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  • Common filesystem for servers behind a rackspace load balancer

    - by thanos panousis
    Our PHP application consists of a single web server that will receive files from clients and perform a CPU-intensive analysis on them. Right now, analysis of a single user upload can take 3sec to conclude and take 100% CPU. This makes our system capacity amount to 1/3 requests per second. My team's requirement is to increase capacity without a lot of code reengineering. A possible solution would be to set up a load balancer in front of multiple servers running the same app, connecting to a common DB. The problem is that the analysis outputs files on disk. A load balancer would increase capacity, but then files won't be available between servers so consequent client requests may fail. We are hosted on Rackspace, is there a way to configure some sort of "common" storage for all servers, without having to rewrite our file persistance code? Current code relies on simple fopens etc. What are our options?

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  • PostgreSQL 9.0 HA load balancing between servers

    - by Vijay Ramachandran
    Hey folks, I'm bashing my head to configure load balancing stuff between two database servers. I have no clue whether, I can find any mechanism to implement this. I already tried to implement Heart beat clustering but it requires virtual Ip wherein I can't create virtual IP or assign my own IP address in amazon EC2. Is there a way to configure PostgreSQL database servers in similar to Amazon load balancing kind of thing ? If so, please suggest the solution. Thanks in advance.

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  • PHP and load balancing

    - by StCee
    I have one major domain but the server spec behind it is not good enough. Hence I want to relay the traffic, in particular php-mysql queries to multiple smaller servers. How is that normally be done? (BTW I wonder how much traffic or number of php/mysql request a normal setup on ec2 micro instance can handle? ) I did have a look of EC2 load balancer. But is it only possible to load balance on machines of your own account?

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  • Load balanced proxies to avoid an API request limit

    - by ClickClickClick
    There is a certain API out there which limits the number of requests per day per IP. My plan is to create a bunch of EC2 instances with elastic IPs to sidestep the limitation. I'm familiar with EC2 and am just interested in the configuration of the proxies and a software load balancer. I think I want to run a simple TCP Proxy on each instance and a software load balancer on the machine I will be requesting from. Something that allows the following to return a response from a different IP (round robin, availability, doesn't really matter..) eg. curl http://www.bbc.co.uk -x http://myproxyloadbalancer:port Could anyone recommend a combination of software or even a link to an article that details a pleasing way to pull it off? (My client won't be curl but is proxy aware.. I'll be making the requests from a Ruby script..)

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  • Bundler isn't loading gems

