles we will discuss in detail the various wait types and wait stats and their resolution. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL DMV, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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  • SQL SERVER – Single Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28

    - by pinaldave
    In this post, let’s delve a bit more in depth regarding wait stats. The very first question: when do the wait stats occur? Here is the simple answer. When SQL Server is executing any task, and if for any reason it has to wait for resources to execute the task, this wait is recorded by SQL Server with the reason for the delay. Later on we can analyze these wait stats to understand the reason the task was delayed and maybe we can eliminate the wait for SQL Server. It is not always possible to remove the wait type 100%, but there are few suggestions that can help. Before we continue learning about wait types and wait stats, we need to understand three important milestones of the query life-cycle. Running - a query which is being executed on a CPU is called a running query. This query is responsible for CPU time. Runnable – a query which is ready to execute and waiting for its turn to run is called a runnable query. This query is responsible for Single Wait time. (In other words, the query is ready to run but CPU is servicing another query). Suspended – a query which is waiting due to any reason (to know the reason, we are learning wait stats) to be converted to runnable is suspended query. This query is responsible for wait time. (In other words, this is the time we are trying to reduce). In simple words, query execution time is a summation of the query Executing CPU Time (Running) + Query Wait Time (Suspended) + Query Single Wait Time (Runnable). Again, it may be possible a query goes to all these stats multiple times. Let us try to understand the whole thing with a simple analogy of a taxi and a passenger. Two friends, Tom and Danny, go to the mall together. When they leave the mall, they decide to take a taxi. Tom and Danny both stand in the line waiting for their turn to get into the taxi. This is the Signal Wait Time as they are ready to get into the taxi but the taxis are currently serving other customer and they have to wait for their turn. In other word they are in a runnable state. Now when it is their turn to get into the taxi, the taxi driver informs them he does not take credit cards and only cash is accepted. Neither Tom nor Danny have enough cash, they both cannot get into the vehicle. Tom waits outside in the queue and Danny goes to ATM to fetch the cash. During this time the taxi cannot wait, they have to let other passengers get into the taxi. As Tom and Danny both are outside in the queue, this is the Query Wait Time and they are in the suspended state. They cannot do anything till they get the cash. Once Danny gets the cash, they are both standing in the line again, creating one more Single Wait Time. This time when their turn comes they can pay the taxi driver in cash and reach their destination. The time taken for the taxi to get from the mall to the destination is running time (CPU time) and the taxi is running. I hope this analogy is bit clear with the wait stats. You can check the single wait stats using following query of Glenn Berry. -- Signal Waits for instance SELECT CAST(100.0 * SUM(signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%signal (cpu) waits], CAST(100.0 * SUM(wait_time_ms - signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%resource waits] FROM sys.dm_os_wait_stats OPTION (RECOMPILE); Higher the single wait stats are not good for the system. Very high value indicates CPU pressure. In my experience, when systems are running smooth and without any glitch the single wait stat is lower than 20%. Again, this number can be debated (and it is from my experience and is not documented anywhere). In other words, lower is better and higher is not good for the system. In future articles we will discuss in detail the various wait types and wait stats and their resolution. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL DMV, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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  • Where is my app.config for SSIS?

    Sometimes when working with SSIS you need to add or change settings in the .NET application configuration file, which can be a bit confusing when you are building a SSIS package not an application. First of all lets review a couple of examples where you may need to do this. You are using referencing an assembly in a Script Task that uses Enterprise Library (aka EntLib), so you need to add the relevant configuration sections and settings, perhaps for the logging application block. You are using using Enterprise Library in a custom task or component, and again you need to add the relevant configuration sections and settings. You are using a web service with Microsoft Web Services Enhancements (WSE) 3.0 and hosting the proxy in SSIS, in an assembly used by your package, and need to add the configuration sections and settings. You need to change behaviours of the .NET framework which can be influenced by a configuration file, such as the System.Net.Mail default SMTP settings. Perhaps you wish to configure System.Net and the httpWebRequest header for parsing unsafe header (useUnsafeHeaderParsing), which will change the way the HTTP Connection manager behaves. You are consuming a WCF service and wish to specify the endpoint in configuration. There are no doubt plenty more examples but each of these requires us to identify the correct configuration file and and make the relevant changes. There are actually several configuration files, each used by a different execution host depending on how you are working with the SSIS package. The folders we need to look in will actually vary depending on the version of SQL Server as well as the processor architecture, but most are all what we can call the Binn folder. The SQL Server 2005 Binn folder is at C:\Program Files\Microsoft SQL Server\90\DTS\Binn\, compared to C:\Program Files\Microsoft SQL Server\100\DTS\Binn\ for SQL Server 2008. If you are on a 64-bit machine then you will see C:\Program Files (x86)\Microsoft SQL Server\90\DTS\Binn\ for the 32-bit executables and C:\Program Files\Microsoft SQL Server\90\DTS\Binn\ for 64-bit, so be sure to check all relevant locations. Of course SQL Server 2008 may have a C:\Program Files (x86)\Microsoft SQL Server\100\DTS\Binn\ on a 64-bit machine too. To recap, the version of SQL Server determines if you look in the 90 or 100 sub-folder under SQL Server in Program Files (C:\Program Files\Microsoft SQL Server\nn\) . If you are running a 64-bit operating system then you will have two instances program files, C:\Program Files (x86)\ for 32-bit and  C:\Program Files\ for 64-bit. You may wish to check both depending on what you are doing, but this is covered more under each section below. There are a total of five specific configuration files that you may need to change, each one is detailed below: DTExec.exe.config DTExec.exe is the standalone command line tool used for executing SSIS packages, and therefore it is an execution host with an app.config file. e.g. C:\Program Files\Microsoft SQL Server\90\DTS\Binn\DTExec.exe.config The file can be found in both the 32-bit and 64-bit Binn folders. DtsDebugHost.exe.config DtsDebugHost.exe is the execution host used by Business Intelligence Development Studio (BIDS) / Visual Studio when executing a package from the designer in debug mode, which is the default behaviour. e.g. C:\Program Files\Microsoft SQL Server\90\DTS\Binn\DtsDebugHost.exe.config The file can be found in both the 32-bit and 64-bit Binn folders. This may surprise some people as Visual Studio is only 32-bit, but thankfully the debugger supports both. This can be set in the project properties, see the Run64BitRuntime property (true or false) in the Debugging pane of the Project Properties. dtshost.exe.config dtshost.exe is the execution host used by what I think of as the built-in features of SQL Server such as SQL Server Agent e.g. C:\Program Files\Microsoft SQL Server\90\DTS\Binn\dtshost.exe.config This file can be found in both the 32-bit and 64-bit Binn folders devenv.exe.config Something slightly different is devenv.exe which is Visual Studio. This configuration file may also need changing if you need a feature at design-time such as in a Task Editor or Connection Manager editor. Visual Studio 2005 for SQL Server 2005  - C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\devenv.exe.config Visual Studio 2008 for SQL Server 2008  - C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE\devenv.exe.config Visual Studio is only available for 32-bit so on a 64-bit machine you will have to look in C:\Program Files (x86)\ only. DTExecUI.exe.config The DTExec UI tool can also have a configuration file and these cab be found under the Tools folders for SQL Sever as shown below. C:\Program Files\Microsoft SQL Server\90\Tools\Binn\VSShell\Common7\IDE\DTExecUI.exe C:\Program Files\Microsoft SQL Server\100\Tools\Binn\VSShell\Common7\IDE\DTExecUI.exe A configuration file may not exist, but if you can find the matching executable you know you are in the right place so can go ahead and add a new file yourself. In summary we have covered the assembly configuration files for all of the standard methods of building and running a SSIS package, but obviously if you are working programmatically you will need to make the relevant modifications to your program’s app.config as well.

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  • Rails requires Rubygems but I have the gems

    - by fogonthedowns
    Update I notice that which ruby and whereis ruby are different locations which ruby /opt/local/bin/ruby whereis ruby /usr/bin/ruby I recently upgraded ruby to ruby 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin10] and I think I broke rails. When I attempt to load rails. I get an odd message. Please help! $ ruby script/server Rails requires RubyGems = 1.3.2. Please install RubyGems and try again: http://rubygems.rubyforge.org $ rails -v Rails 3.0.0.beta $ gem -v 1.3.6 $ which gem /usr/bin/gem $ whereis gem /usr/bin/gem $ which rails /usr/bin/rails $ whereis rails /usr/bin/rails $ /usr/bin/gem -v 1.3.6 $ /usr/bin/rails -v Rails 3.0.0.beta $ ruby script/console Rails requires RubyGems >= 1.3.2. Please install RubyGems and try again: http://rubygems.rubyforge.org $ gem list rails *** LOCAL GEMS *** rails (3.0.0.beta, 2.3.5, 2.2.2, 1.2.6) $ gem list *** LOCAL GEMS *** abstract (1.0.0) actionmailer (3.0.0.beta, 2.3.5, 2.2.2, 1.3.6) actionpack (3.0.0.beta, 2.3.5, 2.2.2, 1.13.6) actionwebservice (1.2.6) activemerchant (1.4.1) activemodel (3.0.0.beta) activerecord (3.0.0.beta, 2.3.5, 2.2.2, 1.15.6) activerecord-tableless (0.1.0) activeresource (3.0.0.beta, 2.3.5, 2.2.2) activesupport (3.0.0.beta, 2.3.5, 2.2.2, 1.4.4) acts_as_ferret (0.4.3) arel (0.2.pre) authlogic (2.1.3) builder (2.1.2) bundler (0.9.3) calendar_date_select (1.15) capistrano (2.5.2) cgi_multipart_eof_fix (2.5.0) chronic (0.2.3) columnize (0.3.1) compass (0.8.17) daemons (1.0.10) dnssd (0.6.0) erubis (2.6.5) fastercsv (1.5.0) fastthread (1.0.1) fcgi (0.8.7) ferret (0.11.6) flay (1.4.0) flog (2.4.0) gbarcode (0.98.16) gem_plugin (0.2.3) git (1.2.5) haml (2.2.15) haml-edge (2.3.100) highline (1.5.0) hoe (2.4.0) hpricot (0.6.164) i18n (0.3.3) javan-whenever (0.3.7) jeweler (1.4.0) jscruggs-metric_fu (1.1.5) json_pure (1.2.0) libxml-ruby (1.1.2) linecache (0.43) mail (2.1.2) mechanize (0.9.3) memcache-client (1.7.8) mime-types (1.16) mislav-will_paginate (2.3.11) mocha (0.9.7) mojombo-chronic (0.3.0) mongrel (1.1.5) needle (1.3.0) net-scp (1.0.1) net-sftp (2.0.1, 1.1.1) net-ssh (2.0.4, 1.1.4) net-ssh-gateway (1.0.0) nifty-generators (0.3.0) nokogiri (1.4.0) openrain-action_mailer_tls (1.1.3) passenger (2.2.5) polyglot (0.2.9) prawn (0.6.3) prawn-core (0.6.3) prawn-format (0.2.3) prawn-layout (0.3.2) prawn-security (0.1.1) rack (1.1.0, 1.0.1) rack-mount (0.4.5) rack-test (0.5.3) rails (3.0.0.beta, 2.3.5, 2.2.2, 1.2.6) railties (3.0.0.beta) rake (0.8.7, 0.8.3) rake-compiler (0.6.0) RedCloth (4.1.1) reek (1.2.6) relevance-rcov (0.9.2.1) rmagick (2.12.2) roodi (2.1.0) rsl-stringex (1.0.3) rspec (1.2.9) rspec-rails (1.2.9) ruby-debug (0.10.3) ruby-debug-base (0.10.3) ruby-openid (2.1.2) ruby-yadis (0.3.4) ruby2ruby (1.2.4) ruby_parser (2.0.4) rubyforge (2.0.3) rubygems-update (1.3.6, 1.3.5) rubynode (0.1.5) searchlogic (2.3.9) sexp_processor (3.0.3) spree (0.9.4) sqlite3-ruby (1.2.5, 1.2.4) termios (0.9.4) test-unit (2.0.5) text-format (1.0.0) text-hyphen (1.0.0) thor (0.13.0) tlsmail (0.0.1) topfunky-gruff (0.3.5) treetop (1.4.3) tzinfo (0.3.16) xmpp4r (0.4)

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  • 8 Things You Can Do In Android’s Developer Options

    - by Chris Hoffman
    The Developer Options menu in Android is a hidden menu with a variety of advanced options. These options are intended for developers, but many of them will be interesting to geeks. You’ll have to perform a secret handshake to enable the Developer Options menu in the Settings screen, as it’s hidden from Android users by default. Follow the simple steps to quickly enable Developer Options. Enable USB Debugging “USB debugging” sounds like an option only an Android developer would need, but it’s probably the most widely used hidden option in Android. USB debugging allows applications on your computer to interface with your Android phone over the USB connection. This is required for a variety of advanced tricks, including rooting an Android phone, unlocking it, installing a custom ROM, or even using a desktop program that captures screenshots of your Android device’s screen. You can also use ADB commands to push and pull files between your device and your computer or create and restore complete local backups of your Android device without rooting. USB debugging can be a security concern, as it gives computers you plug your device into access to your phone. You could plug your device into a malicious USB charging port, which would try to compromise you. That’s why Android forces you to agree to a prompt every time you plug your device into a new computer with USB debugging enabled. Set a Desktop Backup Password If you use the above ADB trick to create local backups of your Android device over USB, you can protect them with a password with the Set a desktop backup password option here. This password encrypts your backups to secure them, so you won’t be able to access them if you forget the password. Disable or Speed Up Animations When you move between apps and screens in Android, you’re spending some of that time looking at animations and waiting for them to go away. You can disable these animations entirely by changing the Window animation scale, Transition animation scale, and Animator duration scale options here. If you like animations but just wish they were faster, you can speed them up. On a fast phone or tablet, this can make switching between apps nearly instant. If you thought your Android phone was speedy before, just try disabling animations and you’ll be surprised how much faster it can seem. Force-Enable FXAA For OpenGL Games If you have a high-end phone or tablet with great graphics performance and you play 3D games on it, there’s a way to make those games look even better. Just go to the Developer Options screen and enable the Force 4x MSAA option. This will force Android to use 4x multisample anti-aliasing in OpenGL ES 2.0 games and other apps. This requires more graphics power and will probably drain your battery a bit faster, but it will improve image quality in some games. This is a bit like force-enabling antialiasing using the NVIDIA Control Panel on a Windows gaming PC. See How Bad Task Killers Are We’ve written before about how task killers are worse than useless on Android. If you use a task killer, you’re just slowing down your system by throwing out cached data and forcing Android to load apps from system storage whenever you open them again. Don’t believe us? Enable the Don’t keep activities option on the Developer options screen and Android will force-close every app you use as soon as you exit it. Enable this app and use your phone normally for a few minutes — you’ll see just how harmful throwing out all that cached data is and how much it will slow down your phone. Don’t actually use this option unless you want to see how bad it is! It will make your phone perform much more slowly — there’s a reason Google has hidden these options away from average users who might accidentally change them. Fake Your GPS Location The Allow mock locations option allows you to set fake GPS locations, tricking Android into thinking you’re at a location where you actually aren’t. Use this option along with an app like Fake GPS location and you can trick your Android device and the apps running on it into thinking you’re at locations where you actually aren’t. How would this be useful? Well, you could fake a GPS check-in at a location without actually going there or confuse your friends in a location-tracking app by seemingly teleporting around the world. Stay Awake While Charging You can use Android’s Daydream Mode to display certain apps while charging your device. If you want to force Android to display a standard Android app that hasn’t been designed for Daydream Mode, you can enable the Stay awake option here. Android will keep your device’s screen on while charging and won’t turn it off. It’s like Daydream Mode, but can support any app and allows users to interact with them. Show Always-On-Top CPU Usage You can view CPU usage data by toggling the Show CPU usage option to On. This information will appear on top of whatever app you’re using. If you’re a Linux user, the three numbers on top probably look familiar — they represent the system load average. From left to right, the numbers represent your system load over the last one, five, and fifteen minutes. This isn’t the kind of thing you’d want enabled most of the time, but it can save you from having to install third-party floating CPU apps if you want to see CPU usage information for some reason. Most of the other options here will only be useful to developers debugging their Android apps. You shouldn’t start changing options you don’t understand. If you want to undo any of these changes, you can quickly erase all your custom options by sliding the switch at the top of the screen to Off.     

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  • /etc/rc.local not being run on Ubuntu Desktop Install

    - by loosecannon
    I have been trying to get sphinx to run at boot, so I added some lines to /etc/rc.local but nothing happens when I start up. If i run it manually it works however. /etc/init.d/rc.local start works fine as does /etc/rc.local It's listed in the default runlevel and is all executable but it does not work. I am considering writing a separate init.d script to do the same thing but that's a lot of work for a simple task dumbledore:/etc/init.d# ls -l rc* -rwxr-xr-x 1 root root 8863 2009-09-07 13:58 rc -rwxr-xr-x 1 root root 801 2009-09-07 13:58 rc.local -rwxr-xr-x 1 root root 117 2009-09-07 13:58 rcS dumbledore:/etc/init.d# ls /etc/rc.local -l -rwxr-xr-x 1 root root 491 2011-05-14 16:13 /etc/rc.local dumbledore:/etc/init.d# runlevel N 2 dumbledore:/etc/init.d# ls /etc/rc2.d/ -l total 4 lrwxrwxrwx 1 root root 18 2011-04-22 18:53 K08vmware -> /etc/init.d/vmware -rw-r--r-- 1 root root 677 2011-03-28 15:10 README lrwxrwxrwx 1 root root 18 2011-04-22 18:53 S19vmware -> /etc/init.d/vmware lrwxrwxrwx 1 root root 18 2011-05-15 14:09 S20ddclient -> ../init.d/ddclient lrwxrwxrwx 1 root root 20 2011-03-10 18:00 S20fancontrol -> ../init.d/fancontrol lrwxrwxrwx 1 root root 20 2011-03-10 18:00 S20kerneloops -> ../init.d/kerneloops lrwxrwxrwx 1 root root 27 2011-03-10 18:00 S20speech-dispatcher -> ../init.d/speech-dispatcher lrwxrwxrwx 1 root root 19 2011-03-10 18:00 S25bluetooth -> ../init.d/bluetooth lrwxrwxrwx 1 root root 20 2011-03-10 18:00 S50pulseaudio -> ../init.d/pulseaudio lrwxrwxrwx 1 root root 15 2011-03-10 18:00 S50rsync -> ../init.d/rsync lrwxrwxrwx 1 root root 15 2011-03-10 18:00 S50saned -> ../init.d/saned lrwxrwxrwx 1 root root 19 2011-03-10 18:00 S70dns-clean -> ../init.d/dns-clean lrwxrwxrwx 1 root root 18 2011-03-10 18:00 S70pppd-dns -> ../init.d/pppd-dns lrwxrwxrwx 1 root root 14 2011-05-07 11:22 S75sudo -> ../init.d/sudo lrwxrwxrwx 1 root root 24 2011-03-10 18:00 S90binfmt-support -> ../init.d/binfmt-support lrwxrwxrwx 1 root root 17 2011-05-12 21:18 S91apache2 -> ../init.d/apache2 lrwxrwxrwx 1 root root 22 2011-03-10 18:00 S99acpi-support -> ../init.d/acpi-support lrwxrwxrwx 1 root root 21 2011-03-10 18:00 S99grub-common -> ../init.d/grub-common lrwxrwxrwx 1 root root 18 2011-03-10 18:00 S99ondemand -> ../init.d/ondemand lrwxrwxrwx 1 root root 18 2011-03-10 18:00 S99rc.local -> ../init.d/rc.local dumbledore:/etc/init.d# cat /etc/rc.local #!/bin/sh -e # # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing. # Start sphinx daemon for rails app on startup # Added 2011-05-13 # Cannon Matthews cd /var/www/extemp /usr/bin/rake ts:config /usr/bin/rake ts:start touch ./tmp/ohyeah cd - exit 0 dumbledore:/etc/init.d# cat /etc/init.d/rc.local #! /bin/sh ### BEGIN INIT INFO # Provides: rc.local # Required-Start: $remote_fs $syslog $all # Required-Stop: # Default-Start: 2 3 4 5 # Default-Stop: # Short-Description: Run /etc/rc.local if it exist ### END INIT INFO PATH=/sbin:/usr/sbin:/bin:/usr/bin . /lib/init/vars.sh . /lib/lsb/init-functions do_start() { if [ -x /etc/rc.local ]; then [ "$VERBOSE" != no ] && log_begin_msg "Running local boot scripts (/etc/rc.local)" /etc/rc.local ES=$? [ "$VERBOSE" != no ] && log_end_msg $ES return $ES fi } case "$1" in start) do_start ;; restart|reload|force-reload) echo "Error: argument '$1' not supported" >&2 exit 3 ;; stop) ;; *) echo "Usage: $0 start|stop" >&2 exit 3 ;; esac