    - by Garrett
    I have been having a problem with using Bundler and being able to access my gems without having to require them somewhere, as config.gem used to do that for me (as far as I know). In my Rails 3 app, I defined my Gemfile like so: clear_sources source "http://gemcutter.org" source "http://gems.github.com" bundle_path "vendor/bundler_gems" ## Bundle edge rails: git "git://github.com/rails/arel.git" git "git://github.com/rails/rack.git" gem "rails", :git => "git://github.com/rails/rails.git" ## Bundle gem "mongo_mapper", :git => "git://github.com/jnunemaker/mongomapper.git" gem "bluecloth", ">= 2.0.0" Then I run gem bundle, it bundles it all up like expected. Inside the environment.rb file that is included within boot.rb it looks like this: # DO NOT MODIFY THIS FILE module Bundler file = File.expand_path(__FILE__) dir = File.dirname(file) ENV["PATH"] = "#{dir}/../../../../bin:#{ENV["PATH"]}" ENV["RUBYOPT"] = "-r#{file} #{ENV["RUBYOPT"]}" $LOAD_PATH.unshift File.expand_path("#{dir}/gems/builder-2.1.2/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/builder-2.1.2/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/text-hyphen-1.0.0/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/text-hyphen-1.0.0/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/i18n-0.3.3/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/i18n-0.3.3/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/arel/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/arel/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/activemodel/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/activemodel/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/jnunemaker-validatable-1.8.1/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/jnunemaker-validatable-1.8.1/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/abstract-1.0.0/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/abstract-1.0.0/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/erubis-2.6.5/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/erubis-2.6.5/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/mime-types-1.16/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/mime-types-1.16/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/mail-2.1.2/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/mail-2.1.2/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/rake-0.8.7/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/rake-0.8.7/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/railties/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/railties/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/memcache-client-1.7.7/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/memcache-client-1.7.7/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rack/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rack/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/rack-test-0.5.3/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/rack-test-0.5.3/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/rack-mount-0.4.5/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/rack-mount-0.4.5/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/actionpack/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/actionpack/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/bluecloth-2.0.7/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/bluecloth-2.0.7/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/bluecloth-2.0.7/ext") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/activerecord/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/activerecord/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/text-format-1.0.0/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/text-format-1.0.0/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/actionmailer/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/actionmailer/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/tzinfo-0.3.16/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/tzinfo-0.3.16/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/activesupport/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/activesupport/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/activeresource/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/activeresource/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/rails/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/mongo-0.18.2/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/gems/mongo-0.18.2/lib") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/mongomapper/bin") $LOAD_PATH.unshift File.expand_path("#{dir}/dirs/mongomapper/lib") @gemfile = "#{dir}/../../../../Gemfile" require "rubygems" unless respond_to?(:gem) # 1.9 already has RubyGems loaded @bundled_specs = {} @bundled_specs["builder"] = eval(File.read("#{dir}/specifications/builder-2.1.2.gemspec")) @bundled_specs["builder"].loaded_from = "#{dir}/specifications/builder-2.1.2.gemspec" @bundled_specs["text-hyphen"] = eval(File.read("#{dir}/specifications/text-hyphen-1.0.0.gemspec")) @bundled_specs["text-hyphen"].loaded_from = "#{dir}/specifications/text-hyphen-1.0.0.gemspec" @bundled_specs["i18n"] = eval(File.read("#{dir}/specifications/i18n-0.3.3.gemspec")) @bundled_specs["i18n"].loaded_from = "#{dir}/specifications/i18n-0.3.3.gemspec" @bundled_specs["arel"] = eval(File.read("#{dir}/specifications/arel-0.2.pre.gemspec")) @bundled_specs["arel"].loaded_from = "#{dir}/specifications/arel-0.2.pre.gemspec" @bundled_specs["activemodel"] = eval(File.read("#{dir}/specifications/activemodel-3.0.pre.gemspec")) @bundled_specs["activemodel"].loaded_from = "#{dir}/specifications/activemodel-3.0.pre.gemspec" @bundled_specs["jnunemaker-validatable"] = eval(File.read("#{dir}/specifications/jnunemaker-validatable-1.8.1.gemspec")) @bundled_specs["jnunemaker-validatable"].loaded_from = "#{dir}/specifications/jnunemaker-validatable-1.8.1.gemspec" @bundled_specs["abstract"] = eval(File.read("#{dir}/specifications/abstract-1.0.0.gemspec")) @bundled_specs["abstract"].loaded_from = "#{dir}/specifications/abstract-1.0.0.gemspec" @bundled_specs["erubis"] = eval(File.read("#{dir}/specifications/erubis-2.6.5.gemspec")) @bundled_specs["erubis"].loaded_from = "#{dir}/specifications/erubis-2.6.5.gemspec" @bundled_specs["mime-types"] = eval(File.read("#{dir}/specifications/mime-types-1.16.gemspec")) @bundled_specs["mime-types"].loaded_from = "#{dir}/specifications/mime-types-1.16.gemspec" @bundled_specs["mail"] = eval(File.read("#{dir}/specifications/mail-2.1.2.gemspec")) @bundled_specs["mail"].loaded_from = "#{dir}/specifications/mail-2.1.2.gemspec" @bundled_specs["rake"] = eval(File.read("#{dir}/specifications/rake-0.8.7.gemspec")) @bundled_specs["rake"].loaded_from = "#{dir}/specifications/rake-0.8.7.gemspec" @bundled_specs["railties"] = eval(File.read("#{dir}/specifications/railties-3.0.pre.gemspec")) @bundled_specs["railties"].loaded_from = "#{dir}/specifications/railties-3.0.pre.gemspec" @bundled_specs["memcache-client"] = eval(File.read("#{dir}/specifications/memcache-client-1.7.7.gemspec")) @bundled_specs["memcache-client"].loaded_from = "#{dir}/specifications/memcache-client-1.7.7.gemspec" @bundled_specs["rack"] = eval(File.read("#{dir}/specifications/rack-1.1.0.gemspec")) @bundled_specs["rack"].loaded_from = "#{dir}/specifications/rack-1.1.0.gemspec" @bundled_specs["rack-test"] = eval(File.read("#{dir}/specifications/rack-test-0.5.3.gemspec")) @bundled_specs["rack-test"].loaded_from = "#{dir}/specifications/rack-test-0.5.3.gemspec" @bundled_specs["rack-mount"] = eval(File.read("#{dir}/specifications/rack-mount-0.4.5.gemspec")) @bundled_specs["rack-mount"].loaded_from = "#{dir}/specifications/rack-mount-0.4.5.gemspec" @bundled_specs["actionpack"] = eval(File.read("#{dir}/specifications/actionpack-3.0.pre.gemspec")) @bundled_specs["actionpack"].loaded_from = "#{dir}/specifications/actionpack-3.0.pre.gemspec" @bundled_specs["bluecloth"] = eval(File.read("#{dir}/specifications/bluecloth-2.0.7.gemspec")) @bundled_specs["bluecloth"].loaded_from = "#{dir}/specifications/bluecloth-2.0.7.gemspec" @bundled_specs["activerecord"] = eval(File.read("#{dir}/specifications/activerecord-3.0.pre.gemspec")) @bundled_specs["activerecord"].loaded_from = "#{dir}/specifications/activerecord-3.0.pre.gemspec" @bundled_specs["text-format"] = eval(File.read("#{dir}/specifications/text-format-1.0.0.gemspec")) @bundled_specs["text-format"].loaded_from = "#{dir}/specifications/text-format-1.0.0.gemspec" @bundled_specs["actionmailer"] = eval(File.read("#{dir}/specifications/actionmailer-3.0.pre.gemspec")) @bundled_specs["actionmailer"].loaded_from = "#{dir}/specifications/actionmailer-3.0.pre.gemspec" @bundled_specs["tzinfo"] = eval(File.read("#{dir}/specifications/tzinfo-0.3.16.gemspec")) @bundled_specs["tzinfo"].loaded_from = "#{dir}/specifications/tzinfo-0.3.16.gemspec" @bundled_specs["activesupport"] = eval(File.read("#{dir}/specifications/activesupport-3.0.pre.gemspec")) @bundled_specs["activesupport"].loaded_from = "#{dir}/specifications/activesupport-3.0.pre.gemspec" @bundled_specs["activeresource"] = eval(File.read("#{dir}/specifications/activeresource-3.0.pre.gemspec")) @bundled_specs["activeresource"].loaded_from = "#{dir}/specifications/activeresource-3.0.pre.gemspec" @bundled_specs["rails"] = eval(File.read("#{dir}/specifications/rails-3.0.pre.gemspec")) @bundled_specs["rails"].loaded_from = "#{dir}/specifications/rails-3.0.pre.gemspec" @bundled_specs["mongo"] = eval(File.read("#{dir}/specifications/mongo-0.18.2.gemspec")) @bundled_specs["mongo"].loaded_from = "#{dir}/specifications/mongo-0.18.2.gemspec" @bundled_specs["mongo_mapper"] = eval(File.read("#{dir}/specifications/mongo_mapper-0.6.10.gemspec")) @bundled_specs["mongo_mapper"].loaded_from = "#{dir}/specifications/mongo_mapper-0.6.10.gemspec" def self.add_specs_to_loaded_specs Gem.loaded_specs.merge! @bundled_specs end def self.add_specs_to_index @bundled_specs.each do |name, spec| Gem.source_index.add_spec spec end end add_specs_to_loaded_specs add_specs_to_index def self.require_env(env = nil) context = Class.new do def initialize(env) @env = env && env.to_s ; end def method_missing(*) ; yield if block_given? ; end def only(*env) old, @only = @only, _combine_only(env.flatten) yield @only = old end def except(*env) old, @except = @except, _combine_except(env.flatten) yield @except = old end def gem(name, *args) opt = args.last.is_a?(Hash) ? args.pop : {} only = _combine_only(opt[:only] || opt["only"]) except = _combine_except(opt[:except] || opt["except"]) files = opt[:require_as] || opt["require_as"] || name files = [files] unless files.respond_to?(:each) return unless !only || only.any? {|e| e == @env } return if except && except.any? {|e| e == @env } if files = opt[:require_as] || opt["require_as"] files = Array(files) files.each { |f| require f } else begin require name rescue LoadError # Do nothing end end yield if block_given? true end private def _combine_only(only) return @only unless only only = [only].flatten.compact.uniq.map { |o| o.to_s } only &= @only if @only only end def _combine_except(except) return @except unless except except = [except].flatten.compact.uniq.map { |o| o.to_s } except |= @except if @except except end end context.new(env && env.to_s).instance_eval(File.read(@gemfile), @gemfile, 1) end end module Gem @loaded_stacks = Hash.new { |h,k| h[k] = [] } def source_index.refresh! super Bundler.add_specs_to_index end end But when I try to access any of my gems, e.g. MongoMapper, Paperclip, Haml, etc. I get: NameError: uninitialized constant MongoMapper The same goes for any other gem. Does Bundler not include gems like the old Rails 2.0 did? Or is something messed up with my system? Any help would be appreciated, thank you!