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  • Metro: Creating an IndexedDbDataSource for WinJS

    - by Stephen.Walther
    The goal of this blog entry is to describe how you can create custom data sources which you can use with the controls in the WinJS library. In particular, I explain how you can create an IndexedDbDataSource which you can use to store and retrieve data from an IndexedDB database. If you want to skip ahead, and ignore all of the fascinating content in-between, I’ve included the complete code for the IndexedDbDataSource at the very bottom of this blog entry. What is IndexedDB? IndexedDB is a database in the browser. You can use the IndexedDB API with all modern browsers including Firefox, Chrome, and Internet Explorer 10. And, of course, you can use IndexedDB with Metro style apps written with JavaScript. If you need to persist data in a Metro style app written with JavaScript then IndexedDB is a good option. Each Metro app can only interact with its own IndexedDB databases. And, IndexedDB provides you with transactions, indices, and cursors – the elements of any modern database. An IndexedDB database might be different than the type of database that you normally use. An IndexedDB database is an object-oriented database and not a relational database. Instead of storing data in tables, you store data in object stores. You store JavaScript objects in an IndexedDB object store. You create new IndexedDB object stores by handling the upgradeneeded event when you attempt to open a connection to an IndexedDB database. For example, here’s how you would both open a connection to an existing database named TasksDB and create the TasksDB database when it does not already exist: var reqOpen = window.indexedDB.open(“TasksDB”, 2); reqOpen.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement: true }); }; reqOpen.onsuccess = function () { var db = reqOpen.result; // Do something with db }; When you call window.indexedDB.open(), and the database does not already exist, then the upgradeneeded event is raised. In the code above, the upgradeneeded handler creates a new object store named tasks. The new object store has an auto-increment column named id which acts as the primary key column. If the database already exists with the right version, and you call window.indexedDB.open(), then the success event is raised. At that point, you have an open connection to the existing database and you can start doing something with the database. You use asynchronous methods to interact with an IndexedDB database. For example, the following code illustrates how you would add a new object to the tasks object store: var transaction = db.transaction(“tasks”, “readwrite”); var reqAdd = transaction.objectStore(“tasks”).add({ name: “Feed the dog” }); reqAdd.onsuccess = function() { // Tasks added successfully }; The code above creates a new database transaction, adds a new task to the tasks object store, and handles the success event. If the new task gets added successfully then the success event is raised. Creating a WinJS IndexedDbDataSource The most powerful control in the WinJS library is the ListView control. This is the control that you use to display a collection of items. If you want to display data with a ListView control, you need to bind the control to a data source. The WinJS library includes two objects which you can use as a data source: the List object and the StorageDataSource object. The List object enables you to represent a JavaScript array as a data source and the StorageDataSource enables you to represent the file system as a data source. If you want to bind an IndexedDB database to a ListView then you have a choice. You can either dump the items from the IndexedDB database into a List object or you can create a custom data source. I explored the first approach in a previous blog entry. In this blog entry, I explain how you can create a custom IndexedDB data source. Implementing the IListDataSource Interface You create a custom data source by implementing the IListDataSource interface. This interface contains the contract for the methods which the ListView needs to interact with a data source. The easiest way to implement the IListDataSource interface is to derive a new object from the base VirtualizedDataSource object. The VirtualizedDataSource object requires a data adapter which implements the IListDataAdapter interface. Yes, because of the number of objects involved, this is a little confusing. Your code ends up looking something like this: var IndexedDbDataSource = WinJS.Class.derive( WinJS.UI.VirtualizedDataSource, function (dbName, dbVersion, objectStoreName, upgrade, error) { this._adapter = new IndexedDbDataAdapter(dbName, dbVersion, objectStoreName, upgrade, error); this._baseDataSourceConstructor(this._adapter); }, { nuke: function () { this._adapter.nuke(); }, remove: function (key) { this._adapter.removeInternal(key); } } ); The code above is used to create a new class named IndexedDbDataSource which derives from the base VirtualizedDataSource class. In the constructor for the new class, the base class _baseDataSourceConstructor() method is called. A data adapter is passed to the _baseDataSourceConstructor() method. The code above creates a new method exposed by the IndexedDbDataSource named nuke(). The nuke() method deletes all of the objects from an object store. The code above also overrides a method named remove(). Our derived remove() method accepts any type of key and removes the matching item from the object store. Almost all of the work of creating a custom data source goes into building the data adapter class. The data adapter class implements the IListDataAdapter interface which contains the following methods: · change() · getCount() · insertAfter() · insertAtEnd() · insertAtStart() · insertBefore() · itemsFromDescription() · itemsFromEnd() · itemsFromIndex() · itemsFromKey() · itemsFromStart() · itemSignature() · moveAfter() · moveBefore() · moveToEnd() · moveToStart() · remove() · setNotificationHandler() · compareByIdentity Fortunately, you are not required to implement all of these methods. You only need to implement the methods that you actually need. In the case of the IndexedDbDataSource, I implemented the getCount(), itemsFromIndex(), insertAtEnd(), and remove() methods. If you are creating a read-only data source then you really only need to implement the getCount() and itemsFromIndex() methods. Implementing the getCount() Method The getCount() method returns the total number of items from the data source. So, if you are storing 10,000 items in an object store then this method would return the value 10,000. Here’s how I implemented the getCount() method: getCount: function () { var that = this; return new WinJS.Promise(function (complete, error) { that._getObjectStore().then(function (store) { var reqCount = store.count(); reqCount.onerror = that._error; reqCount.onsuccess = function (evt) { complete(evt.target.result); }; }); }); } The first thing that you should notice is that the getCount() method returns a WinJS promise. This is a requirement. The getCount() method is asynchronous which is a good thing because all of the IndexedDB methods (at least the methods implemented in current browsers) are also asynchronous. The code above retrieves an object store and then uses the IndexedDB count() method to get a count of the items in the object store. The value is returned from the promise by calling complete(). Implementing the itemsFromIndex method When a ListView displays its items, it calls the itemsFromIndex() method. By default, it calls this method multiple times to get different ranges of items. Three parameters are passed to the itemsFromIndex() method: the requestIndex, countBefore, and countAfter parameters. The requestIndex indicates the index of the item from the database to show. The countBefore and countAfter parameters represent hints. These are integer values which represent the number of items before and after the requestIndex to retrieve. Again, these are only hints and you can return as many items before and after the request index as you please. Here’s how I implemented the itemsFromIndex method: itemsFromIndex: function (requestIndex, countBefore, countAfter) { var that = this; return new WinJS.Promise(function (complete, error) { that.getCount().then(function (count) { if (requestIndex >= count) { return WinJS.Promise.wrapError(new WinJS.ErrorFromName(WinJS.UI.FetchError.doesNotExist)); } var startIndex = Math.max(0, requestIndex - countBefore); var endIndex = Math.min(count, requestIndex + countAfter + 1); that._getObjectStore().then(function (store) { var index = 0; var items = []; var req = store.openCursor(); req.onerror = that._error; req.onsuccess = function (evt) { var cursor = evt.target.result; if (index < startIndex) { index = startIndex; cursor.advance(startIndex); return; } if (cursor && index < endIndex) { index++; items.push({ key: cursor.value[store.keyPath].toString(), data: cursor.value }); cursor.continue(); return; } results = { items: items, offset: requestIndex - startIndex, totalCount: count }; complete(results); }; }); }); }); } In the code above, a cursor is used to iterate through the objects in an object store. You fetch the next item in the cursor by calling either the cursor.continue() or cursor.advance() method. The continue() method moves forward by one object and the advance() method moves forward a specified number of objects. Each time you call continue() or advance(), the success event is raised again. If the cursor is null then you know that you have reached the end of the cursor and you can return the results. Some things to be careful about here. First, the return value from the itemsFromIndex() method must implement the IFetchResult interface. In particular, you must return an object which has an items, offset, and totalCount property. Second, each item in the items array must implement the IListItem interface. Each item should have a key and a data property. Implementing the insertAtEnd() Method When creating the IndexedDbDataSource, I wanted to go beyond creating a simple read-only data source and support inserting and deleting objects. If you want to support adding new items with your data source then you need to implement the insertAtEnd() method. Here’s how I implemented the insertAtEnd() method for the IndexedDbDataSource: insertAtEnd:function(unused, data) { var that = this; return new WinJS.Promise(function (complete, error) { that._getObjectStore("readwrite").done(function(store) { var reqAdd = store.add(data); reqAdd.onerror = that._error; reqAdd.onsuccess = function (evt) { var reqGet = store.get(evt.target.result); reqGet.onerror = that._error; reqGet.onsuccess = function (evt) { var newItem = { key:evt.target.result[store.keyPath].toString(), data:evt.target.result } complete(newItem); }; }; }); }); } When implementing the insertAtEnd() method, you need to be careful to return an object which implements the IItem interface. In particular, you should return an object that has a key and a data property. The key must be a string and it uniquely represents the new item added to the data source. The value of the data property represents the new item itself. Implementing the remove() Method Finally, you use the remove() method to remove an item from the data source. You call the remove() method with the key of the item which you want to remove. Implementing the remove() method in the case of the IndexedDbDataSource was a little tricky. The problem is that an IndexedDB object store uses an integer key and the VirtualizedDataSource requires a string key. For that reason, I needed to override the remove() method in the derived IndexedDbDataSource class like this: var IndexedDbDataSource = WinJS.Class.derive( WinJS.UI.VirtualizedDataSource, function (dbName, dbVersion, objectStoreName, upgrade, error) { this._adapter = new IndexedDbDataAdapter(dbName, dbVersion, objectStoreName, upgrade, error); this._baseDataSourceConstructor(this._adapter); }, { nuke: function () { this._adapter.nuke(); }, remove: function (key) { this._adapter.removeInternal(key); } } ); When you call remove(), you end up calling a method of the IndexedDbDataAdapter named removeInternal() . Here’s what the removeInternal() method looks like: setNotificationHandler: function (notificationHandler) { this._notificationHandler = notificationHandler; }, removeInternal: function(key) { var that = this; return new WinJS.Promise(function (complete, error) { that._getObjectStore("readwrite").done(function (store) { var reqDelete = store.delete (key); reqDelete.onerror = that._error; reqDelete.onsuccess = function (evt) { that._notificationHandler.removed(key.toString()); complete(); }; }); }); } The removeInternal() method calls the IndexedDB delete() method to delete an item from the object store. If the item is deleted successfully then the _notificationHandler.remove() method is called. Because we are not implementing the standard IListDataAdapter remove() method, we need to notify the data source (and the ListView control bound to the data source) that an item has been removed. The way that you notify the data source is by calling the _notificationHandler.remove() method. Notice that we get the _notificationHandler in the code above by implementing another method in the IListDataAdapter interface: the setNotificationHandler() method. You can raise the following types of notifications using the _notificationHandler: · beginNotifications() · changed() · endNotifications() · inserted() · invalidateAll() · moved() · removed() · reload() These methods are all part of the IListDataNotificationHandler interface in the WinJS library. Implementing the nuke() Method I wanted to implement a method which would remove all of the items from an object store. Therefore, I created a method named nuke() which calls the IndexedDB clear() method: nuke: function () { var that = this; return new WinJS.Promise(function (complete, error) { that._getObjectStore("readwrite").done(function (store) { var reqClear = store.clear(); reqClear.onerror = that._error; reqClear.onsuccess = function (evt) { that._notificationHandler.reload(); complete(); }; }); }); } Notice that the nuke() method calls the _notificationHandler.reload() method to notify the ListView to reload all of the items from its data source. Because we are implementing a custom method here, we need to use the _notificationHandler to send an update. Using the IndexedDbDataSource To illustrate how you can use the IndexedDbDataSource, I created a simple task list app. You can add new tasks, delete existing tasks, and nuke all of the tasks. You delete an item by selecting an item (swipe or right-click) and clicking the Delete button. Here’s the HTML page which contains the ListView, the form for adding new tasks, and the buttons for deleting and nuking tasks: <!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>DataSources</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.1.0.RC/css/ui-dark.css" rel="stylesheet" /> <script src="//Microsoft.WinJS.1.0.RC/js/base.js"></script> <script src="//Microsoft.WinJS.1.0.RC/js/ui.js"></script> <!-- DataSources references --> <link href="indexedDb.css" rel="stylesheet" /> <script type="text/javascript" src="indexedDbDataSource.js"></script> <script src="indexedDb.js"></script> </head> <body> <div id="tmplTask" data-win-control="WinJS.Binding.Template"> <div class="taskItem"> Id: <span data-win-bind="innerText:id"></span> <br /><br /> Name: <span data-win-bind="innerText:name"></span> </div> </div> <div id="lvTasks" data-win-control="WinJS.UI.ListView" data-win-options="{ itemTemplate: select('#tmplTask'), selectionMode: 'single' }"></div> <form id="frmAdd"> <fieldset> <legend>Add Task</legend> <label>New Task</label> <input id="inputTaskName" required /> <button>Add</button> </fieldset> </form> <button id="btnNuke">Nuke</button> <button id="btnDelete">Delete</button> </body> </html> And here is the JavaScript code for the TaskList app: /// <reference path="//Microsoft.WinJS.1.0.RC/js/base.js" /> /// <reference path="//Microsoft.WinJS.1.0.RC/js/ui.js" /> function init() { WinJS.UI.processAll().done(function () { var lvTasks = document.getElementById("lvTasks").winControl; // Bind the ListView to its data source var tasksDataSource = new DataSources.IndexedDbDataSource("TasksDB", 1, "tasks", upgrade); lvTasks.itemDataSource = tasksDataSource; // Wire-up Add, Delete, Nuke buttons document.getElementById("frmAdd").addEventListener("submit", function (evt) { evt.preventDefault(); tasksDataSource.beginEdits(); tasksDataSource.insertAtEnd(null, { name: document.getElementById("inputTaskName").value }).done(function (newItem) { tasksDataSource.endEdits(); document.getElementById("frmAdd").reset(); lvTasks.ensureVisible(newItem.index); }); }); document.getElementById("btnDelete").addEventListener("click", function () { if (lvTasks.selection.count() == 1) { lvTasks.selection.getItems().done(function (items) { tasksDataSource.remove(items[0].data.id); }); } }); document.getElementById("btnNuke").addEventListener("click", function () { tasksDataSource.nuke(); }); // This method is called to initialize the IndexedDb database function upgrade(evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement: true }); } }); } document.addEventListener("DOMContentLoaded", init); The IndexedDbDataSource is created and bound to the ListView control with the following two lines of code: var tasksDataSource = new DataSources.IndexedDbDataSource("TasksDB", 1, "tasks", upgrade); lvTasks.itemDataSource = tasksDataSource; The IndexedDbDataSource is created with four parameters: the name of the database to create, the version of the database to create, the name of the object store to create, and a function which contains code to initialize the new database. The upgrade function creates a new object store named tasks with an auto-increment property named id: function upgrade(evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement: true }); } The Complete Code for the IndexedDbDataSource Here’s the complete code for the IndexedDbDataSource: (function () { /************************************************ * The IndexedDBDataAdapter enables you to work * with a HTML5 IndexedDB database. *************************************************/ var IndexedDbDataAdapter = WinJS.Class.define( function (dbName, dbVersion, objectStoreName, upgrade, error) { this._dbName = dbName; // database name this._dbVersion = dbVersion; // database version this._objectStoreName = objectStoreName; // object store name this._upgrade = upgrade; // database upgrade script this._error = error || function (evt) { console.log(evt.message); }; }, { /******************************************* * IListDataAdapter Interface Methods ********************************************/ getCount: function () { var that = this; return new WinJS.Promise(function (complete, error) { that._getObjectStore().then(function (store) { var reqCount = store.count(); reqCount.onerror = that._error; reqCount.onsuccess = function (evt) { complete(evt.target.result); }; }); }); }, itemsFromIndex: function (requestIndex, countBefore, countAfter) { var that = this; return new WinJS.Promise(function (complete, error) { that.getCount().then(function (count) { if (requestIndex >= count) { return WinJS.Promise.wrapError(new WinJS.ErrorFromName(WinJS.UI.FetchError.doesNotExist)); } var startIndex = Math.max(0, requestIndex - countBefore); var endIndex = Math.min(count, requestIndex + countAfter + 1); that._getObjectStore().then(function (store) { var index = 0; var items = []; var req = store.openCursor(); req.onerror = that._error; req.onsuccess = function (evt) { var cursor = evt.target.result; if (index < startIndex) { index = startIndex; cursor.advance(startIndex); return; } if (cursor && index < endIndex) { index++; items.push({ key: cursor.value[store.keyPath].toString(), data: cursor.value }); cursor.continue(); return; } results = { items: items, offset: requestIndex - startIndex, totalCount: count }; complete(results); }; }); }); }); }, insertAtEnd:function(unused, data) { var that = this; return new WinJS.Promise(function (complete, error) { that._getObjectStore("readwrite").done(function(store) { var reqAdd = store.add(data); reqAdd.onerror = that._error; reqAdd.onsuccess = function (evt) { var reqGet = store.get(evt.target.result); reqGet.onerror = that._error; reqGet.onsuccess = function (evt) { var newItem = { key:evt.target.result[store.keyPath].toString(), data:evt.target.result } complete(newItem); }; }; }); }); }, setNotificationHandler: function (notificationHandler) { this._notificationHandler = notificationHandler; }, /***************************************** * IndexedDbDataSource Method ******************************************/ removeInternal: function(key) { var that = this; return new WinJS.Promise(function (complete, error) { that._getObjectStore("readwrite").done(function (store) { var reqDelete = store.delete (key); reqDelete.onerror = that._error; reqDelete.onsuccess = function (evt) { that._notificationHandler.removed(key.toString()); complete(); }; }); }); }, nuke: function () { var that = this; return new WinJS.Promise(function (complete, error) { that._getObjectStore("readwrite").done(function (store) { var reqClear = store.clear(); reqClear.onerror = that._error; reqClear.onsuccess = function (evt) { that._notificationHandler.reload(); complete(); }; }); }); }, /******************************************* * Private Methods ********************************************/ _ensureDbOpen: function () { var that = this; // Try to get cached Db if (that._cachedDb) { return WinJS.Promise.wrap(that._cachedDb); } // Otherwise, open the database return new WinJS.Promise(function (complete, error, progress) { var reqOpen = window.indexedDB.open(that._dbName, that._dbVersion); reqOpen.onerror = function (evt) { error(); }; reqOpen.onupgradeneeded = function (evt) { that._upgrade(evt); that._notificationHandler.invalidateAll(); }; reqOpen.onsuccess = function () { that._cachedDb = reqOpen.result; complete(that._cachedDb); }; }); }, _getObjectStore: function (type) { type = type || "readonly"; var that = this; return new WinJS.Promise(function (complete, error) { that._ensureDbOpen().then(function (db) { var transaction = db.transaction(that._objectStoreName, type); complete(transaction.objectStore(that._objectStoreName)); }); }); }, _get: function (key) { return new WinJS.Promise(function (complete, error) { that._getObjectStore().done(function (store) { var reqGet = store.get(key); reqGet.onerror = that._error; reqGet.onsuccess = function (item) { complete(item); }; }); }); } } ); var IndexedDbDataSource = WinJS.Class.derive( WinJS.UI.VirtualizedDataSource, function (dbName, dbVersion, objectStoreName, upgrade, error) { this._adapter = new IndexedDbDataAdapter(dbName, dbVersion, objectStoreName, upgrade, error); this._baseDataSourceConstructor(this._adapter); }, { nuke: function () { this._adapter.nuke(); }, remove: function (key) { this._adapter.removeInternal(key); } } ); WinJS.Namespace.define("DataSources", { IndexedDbDataSource: IndexedDbDataSource }); })(); Summary In this blog post, I provided an overview of how you can create a new data source which you can use with the WinJS library. I described how you can create an IndexedDbDataSource which you can use to bind a ListView control to an IndexedDB database. While describing how you can create a custom data source, I explained how you can implement the IListDataAdapter interface. You also learned how to raise notifications — such as a removed or invalidateAll notification — by taking advantage of the methods of the IListDataNotificationHandler interface.