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  • A question about the order of pagination

    - by SpawnCxy
    Currently I'm deal with a history message page using Cakephp.And I got a problem about records' order.In the controller,codes about pagination as follows $this->paginate['Msg'] = array('order'=>'Msg.created desc'); $msgs = $this->paginate('Msg'); $this->set('historymsgs',$msgs); Then I got a page of messges like this: tom:I'm eighteen. Jerry:How old are you? tom:Tom. Jerry:what's your name? tom:Hi nice to meet you too! Jerry:Hello,nice to meet you! But what I need is the reversed order of the messages.How can I append a condition of Msg.created asc here? Thanks in advance.

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  • "SELECT TOP", "LEFT OUTER JOIN", "ORDER BY" gives extra rows

    - by Codesleuth
    I have the following Access query I'm running through OLE DB in .NET: SELECT TOP 25 tblClient.ClientCode, tblRegion.Region FROM (tblClient LEFT OUTER JOIN tblRegion ON tblClient.RegionCode = tblRegion.RegionCode) ORDER BY tblRegion.Region There are 431 records within tblClient that have RegionCode set to NULL. For some reason, the query above returns all these 431 records instead of the first 25. If I change the query to ORDER BY tblClient.Client (the name of the client) like so: SELECT TOP 25 tblClient.ClientCode, tblRegion.Region FROM (tblClient LEFT OUTER JOIN tblRegion ON tblClient.RegionCode = tblRegion.RegionCode) ORDER BY tblClient.Client I get the expected result set of 25 records, showing a mixture of region names and NULL values. Why is it that ordering by a field retrieved through a LEFT OUTER JOIN will the TOP clause not work?

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  • Order By Rand by Time (HQL)

    - by Felipe
    Hi all, I'm developing a web application using asp.net Mvc 2 and NHibernate, and I'm paging data (products in a category) in my page, but this data are random, so, I'm using a HQL statement link this: string hql = "from Product p where p.Category.Id=:IdCategory order by rand()"; It's working fine, but when I page, sometimes the same product appears in the first, second, etc... pages because it's order by rand(). Is there any way to make a random order by fixed by period (time internal) ? Or any solution ? thanks Cheers

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  • Rail 3 custom renderer: where do put this code?

    - by Derick Bailey
    I'm following along with Yehuda's example on how to build a custom renderer for Rails 3, according to this post: http://www.engineyard.com/blog/2010/render-options-in-rails-3/ I've got my code working, but I'm having a hard time figuring out where this code should live. Right now, I've got my code stuck right inside of my controller file. Doing this, everything works. When I move the code to the lib folder, though, I have explicitly 'require' my file in the controller that needs the renderer or it won't work. Yes, the file gets loaded when it sits in the lib folder, automatically. but the code to add the renderer isn't working for some reason, until I do a require on it. where should I put my code to add the renderer and mime type, so that rails 3 will pick it up and register it for me, without me having to manually require the file in my controller?

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  • Return order of MySQL SHOW COLUMNS

    - by rich
    Hey guys. Simple one this, but one I can't seem to find any information on so here goes. I need to find the columns in a specific table, which is no problem.... SHOW COLUMNS FROM tablename LIKE '%ColumnPrefix%'; But I need to know what order they will be returned, preferable by choosing to order the results ascending alphabetically. I have had no luck with using ORDER BY Field. Any ideas? Cheers!

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  • Override Devise Sign-in with reCaptcha

    - by Bashar Abdullah
    I'm trying to override the Rails devise login to include recaptcha. I followed the steps here http://presentations.royvandewater.com/authentication-with-devise.html#8 however for some reason, authentication always fails. To isolate the problem, I removed all my code and called super directly class SessionsController < Devise::SessionsController def create super end end file is at: Rails.root/app/controllers/sessions_controller.rb the slide suggest Rails.root/app/controllers/sessions.rb but I assume that was just a mistake. Trying it out didn't help either. I even copied the full Sessions Controller code into my own, still gives the problem. Authentication fails here specifically: resource = warden.authenticate!(:scope => resource_name, :recall => "#{controller_path}#new") Any idea what I might be doing wrong?

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  • SQL Simple ORDER BY

    - by AeroDroid
    I'm new to SQL and I don't think this question should be hard to answer. I have a high-score table for a game that contains the columns name, score, and rank. I want to know how I can order the table by descending order each time a new score is added so the table can always stay ordered by score. I know this is the wrong way of doing this, but I hope this makes my point kind of clearer. UPDATE `HSTable`.`Highscores` ORDER BY `Highscores`.`score` DESC; What is the correct way of approaching this? One more thing, is there a way I can set it so that the ranking value always stays where it's suppose to be from the SQL, for example, 1st place is always at the top regardless the score? Thanks!

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  • Can't connect to Sunspot server in Ubuntu server

    - by Chris Benseler
    I followed the steps in https://github.com/outoftime/sunspot/wiki/Adding-Sunspot-search-to-Rails-in-5-minutes-or-less to install & set up Sunspot search in Rails in a Mac OS and it is ok. In a Ubuntu server, there's connection refused error. When I run rake sunspot:solr:start and the proccess starts. The file sunspot-solr-development.pid is created in /tmp/pids But when I try to reindex rake sunspot:reindex ... rake aborted! Connection refused - connect(2) I tried to run the commands with sudo and gave permission 777 to the project files, but there's still error. Rails 3.0.8 Don't know where else to search for a solution...

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  • MySQL order by error in PHP

    - by theflyinghaiwian
    Hi, I'm making a simple cms system for a site I'm making for non-tech users to edit... So far so good but when I try and run this code I keep getting: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''pages' ORDER BY 'pages'.'pageOrder' ASC LIMIT 0 , 30' at line 1 By the error it looks like a problem with the order by section and indeed it works without it... $sql = "SELECT * FROM 'pages' ORDER BY 'pages'.'pageOrder' ASC LIMIT 0 , 30"; $result = mysql_query($sql) or die(mysql_error()); Now I know there is nothing wrong with the code because originally I wrote my own SQL but then after it failed I robbed some from phpmyadmin and it still gives the error but it works in phpmyadmin... I'm really at my wits end with this, help is very much appreciated thank you...

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  • Load Ruby on Rails models without loading the entire framework

    - by epochwolf
    I'm looking to create a custom daemon that will run various database tasks such as delaying mailings and user notifications (each notice is a separate row in the notifications table). I don't want to use script/runner or rake to do these tasks because it is possible that some of the tasks only require the create of one or two database rows or thousands of rows depending on the task. I don't want the overhead of launching a ruby process or loading the entire rails framework for each operation. I plan to keep this daemon in memory full time. To create this daemon I would like to use my models from my ruby on rails application. I have a number of rails plugins such as acts_as_tree and AASM that I will need loaded if I where to use the models. Some of the plugins I need to load are custom hacks on ActiveRecord::Base that I've created. (I am willing to accept removing or recoding some of the plugins if they need components from other parts of rails.) My questions are Is this a good idea? And - Is this possible to do in a way that doesn't have me manually including each file in my models and plugins? If not a good idea What is a good alternative? (I am not apposed to doing writing my own SQL queries but I would have to add database constraints and a separate user for the daemon to prevent any stupid accidents. Given my lack of familiarity with configuring a database, I would like to use active record as a crutch.)

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  • Ruby on Rails (Redmine) on Apache - 503 Error

    - by andrewtweber
    I am running a Ruby on Rails application called Redmine. It's been working fine, but today it's giving a 503 Service Temporarily Unavailable error. (It was initially set up by an employee who is now gone.) I check the error log and it says: [Mon Nov 21 11:03:30 2011] [error] (111)Connection refused: proxy: HTTP: attempt to connect to 127.0.0.1:3000 (127.0.0.1) failed [Mon Nov 21 11:03:30 2011] [error] ap_proxy_connect_backend disabling worker for (127.0.0.1) Here's a chunk of my Apache config <VirtualHost *:80> ServerName redmine.{domain}.com RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f RewriteRule ^/(.*)$ balancer://redminecluster%{REQUEST_URI} [P,QSA,L] </VirtualHost> <Proxy balancer://redminecluster> BalancerMember http://127.0.0.1:3000 </Proxy> I found this link: http://www.redmine.org/boards/2/topics/20561 which suggests I simply need to "start the redmine server." I've tried /etc/init.d/redmine start which gives me this output => Booting Mongrel => Rails 2.3.11 application starting on http://0.0.0.0:3000 The contents of /etc/init.d/redmine: cd /var/redmine sudo ruby script/server -d -e production One thing I immediately notice is that it says 0.0.0.0 instead of 127.0.0.1. In addition, running top or ps -ef shows no record of a "mongrel" or "redmine" process. I've also tried restarting Apache before and after starting redmine. Not sure where to go from here.

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  • Why doesn't jquery .load() load a text file from an external website?