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  • Entity Framework Batch Update and Future Queries

    - by pwelter34
    Entity Framework Extended Library A library the extends the functionality of Entity Framework. Features Batch Update and Delete Future Queries Audit Log Project Package and Source NuGet Package PM> Install-Package EntityFramework.Extended NuGet: http://nuget.org/List/Packages/EntityFramework.Extended Source: http://github.com/loresoft/EntityFramework.Extended Batch Update and Delete A current limitations of the Entity Framework is that in order to update or delete an entity you have to first retrieve it into memory. Now in most scenarios this is just fine. There are however some senerios where performance would suffer. Also, for single deletes, the object must be retrieved before it can be deleted requiring two calls to the database. Batch update and delete eliminates the need to retrieve and load an entity before modifying it. Deleting //delete all users where FirstName matches context.Users.Delete(u => u.FirstName == "firstname"); Update //update all tasks with status of 1 to status of 2 context.Tasks.Update( t => t.StatusId == 1, t => new Task {StatusId = 2}); //example of using an IQueryable as the filter for the update var users = context.Users .Where(u => u.FirstName == "firstname"); context.Users.Update( users, u => new User {FirstName = "newfirstname"}); Future Queries Build up a list of queries for the data that you need and the first time any of the results are accessed, all the data will retrieved in one round trip to the database server. Reducing the number of trips to the database is a great. Using this feature is as simple as appending .Future() to the end of your queries. To use the Future Queries, make sure to import the EntityFramework.Extensions namespace. Future queries are created with the following extension methods... Future() FutureFirstOrDefault() FutureCount() Sample // build up queries var q1 = db.Users .Where(t => t.EmailAddress == "[email protected]") .Future(); var q2 = db.Tasks .Where(t => t.Summary == "Test") .Future(); // this triggers the loading of all the future queries var users = q1.ToList(); In the example above, there are 2 queries built up, as soon as one of the queries is enumerated, it triggers the batch load of both queries. // base query var q = db.Tasks.Where(t => t.Priority == 2); // get total count var q1 = q.FutureCount(); // get page var q2 = q.Skip(pageIndex).Take(pageSize).Future(); // triggers execute as a batch int total = q1.Value; var tasks = q2.ToList(); In this example, we have a common senerio where you want to page a list of tasks. In order for the GUI to setup the paging control, you need a total count. With Future, we can batch together the queries to get all the data in one database call. Future queries work by creating the appropriate IFutureQuery object that keeps the IQuerable. The IFutureQuery object is then stored in IFutureContext.FutureQueries list. Then, when one of the IFutureQuery objects is enumerated, it calls back to IFutureContext.ExecuteFutureQueries() via the LoadAction delegate. ExecuteFutureQueries builds a batch query from all the stored IFutureQuery objects. Finally, all the IFutureQuery objects are updated with the results from the query. Audit Log The Audit Log feature will capture the changes to entities anytime they are submitted to the database. The Audit Log captures only the entities that are changed and only the properties on those entities that were changed. The before and after values are recorded. AuditLogger.LastAudit is where this information is held and there is a ToXml() method that makes it easy to turn the AuditLog into xml for easy storage. The AuditLog can be customized via attributes on the entities or via a Fluent Configuration API. Fluent Configuration // config audit when your application is starting up... var auditConfiguration = AuditConfiguration.Default; auditConfiguration.IncludeRelationships = true; auditConfiguration.LoadRelationships = true; auditConfiguration.DefaultAuditable = true; // customize the audit for Task entity auditConfiguration.IsAuditable<Task>() .NotAudited(t => t.TaskExtended) .FormatWith(t => t.Status, v => FormatStatus(v)); // set the display member when status is a foreign key auditConfiguration.IsAuditable<Status>() .DisplayMember(t => t.Name); Create an Audit Log var db = new TrackerContext(); var audit = db.BeginAudit(); // make some updates ... db.SaveChanges(); var log = audit.LastLog;

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  • SQL SERVER – SSIS Parameters in Parent-Child ETL Architectures – Notes from the Field #040

    - by Pinal Dave
    [Notes from Pinal]: SSIS is very well explored subject, however, there are so many interesting elements when we read, we learn something new. A similar concept has been Parent-Child ETL architecture’s relationship in SSIS. Linchpin People are database coaches and wellness experts for a data driven world. In this 40th episode of the Notes from the Fields series database expert Tim Mitchell (partner at Linchpin People) shares very interesting conversation related to how to understand SSIS Parameters in Parent-Child ETL Architectures. In this brief Notes from the Field post, I will review the use of SSIS parameters in parent-child ETL architectures. A very common design pattern used in SQL Server Integration Services is one I call the parent-child pattern.  Simply put, this is a pattern in which packages are executed by other packages.  An ETL infrastructure built using small, single-purpose packages is very often easier to develop, debug, and troubleshoot than large, monolithic packages.  For a more in-depth look at parent-child architectures, check out my earlier blog post on this topic. When using the parent-child design pattern, you will frequently need to pass values from the calling (parent) package to the called (child) package.  In older versions of SSIS, this process was possible but not necessarily simple.  When using SSIS 2005 or 2008, or even when using SSIS 2012 or 2014 in package deployment mode, you would have to create package configurations to pass values from parent to child packages.  Package configurations, while effective, were not the easiest tool to work with.  Fortunately, starting with SSIS in SQL Server 2012, you can now use package parameters for this purpose. In the example I will use for this demonstration, I’ll create two packages: one intended for use as a child package, and the other configured to execute said child package.  In the parent package I’m going to build a for each loop container in SSIS, and use package parameters to pass in a value – specifically, a ClientID – for each iteration of the loop.  The child package will be executed from within the for each loop, and will create one output file for each client, with the source query and filename dependent on the ClientID received from the parent package. Configuring the Child and Parent Packages When you create a new package, you’ll see the Parameters tab at the package level.  Clicking over to that tab allows you to add, edit, or delete package parameters. As shown above, the sample package has two parameters.  Note that I’ve set the name, data type, and default value for each of these.  Also note the column entitled Required: this allows me to specify whether the parameter value is optional (the default behavior) or required for package execution.  In this example, I have one parameter that is required, and the other is not. Let’s shift over to the parent package briefly, and demonstrate how to supply values to these parameters in the child package.  Using the execute package task, you can easily map variable values in the parent package to parameters in the child package. The execute package task in the parent package, shown above, has the variable vThisClient from the parent package mapped to the pClientID parameter shown earlier in the child package.  Note that there is no value mapped to the child package parameter named pOutputFolder.  Since this parameter has the Required property set to False, we don’t have to specify a value for it, which will cause that parameter to use the default value we supplied when designing the child pacakge. The last step in the parent package is to create the for each loop container I mentioned earlier, and place the execute package task inside it.  I’m using an object variable to store the distinct client ID values, and I use that as the iterator for the loop (I describe how to do this more in depth here).  For each iteration of the loop, a different client ID value will be passed into the child package parameter. The final step is to configure the child package to actually do something meaningful with the parameter values passed into it.  In this case, I’ve modified the OleDB source query to use the pClientID value in the WHERE clause of the query to restrict results for each iteration to a single client’s data.  Additionally, I’ll use both the pClientID and pOutputFolder parameters to dynamically build the output filename. As shown, the pClientID is used in the WHERE clause, so we only get the current client’s invoices for each iteration of the loop. For the flat file connection, I’m setting the Connection String property using an expression that engages both of the parameters for this package, as shown above. Parting Thoughts There are many uses for package parameters beyond a simple parent-child design pattern.  For example, you can create standalone packages (those not intended to be used as a child package) and still use parameters.  Parameter values may be supplied to a package directly at runtime by a SQL Server Agent job, through the command line (via dtexec.exe), or through T-SQL. Also, you can also have project parameters as well as package parameters.  Project parameters work in much the same way as package parameters, but the parameters apply to all packages in a project, not just a single package. Conclusion Of the numerous advantages of using catalog deployment model in SSIS 2012 and beyond, package parameters are near the top of the list.  Parameters allow you to easily share values from parent to child packages, enabling more dynamic behavior and better code encapsulation. If you want me to take a look at your server and its settings, or if your server is facing any issue we can Fix Your SQL Server. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • 256 Windows Azure Worker Roles, Windows Kinect and a 90's Text-Based Ray-Tracer

    - by Alan Smith
    For a couple of years I have been demoing a simple render farm hosted in Windows Azure using worker roles and the Azure Storage service. At the start of the presentation I deploy an Azure application that uses 16 worker roles to render a 1,500 frame 3D ray-traced animation. At the end of the presentation, when the animation was complete, I would play the animation delete the Azure deployment. The standing joke with the audience was that it was that it was a “$2 demo”, as the compute charges for running the 16 instances for an hour was $1.92, factor in the bandwidth charges and it’s a couple of dollars. The point of the demo is that it highlights one of the great benefits of cloud computing, you pay for what you use, and if you need massive compute power for a short period of time using Windows Azure can work out very cost effective. The “$2 demo” was great for presenting at user groups and conferences in that it could be deployed to Azure, used to render an animation, and then removed in a one hour session. I have always had the idea of doing something a bit more impressive with the demo, and scaling it from a “$2 demo” to a “$30 demo”. The challenge was to create a visually appealing animation in high definition format and keep the demo time down to one hour.  This article will take a run through how I achieved this. Ray Tracing Ray tracing, a technique for generating high quality photorealistic images, gained popularity in the 90’s with companies like Pixar creating feature length computer animations, and also the emergence of shareware text-based ray tracers that could run on a home PC. In order to render a ray traced image, the ray of light that would pass from the view point must be tracked until it intersects with an object. At the intersection, the color, reflectiveness, transparency, and refractive index of the object are used to calculate if the ray will be reflected or refracted. Each pixel may require thousands of calculations to determine what color it will be in the rendered image. Pin-Board Toys Having very little artistic talent and a basic understanding of maths I decided to focus on an animation that could be modeled fairly easily and would look visually impressive. I’ve always liked the pin-board desktop toys that become popular in the 80’s and when I was working as a 3D animator back in the 90’s I always had the idea of creating a 3D ray-traced animation of a pin-board, but never found the energy to do it. Even if I had a go at it, the render time to produce an animation that would look respectable on a 486 would have been measured in months. PolyRay Back in 1995 I landed my first real job, after spending three years being a beach-ski-climbing-paragliding-bum, and was employed to create 3D ray-traced animations for a CD-ROM that school kids would use to learn physics. I had got into the strange and wonderful world of text-based ray tracing, and was using a shareware ray-tracer called PolyRay. PolyRay takes a text file describing a scene as input and, after a few hours processing on a 486, produced a high quality ray-traced image. The following is an example of a basic PolyRay scene file. background Midnight_Blue   static define matte surface { ambient 0.1 diffuse 0.7 } define matte_white texture { matte { color white } } define matte_black texture { matte { color dark_slate_gray } } define position_cylindrical 3 define lookup_sawtooth 1 define light_wood <0.6, 0.24, 0.1> define median_wood <0.3, 0.12, 0.03> define dark_wood <0.05, 0.01, 0.005>     define wooden texture { noise surface { ambient 0.2  diffuse 0.7  specular white, 0.5 microfacet Reitz 10 position_fn position_cylindrical position_scale 1  lookup_fn lookup_sawtooth octaves 1 turbulence 1 color_map( [0.0, 0.2, light_wood, light_wood] [0.2, 0.3, light_wood, median_wood] [0.3, 0.4, median_wood, light_wood] [0.4, 0.7, light_wood, light_wood] [0.7, 0.8, light_wood, median_wood] [0.8, 0.9, median_wood, light_wood] [0.9, 1.0, light_wood, dark_wood]) } } define glass texture { surface { ambient 0 diffuse 0 specular 0.2 reflection white, 0.1 transmission white, 1, 1.5 }} define shiny surface { ambient 0.1 diffuse 0.6 specular white, 0.6 microfacet Phong 7  } define steely_blue texture { shiny { color black } } define chrome texture { surface { color white ambient 0.0 diffuse 0.2 specular 0.4 microfacet Phong 10 reflection 0.8 } }   viewpoint {     from <4.000, -1.000, 1.000> at <0.000, 0.000, 0.000> up <0, 1, 0> angle 60     resolution 640, 480 aspect 1.6 image_format 0 }       light <-10, 30, 20> light <-10, 30, -20>   object { disc <0, -2, 0>, <0, 1, 0>, 30 wooden }   object { sphere <0.000, 0.000, 0.000>, 1.00 chrome } object { cylinder <0.000, 0.000, 0.000>, <0.000, 0.000, -4.000>, 0.50 chrome }   After setting up the background and defining colors and textures, the viewpoint is specified. The “camera” is located at a point in 3D space, and it looks towards another point. The angle, image resolution, and aspect ratio are specified. Two lights are present in the image at defined coordinates. The three objects in the image are a wooden disc to represent a table top, and a sphere and cylinder that intersect to form a pin that will be used for the pin board toy in the final animation. When the image is rendered, the following image is produced. The pins are modeled with a chrome surface, so they reflect the environment around them. Note that the scale of the pin shaft is not correct, this will be fixed later. Modeling the Pin Board The frame of the pin-board is made up of three boxes, and six cylinders, the front box is modeled using a clear, slightly reflective solid, with the same refractive index of glass. The other shapes are modeled as metal. object { box <-5.5, -1.5, 1>, <5.5, 5.5, 1.2> glass } object { box <-5.5, -1.5, -0.04>, <5.5, 5.5, -0.09> steely_blue } object { box <-5.5, -1.5, -0.52>, <5.5, 5.5, -0.59> steely_blue } object { cylinder <-5.2, -1.2, 1.4>, <-5.2, -1.2, -0.74>, 0.2 steely_blue } object { cylinder <5.2, -1.2, 1.4>, <5.2, -1.2, -0.74>, 0.2 steely_blue } object { cylinder <-5.2, 5.2, 1.4>, <-5.2, 5.2, -0.74>, 0.2 steely_blue } object { cylinder <5.2, 5.2, 1.4>, <5.2, 5.2, -0.74>, 0.2 steely_blue } object { cylinder <0, -1.2, 1.4>, <0, -1.2, -0.74>, 0.2 steely_blue } object { cylinder <0, 5.2, 1.4>, <0, 5.2, -0.74>, 0.2 steely_blue }   In order to create the matrix of pins that make up the pin board I used a basic console application with a few nested loops to create two intersecting matrixes of pins, which models the layout used in the pin boards. The resulting image is shown below. The pin board contains 11,481 pins, with the scene file containing 23,709 lines of code. For the complete animation 2,000 scene files will be created, which is over 47 million lines of code. Each pin in the pin-board will slide out a specific distance when an object is pressed into the back of the board. This is easily modeled by setting the Z coordinate of the pin to a specific value. In order to set all of the pins in the pin-board to the correct position, a bitmap image can be used. The position of the pin can be set based on the color of the pixel at the appropriate position in the image. When the Windows Azure logo is used to set the Z coordinate of the pins, the following image is generated. The challenge now was to make a cool animation. The Azure Logo is fine, but it is static. Using a normal video to animate the pins would not work; the colors in the video would not be the same as the depth of the objects from the camera. In order to simulate the pin board accurately a series of frames from a depth camera could be used. Windows Kinect The Kenect controllers for the X-Box 360 and Windows feature a depth camera. The Kinect SDK for Windows provides a programming interface for Kenect, providing easy access for .NET developers to the Kinect sensors. The Kinect Explorer provided with the Kinect SDK is a great starting point for exploring Kinect from a developers perspective. Both the X-Box 360 Kinect and the Windows Kinect will work with the Kinect SDK, the Windows Kinect is required for commercial applications, but the X-Box Kinect can be used for hobby projects. The Windows Kinect has the advantage of providing a mode to allow depth capture with objects closer to the camera, which makes for a more accurate depth image for setting the pin positions. Creating a Depth Field Animation The depth field animation used to set the positions of the pin in the pin board was created using a modified version of the Kinect Explorer sample application. In order to simulate the pin board accurately, a small section of the depth range from the depth sensor will be used. Any part of the object in front of the depth range will result in a white pixel; anything behind the depth range will be black. Within the depth range the pixels in the image will be set to RGB values from 0,0,0 to 255,255,255. A screen shot of the modified Kinect Explorer application is shown below. The Kinect Explorer sample application was modified to include slider controls that are used to set the depth range that forms the image from the depth stream. This allows the fine tuning of the depth image that is required for simulating the position of the pins in the pin board. The Kinect Explorer was also modified to record a series of images from the depth camera and save them as a sequence JPEG files that will be used to animate the pins in the animation the Start and Stop buttons are used to start and stop the image recording. En example of one of the depth images is shown below. Once a series of 2,000 depth images has been captured, the task of creating the animation can begin. Rendering a Test Frame In order to test the creation of frames and get an approximation of the time required to render each frame a test frame was rendered on-premise using PolyRay. The output of the rendering process is shown below. The test frame contained 23,629 primitive shapes, most of which are the spheres and cylinders that are used for the 11,800 or so pins in the pin board. The 1280x720 image contains 921,600 pixels, but as anti-aliasing was used the number of rays that were calculated was 4,235,777, with 3,478,754,073 object boundaries checked. The test frame of the pin board with the depth field image applied is shown below. The tracing time for the test frame was 4 minutes 27 seconds, which means rendering the2,000 frames in the animation would take over 148 hours, or a little over 6 days. Although this is much faster that an old 486, waiting almost a week to see the results of an animation would make it challenging for animators to create, view, and refine their animations. It would be much better if the animation could be rendered in less than one hour. Windows Azure Worker Roles The cost of creating an on-premise render farm to render animations increases in proportion to the number of servers. The table below shows the cost of servers for creating a render farm, assuming a cost of $500 per server. Number of Servers Cost 1 $500 16 $8,000 256 $128,000   As well as the cost of the servers, there would be additional costs for networking, racks etc. Hosting an environment of 256 servers on-premise would require a server room with cooling, and some pretty hefty power cabling. The Windows Azure compute services provide worker roles, which are ideal for performing processor intensive compute tasks. With the scalability available in Windows Azure a job that takes 256 hours to complete could be perfumed using different numbers of worker roles. The time and cost of using 1, 16 or 256 worker roles is shown below. Number of Worker Roles Render Time Cost 1 256 hours $30.72 16 16 hours $30.72 256 1 hour $30.72   Using worker roles in Windows Azure provides the same cost for the 256 hour job, irrespective of the number of worker roles used. Provided the compute task can be broken down into many small units, and the worker role compute power can be used effectively, it makes sense to scale the application so that the task is completed quickly, making the results available in a timely fashion. The task of rendering 2,000 frames in an animation is one that can easily be broken down into 2,000 individual pieces, which can be performed by a number of worker roles. Creating a Render Farm in Windows Azure The architecture of the render farm is shown in the following diagram. The render farm is a hybrid application with the following components: ·         On-Premise o   Windows Kinect – Used combined with the Kinect Explorer to create a stream of depth images. o   Animation Creator – This application uses the depth images from the Kinect sensor to create scene description files for PolyRay. These files are then uploaded to the jobs blob container, and job messages added to the jobs queue. o   Process Monitor – This application queries the role instance lifecycle table and displays statistics about the render farm environment and render process. o   Image Downloader – This application polls the image queue and downloads the rendered animation files once they are complete. ·         Windows Azure o   Azure Storage – Queues and blobs are used for the scene description files and completed frames. A table is used to store the statistics about the rendering environment.   The architecture of each worker role is shown below.   The worker role is configured to use local storage, which provides file storage on the worker role instance that can be use by the applications to render the image and transform the format of the image. The service definition for the worker role with the local storage configuration highlighted is shown below. <?xml version="1.0" encoding="utf-8"?> <ServiceDefinition name="CloudRay" >   <WorkerRole name="CloudRayWorkerRole" vmsize="Small">     <Imports>     </Imports>     <ConfigurationSettings>       <Setting name="DataConnectionString" />     </ConfigurationSettings>     <LocalResources>       <LocalStorage name="RayFolder" cleanOnRoleRecycle="true" />     </LocalResources>   </WorkerRole> </ServiceDefinition>     The two executable programs, PolyRay.exe and DTA.exe are included in the Azure project, with Copy Always set as the property. PolyRay will take the scene description file and render it to a Truevision TGA file. As the TGA format has not seen much use since the mid 90’s it is converted to a JPG image using Dave's Targa Animator, another shareware application from the 90’s. Each worker roll will use the following process to render the animation frames. 