    - by Edward Tanguay
    In the example below, when I click the button, it says "Load was performed" but no text is shown. I have a clientaccesspolicy.xml in the root directory and am able to asynchronously load the same file from silverlight. So I would think I should be able to access from AJAX as well. What do I have to change so that the text of the file http://www.tanguay.info/knowsite/data.txt is properly displayed in the #content element? <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <script type="text/javascript" src="http://www.google.com/jsapi"></script> <script type="text/javascript"> google.load("jquery", "1.3.2"); google.setOnLoadCallback(function() { $('#loadButton').click(loadDataFromExernalWebsite); }); function loadDataFromExernalWebsite() { $('#content').load('http://www.tanguay.info/knowsite/data.txt', function() { alert('Load was performed.'); }); } </script> </head> <body> <p>Click the button to load content:</p> <p id="content"></p> <input id="loadButton" type="button" value="load content"/> </body> </html>

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  • memory tuning with rails/unicorn running on ubuntu

    - by user970193
    I am running unicorn on Ubuntu 11, Rails 3.0, and Ruby 1.8.7. It is an 8 core ec2 box, and I am running 15 workers. CPU never seems to get pinned, and I seem to be handling requests pretty nicely. My question concerns memory usage, and what concerns I should have with what I am seeing. (if any) Here is the scenario: Under constant load (about 15 reqs/sec coming in from nginx), over the course of an hour, each server in the 3 server cluster loses about 100MB / hour. This is a linear slope for about 6 hours, then it appears to level out, but still maybe appear to lose about 10MB/hour. If I drop my page caches using the linux command echo 1 /proc/sys/vm/drop_caches, the available free memory shoots back up to what it was when I started the unicorns, and the memory loss pattern begins again over the hours. Before: total used free shared buffers cached Mem: 7130244 5005376 2124868 0 113628 422856 -/+ buffers/cache: 4468892 2661352 Swap: 33554428 0 33554428 After: total used free shared buffers cached Mem: 7130244 4467144 2663100 0 228 11172 -/+ buffers/cache: 4455744 2674500 Swap: 33554428 0 33554428 My Ruby code does use memoizations and I'm assuming Ruby/Rails/Unicorn is keeping its own caches... what I'm wondering is should I be worried about this behaviour? FWIW, my Unicorn config: worker_processes 15 listen "#{CAPISTRANO_ROOT}/shared/pids/unicorn_socket", :backlog = 1024 listen 8080, :tcp_nopush = true timeout 180 pid "#{CAPISTRANO_ROOT}/shared/pids/unicorn.pid" GC.respond_to?(:copy_on_write_friendly=) and GC.copy_on_write_friendly = true before_fork do |server, worker| STDERR.puts "XXXXXXXXXXXXXXXXXXX BEFORE FORK" print_gemfile_location defined?(ActiveRecord::Base) and ActiveRecord::Base.connection.disconnect! defined?(Resque) and Resque.redis.client.disconnect old_pid = "#{CAPISTRANO_ROOT}/shared/pids/unicorn.pid.oldbin" if File.exists?(old_pid) && server.pid != old_pid begin Process.kill("QUIT", File.read(old_pid).to_i) rescue Errno::ENOENT, Errno::ESRCH # already killed end end File.open("#{CAPISTRANO_ROOT}/shared/pids/unicorn.pid.ok", "w"){|f| f.print($$.to_s)} end after_fork do |server, worker| defined?(ActiveRecord::Base) and ActiveRecord::Base.establish_connection defined?(Resque) and Resque.redis.client.connect end Is there a need to experiment enforcing more stringent garbage collection using OobGC (http://unicorn.bogomips.org/Unicorn/OobGC.html)? Or is this just normal behaviour, and when/as the system needs more memory, it will empty the caches by itself, without me manually running that cache command? Basically, is this normal, expected behaviour? tia

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  • What is causing the unusual high load average?