1.       The worker process polls the job queue, if a job is available the scene description file is downloaded from blob storage to local storage. 2.       PolyRay.exe is started in a process with the appropriate command line arguments to render the image as a TGA file. 3.       DTA.exe is started in a process with the appropriate command line arguments convert the TGA file to a JPG file. 4.       The JPG file is uploaded from local storage to the images blob container. 5.       A message is placed on the images queue to indicate a new image is available for download. 6.       The job message is deleted from the job queue. 7.       The role instance lifecycle table is updated with statistics on the number of frames rendered by the worker role instance, and the CPU time used. The code for this is shown below. public override void Run() {     // Set environment variables     string polyRayPath = Path.Combine(Environment.GetEnvironmentVariable("RoleRoot"), PolyRayLocation);     string dtaPath = Path.Combine(Environment.GetEnvironmentVariable("RoleRoot"), DTALocation);       LocalResource rayStorage = RoleEnvironment.GetLocalResource("RayFolder");     string localStorageRootPath = rayStorage.RootPath;       JobQueue jobQueue = new JobQueue("renderjobs");     JobQueue downloadQueue = new JobQueue("renderimagedownloadjobs");     CloudRayBlob sceneBlob = new CloudRayBlob("scenes");     CloudRayBlob imageBlob = new CloudRayBlob("images");     RoleLifecycleDataSource roleLifecycleDataSource = new RoleLifecycleDataSource();       Frames = 0;       while (true)     {         // Get the render job from the queue         CloudQueueMessage jobMsg = jobQueue.Get();           if (jobMsg != null)         {             // Get the file details             string sceneFile = jobMsg.AsString;             string tgaFile = sceneFile.Replace(".pi", ".tga");             string jpgFile = sceneFile.Replace(".pi", ".jpg");               string sceneFilePath = Path.Combine(localStorageRootPath, sceneFile);             string tgaFilePath = Path.Combine(localStorageRootPath, tgaFile);             string jpgFilePath = Path.Combine(localStorageRootPath, jpgFile);               // Copy the scene file to local storage             sceneBlob.DownloadFile(sceneFilePath);               // Run the ray tracer.             string polyrayArguments =                 string.Format("\"{0}\" -o \"{1}\" -a 2", sceneFilePath, tgaFilePath);             Process polyRayProcess = new Process();             polyRayProcess.StartInfo.FileName =                 Path.Combine(Environment.GetEnvironmentVariable("RoleRoot"), polyRayPath);             polyRayProcess.StartInfo.Arguments = polyrayArguments;             polyRayProcess.Start();             polyRayProcess.WaitForExit();               // Convert the image             string dtaArguments =                 string.Format(" {0} /FJ /P{1}", tgaFilePath, Path.GetDirectoryName (jpgFilePath));             Process dtaProcess = new Process();             dtaProcess.StartInfo.FileName =                 Path.Combine(Environment.GetEnvironmentVariable("RoleRoot"), dtaPath);             dtaProcess.StartInfo.Arguments = dtaArguments;             dtaProcess.Start();             dtaProcess.WaitForExit();               // Upload the image to blob storage             imageBlob.UploadFile(jpgFilePath);               // Add a download job.             downloadQueue.Add(jpgFile);               // Delete the render job message             jobQueue.Delete(jobMsg);               Frames++;         }         else         {             Thread.Sleep(1000);         }           // Log the worker role activity.         roleLifecycleDataSource.Alive             ("CloudRayWorker", RoleLifecycleDataSource.RoleLifecycleId, Frames);     } }     Monitoring Worker Role Instance Lifecycle In order to get more accurate statistics about the lifecycle of the worker role instances used to render the animation data was tracked in an Azure storage table. The following class was used to track the worker role lifecycles in Azure storage.   public class RoleLifecycle : TableServiceEntity {     public string ServerName { get; set; }     public string Status { get; set; }     public DateTime StartTime { get; set; }     public DateTime EndTime { get; set; }     public long SecondsRunning { get; set; }     public DateTime LastActiveTime { get; set; }     public int Frames { get; set; }     public string Comment { get; set; }       public RoleLifecycle()     {     }       public RoleLifecycle(string roleName)     {         PartitionKey = roleName;         RowKey = Utils.GetAscendingRowKey();         Status = "Started";         StartTime = DateTime.UtcNow;         LastActiveTime = StartTime;         EndTime = StartTime;         SecondsRunning = 0;         Frames = 0;     } }     A new instance of this class is created and added to the storage table when the role starts. It is then updated each time the worker renders a frame to record the total number of frames rendered and the total processing time. These statistics are used be the monitoring application to determine the effectiveness of use of resources in the render farm. Rendering the Animation The Azure solution was deployed to Windows Azure with the service configuration set to 16 worker role instances. This allows for the application to be tested in the cloud environment, and the performance of the application determined. When I demo the application at conferences and user groups I often start with 16 instances, and then scale up the application to the full 256 instances. The configuration to run 16 instances is shown below. <?xml version="1.0" encoding="utf-8"?> <ServiceConfiguration serviceName="CloudRay" xmlns="http://schemas.microsoft.com/ServiceHosting/2008/10/ServiceConfiguration" osFamily="1" osVersion="*">   <Role name="CloudRayWorkerRole">     <Instances count="16" />     <ConfigurationSettings>       <Setting name="DataConnectionString"         value="DefaultEndpointsProtocol=https;AccountName=cloudraydata;AccountKey=..." />     </ConfigurationSettings>   </Role> </ServiceConfiguration>     About six minutes after deploying the application the first worker roles become active and start to render the first frames of the animation. The CloudRay Monitor application displays an icon for each worker role instance, with a number indicating the number of frames that the worker role has rendered. The statistics on the left show the number of active worker roles and statistics about the render process. The render time is the time since the first worker role became active; the CPU time is the total amount of processing time used by all worker role instances to render the frames.   Five minutes after the first worker role became active the last of the 16 worker roles activated. By this time the first seven worker roles had each rendered one frame of the animation.   With 16 worker roles u and running it can be seen that one hour and 45 minutes CPU time has been used to render 32 frames with a render time of just under 10 minutes.     At this rate it would take over 10 hours to render the 2,000 frames of the full animation. In order to complete the animation in under an hour more processing power will be required. Scaling the render farm from 16 instances to 256 instances is easy using the new management portal. The slider is set to 256 instances, and the configuration saved. We do not need to re-deploy the application, and the 16 instances that are up and running will not be affected. Alternatively, the configuration file for the Azure service could be modified to specify 256 instances.   <?xml version="1.0" encoding="utf-8"?> <ServiceConfiguration serviceName="CloudRay" xmlns="http://schemas.microsoft.com/ServiceHosting/2008/10/ServiceConfiguration" osFamily="1" osVersion="*">   <Role name="CloudRayWorkerRole">     <Instances count="256" />     <ConfigurationSettings>       <Setting name="DataConnectionString"         value="DefaultEndpointsProtocol=https;AccountName=cloudraydata;AccountKey=..." />     </ConfigurationSettings>   </Role> </ServiceConfiguration>     Six minutes after the new configuration has been applied 75 new worker roles have activated and are processing their first frames.   Five minutes later the full configuration of 256 worker roles is up and running. We can see that the average rate of frame rendering has increased from 3 to 12 frames per minute, and that over 17 hours of CPU time has been utilized in 23 minutes. In this test the time to provision 140 worker roles was about 11 minutes, which works out at about one every five seconds.   We are now half way through the rendering, with 1,000 frames complete. This has utilized just under three days of CPU time in a little over 35 minutes.   The animation is now complete, with 2,000 frames rendered in a little over 52 minutes. The CPU time used by the 256 worker roles is 6 days, 7 hours and 22 minutes with an average frame rate of 38 frames per minute. The rendering of the last 1,000 frames took 16 minutes 27 seconds, which works out at a rendering rate of 60 frames per minute. The frame counts in the server instances indicate that the use of a queue to distribute the workload has been very effective in distributing the load across the 256 worker role instances. The first 16 instances that were deployed first have rendered between 11 and 13 frames each, whilst the 240 instances that were added when the application was scaled have rendered between 6 and 9 frames each.   Completed Animation I’ve uploaded the completed animation to YouTube, a low resolution preview is shown below. Pin Board Animation Created using Windows Kinect and 256 Windows Azure Worker Roles   The animation can be viewed in 1280x720 resolution at the following link: http://www.youtube.com/watch?v=n5jy6bvSxWc Effective Use of Resources According to the CloudRay monitor statistics the animation took 6 days, 7 hours and 22 minutes CPU to render, this works out at 152 hours of compute time, rounded up to the nearest hour. As the usage for the worker role instances are billed for the full hour, it may have been possible to render the animation using fewer than 256 worker roles. When deciding the optimal usage of resources, the time required to provision and start the worker roles must also be considered. In the demo I started with 16 worker roles, and then scaled the application to 256 worker roles. It would have been more optimal to start the application with maybe 200 worker roles, and utilized the full hour that I was being billed for. This would, however, have prevented showing the ease of scalability of the application. The new management portal displays the CPU usage across the worker roles in the deployment. The average CPU usage across all instances is 93.27%, with over 99% used when all the instances are up and running. This shows that the worker role resources are being used very effectively. Grid Computing Scenarios Although I am using this scenario for a hobby project, there are many scenarios where a large amount of compute power is required for a short period of time. Windows Azure provides a great platform for developing these types of grid computing applications, and can work out very cost effective. ·         Windows Azure can provide massive compute power, on demand, in a matter of minutes. ·         The use of queues to manage the load balancing of jobs between role instances is a simple and effective solution. ·         Using a cloud-computing platform like Windows Azure allows proof-of-concept scenarios to be tested and evaluated on a very low budget. ·         No charges for inbound data transfer makes the uploading of large data sets to Windows Azure Storage services cost effective. (Transaction charges still apply.) Tips for using Windows Azure for Grid Computing Scenarios I found the implementation of a render farm using Windows Azure a fairly simple scenario to implement. I was impressed by ease of scalability that Azure provides, and by the short time that the application took to scale from 16 to 256 worker role instances. In this case it was around 13 minutes, in other tests it took between 10 and 20 minutes. The following tips may be useful when implementing a grid computing project in Windows Azure. ·         Using an Azure Storage queue to load-balance the units of work across multiple worker roles is simple and very effective. The design I have used in this scenario could easily scale to many thousands of worker role instances. ·         Windows Azure accounts are typically limited to 20 cores. If you need to use more than this, a call to support and a credit card check will be required. ·         Be aware of how the billing model works. You will be charged for worker role instances for the full clock our in which the instance is deployed. Schedule the workload to start just after the clock hour has started. ·         Monitor the utilization of the resources you are provisioning, ensure that you are not paying for worker roles that are idle. ·         If you are deploying third party applications to worker roles, you may well run into licensing issues. Purchasing software licenses on a per-processor basis when using hundreds of processors for a short time period would not be cost effective. ·         Third party software may also require installation onto the worker roles, which can be accomplished using start-up tasks. Bear in mind that adding a startup task and possible re-boot will add to the time required for the worker role instance to start and activate. An alternative may be to use a prepared VM and use VM roles. ·         Consider using the Windows Azure Autoscaling Application Block (WASABi) to autoscale the worker roles in your application. When using a large number of worker roles, the utilization must be carefully monitored, if the scaling algorithms are not optimal it could get very expensive!

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  • C# async and actors

    - by Alex.Davies
    If you read my last post about async, you might be wondering what drove me to write such odd code in the first place. The short answer is that .NET Demon is written using NAct Actors. Actors are an old idea, which I believe deserve a renaissance under C# 5. The idea is to isolate each stateful object so that only one thread has access to its state at any point in time. That much should be familiar, it's equivalent to traditional lock-based synchronization. The different part is that actors pass "messages" to each other rather than calling a method and waiting for it to return. By doing that, each thread can only ever be holding one lock. This completely eliminates deadlocks, my least favourite concurrency problem. Most people who use actors take this quite literally, and there are plenty of frameworks which help you to create message classes and loops which can receive the messages, inspect what type of message they are, and process them accordingly. But I write C# for a reason. Do I really have to choose between using actors and everything I love about object orientation in C#? Type safety Interfaces Inheritance Generics As it turns out, no. You don't need to choose between messages and method calls. A method call makes a perfectly good message, as long as you don't wait for it to return. This is where asynchonous methods come in. I have used NAct for a while to wrap my objects in a proxy layer. As long as I followed the rule that methods must always return void, NAct queued up the call for later, and immediately released my thread. When I needed to get information out of other actors, I could use EventHandlers and callbacks (continuation passing style, for any CS geeks reading), and NAct would call me back in my isolated thread without blocking the actor that raised the event. Using callbacks looks horrible though. To remind you: m_BuildControl.FilterEnabledForBuilding(    projects,    enabledProjects = m_OutOfDateProjectFinder.FilterNeedsBuilding(        enabledProjects,             newDirtyProjects =             {                 ....... Which is why I'm really happy that NAct now supports async methods. Now, methods are allowed to return Task rather than just void. I can await those methods, and C# 5 will turn the rest of my method into a continuation for me. NAct will run the other method in the other actor's context, but will make sure that when my method resumes, we're back in my context. Neither actor was ever blocked waiting for the other one. Apart from when they were actually busy doing something, they were responsive to concurrent messages from other sources. To be fair, you could use async methods with lock statements to achieve exactly the same thing, but it's ugly. Here's a realistic example of an object that has a queue of data that gets passed to another object to be processed: class QueueProcessor {    private readonly ItemProcessor m_ItemProcessor = ...     private readonly object m_Sync = new object();    private Queue<object> m_DataQueue = ...    private List<object> m_Results = ...     public async Task ProcessOne() {         object data = null;         lock (m_Sync)         {             data = m_DataQueue.Dequeue();         }         var processedData = await m_ItemProcessor.ProcessData(data); lock (m_Sync)         {             m_Results.Add(processedData);         }     } } We needed to write two lock blocks, one to get the data to process, one to store the result. The worrying part is how easily we could have forgotten one of the locks. Compare that to the version using NAct: class QueueProcessorActor : IActor { private readonly ItemProcessor m_ItemProcessor = ... private Queue<object> m_DataQueue = ... private List<object> m_Results = ... public async Task ProcessOne()     {         // We are an actor, it's always thread-safe to access our private fields         var data = m_DataQueue.Dequeue();         var processedData = await m_ItemProcessor.ProcessData(data);         m_Results.Add(processedData);     } } You don't have to explicitly lock anywhere, NAct ensures that your code will only ever run on one thread, because it's an actor. Either way, async is definitely better than traditional synchronous code. Here's a diagram of what a typical synchronous implementation might do: The left side shows what is running on the thread that has the lock required to access the QueueProcessor's data. The red section is where that lock is held, but doesn't need to be. Contrast that with the async version we wrote above: Here, the lock is released in the middle. The QueueProcessor is free to do something else. Most importantly, even if the ItemProcessor sometimes calls the QueueProcessor, they can never deadlock waiting for each other. So I thoroughly recommend you use async for all code that has to wait a while for things. And if you find yourself writing lots of lock statements, think about using actors as well. Using actors and async together really takes the misery out of concurrent programming.

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