    - by James
    I noticed on Tuesday night of last week, the load average went up sharply and it seemed abnormal since the traffic is small. Usually, the numbers usually average around .40 or lower and my server stuff (mysql, php and apache) are optimized. I noticed that the IOWait is unusually high even though the processes is barely using any CPU. top - 01:44:39 up 1 day, 21:13, 1 user, load average: 1.41, 1.09, 0.86 Tasks: 60 total, 1 running, 59 sleeping, 0 stopped, 0 zombie Cpu0 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu1 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu2 : 0.0%us, 0.3%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu3 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu4 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu5 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu6 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu7 : 0.0%us, 0.0%sy, 0.0%ni, 91.5%id, 8.5%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1048576k total, 331944k used, 716632k free, 0k buffers Swap: 0k total, 0k used, 0k free, 0k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1 root 15 0 2468 1376 1140 S 0 0.1 0:00.92 init 1656 root 15 0 13652 5212 664 S 0 0.5 0:00.00 apache2 9323 root 18 0 13652 5212 664 S 0 0.5 0:00.00 apache2 10079 root 18 0 3972 1248 972 S 0 0.1 0:00.00 su 10080 root 15 0 4612 1956 1448 S 0 0.2 0:00.01 bash 11298 root 15 0 13652 5212 664 S 0 0.5 0:00.00 apache2 11778 chikorit 15 0 2344 1092 884 S 0 0.1 0:00.05 top 15384 root 18 0 17544 13m 1568 S 0 1.3 0:02.28 miniserv.pl 15585 root 15 0 8280 2736 2168 S 0 0.3 0:00.02 sshd 15608 chikorit 15 0 8280 1436 860 S 0 0.1 0:00.02 sshd Here is the VMStat procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 1 0 0 768644 0 0 0 0 14 23 0 10 1 0 99 0 IOStat - Nothing unusal Total DISK READ: 67.13 K/s | Total DISK WRITE: 0.00 B/s TID PRIO USER DISK READ DISK WRITE SWAPIN IO COMMAND 19496 be/4 chikorit 11.85 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 19501 be/4 mysql 3.95 K/s 0.00 B/s 0.00 % 0.00 % mysqld 19568 be/4 chikorit 11.85 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 19569 be/4 chikorit 11.85 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 19570 be/4 chikorit 11.85 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 19571 be/4 chikorit 7.90 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 19573 be/4 chikorit 7.90 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 1 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % init 11778 be/4 chikorit 0.00 B/s 0.00 B/s 0.00 % 0.00 % top 19470 be/4 mysql 0.00 B/s 0.00 B/s 0.00 % 0.00 % mysqld Load Average Chart - http://i.stack.imgur.com/kYsD0.png I want to be sure if this is not a MySQL problem before making sure. Also, this is a Ubuntu 10.04 LTS Server on OpenVZ. Edit: This will probably give a good picture on the IO Wait top - 22:12:22 up 17:41, 1 user, load average: 1.10, 1.09, 0.93 Tasks: 33 total, 1 running, 32 sleeping, 0 stopped, 0 zombie Cpu(s): 0.6%us, 0.2%sy, 0.0%ni, 89.0%id, 10.1%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1048576k total, 260708k used, 787868k free, 0k buffers Swap: 0k total, 0k used, 0k free, 0k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1 root 15 0 2468 1376 1140 S 0 0.1 0:00.88 init 5849 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 8063 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 9732 root 16 0 8280 2728 2168 S 0 0.3 0:00.02 sshd 9746 chikorit 18 0 8412 1444 864 S 0 0.1 0:01.10 sshd 9747 chikorit 18 0 4576 1960 1488 S 0 0.2 0:00.24 bash 13706 chikorit 15 0 2344 1088 884 R 0 0.1 0:00.03 top 15745 chikorit 15 0 12968 5108 1280 S 0 0.5 0:00.00 apache2 15751 chikorit 15 0 72184 25m 18m S 0 2.5 0:00.37 php5-fpm 15790 chikorit 18 0 12472 4640 1192 S 0 0.4 0:00.00 apache2 15797 chikorit 15 0 72888 23m 16m S 0 2.3 0:00.06 php5-fpm 16038 root 15 0 67772 2848 592 D 0 0.3 0:00.00 php5-fpm 16309 syslog 18 0 24084 1316 992 S 0 0.1 0:00.07 rsyslogd 16316 root 15 0 5472 908 500 S 0 0.1 0:00.00 sshd 16326 root 15 0 2304 908 712 S 0 0.1 0:00.02 cron 17464 root 15 0 10252 7560 856 D 0 0.7 0:01.88 psad 17466 root 18 0 1684 276 208 S 0 0.0 0:00.31 psadwatchd 17559 root 18 0 11444 2020 732 S 0 0.2 0:00.47 sendmail-mta 17688 root 15 0 10252 5388 1136 S 0 0.5 0:03.81 python 17752 teamspea 19 0 44648 7308 4676 S 0 0.7 1:09.70 ts3server_linux 18098 root 15 0 12336 6380 3032 S 0 0.6 0:00.47 apache2 18099 chikorit 18 0 10368 2536 464 S 0 0.2 0:00.00 apache2 18120 ntp 15 0 4336 1316 984 S 0 0.1 0:00.87 ntpd 18379 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 18387 mysql 15 0 62796 36m 5864 S 0 3.6 1:43.26 mysqld 19584 root 15 0 12336 4028 668 S 0 0.4 0:00.02 apache2 22498 root 16 0 12336 4028 668 S 0 0.4 0:00.00 apache2 24260 root 15 0 67772 3612 1356 S 0 0.3 0:00.22 php5-fpm 27712 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 27730 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 30343 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 30366 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 This is the free ram as of today. total used free shared buffers cached Mem: 1024 302 721 0 0 0 -/+ buffers/cache: 302 721 Swap: 0 0 0 Update: Looking into the logs, particularly the PHP5-FPM, which is causing the CPU spike. I found that its segment faulting for some apparent reason. [03-Jun-2012 06:11:20] NOTICE: [pool www] child 14132 started [03-Jun-2012 06:11:25] WARNING: [pool www] child 13664 exited on signal 11 (SIGSEGV) after 53.686322 seconds from start [03-Jun-2012 06:11:25] NOTICE: [pool www] child 14328 started [03-Jun-2012 06:11:25] WARNING: [pool www] child 14132 exited on signal 11 (SIGSEGV) after 4.708681 seconds from start [03-Jun-2012 06:11:25] NOTICE: [pool www] child 14329 started [03-Jun-2012 06:11:58] WARNING: [pool www] child 14328 exited on signal 11 (SIGSEGV) after 32.981228 seconds from start [03-Jun-2012 06:11:58] NOTICE: [pool www] child 15745 started [03-Jun-2012 06:12:25] WARNING: [pool www] child 15745 exited on signal 11 (SIGSEGV) after 27.442864 seconds from start [03-Jun-2012 06:12:25] NOTICE: [pool www] child 17446 started [03-Jun-2012 06:12:25] WARNING: [pool www] child 14329 exited on signal 11 (SIGSEGV) after 60.411278 seconds from start [03-Jun-2012 06:12:25] NOTICE: [pool www] child 17447 started [03-Jun-2012 06:13:02] WARNING: [pool www] child 17446 exited on signal 11 (SIGSEGV) after 36.746793 seconds from start [03-Jun-2012 06:13:02] NOTICE: [pool www] child 18133 started [03-Jun-2012 06:13:48] WARNING: [pool www] child 17447 exited on signal 11 (SIGSEGV) after 82.710107 seconds from start I'm thinking that this might be causing the problem. If that is the cause, probably switching it off that to fastcgi/fcgid might resolve it... but still, I want to see if something else might be causing it to do this.

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  • MYSQL Order By Sum of Columns

    - by djs22
    Hi all, Any idea on how to order the results of a MYSQL query by the sum of two columns rather than by a single column? Select * FROM table ORDER BY (col1+col2) desc I know that won't work., but I hope it conveys what I want to do fairly well. Thanks!

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  • select records from table in the order in which i inserted

    - by echo
    consider a tale is as follows, EmployeeId | Name | Phone_Number Now, i insert 10 records... When i query them back, select * from myTable they are not selected in the order i inserted. I can obviously keep an autoincrement index and ORDER BY index. But i dont want to alter the table. How can i do this without altering the table?

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  • Load and Web Performance Testing using Visual Studio Ultimate 2010-Part 3

    - by Tarun Arora
    Welcome back once again, in Part 1 of Load and Web Performance Testing using Visual Studio 2010 I talked about why Performance Testing the application is important, the test tools available in Visual Studio Ultimate 2010 and various test rig topologies, in Part 2 of Load and Web Performance Testing using Visual Studio 2010 I discussed the details of web performance & load tests as well as why it’s important to follow a goal based pattern while performance testing your application. In part 3 I’ll be discussing Test Result Analysis, Test Result Drill through, Test Report Generation, Test Run Comparison, Asp.net Profiler and some closing thoughts. Test Results – I see some creepy worms! In Part 2 we put together a web performance test and a load test, lets run the test to see load test to see how the Web site responds to the load simulation. While the load test is running you will be able to see close to real time analysis in the Load Test Analyser window. You can use the Load Test Analyser to conduct load test analysis in three ways: Monitor a running load test - A condensed set of the performance counter data is maintained in memory. To prevent the results memory requirements from growing unbounded, up to 200 samples for each performance counter are maintained. This includes 100 evenly spaced samples that span the current elapsed time of the run and the most recent 100 samples.         After the load test run is completed - The test controller spools all collected performance counter data to a database while the test is running. Additional data, such as timing details and error details, is loaded into the database when the test completes. The performance data for a completed test is loaded from the database and analysed by the Load Test Analyser. Below you can see a screen shot of the summary view, this provides key results in a format that is compact and easy to read. You can also print the load test summary, this is generated after the test has completed or been stopped.         Analyse the load test results of a previously run load test – We’ll see this in the section where i discuss comparison between two test runs. The performance counters can be plotted on the graphs. You also have the option to highlight a selected part of the test and view details, drill down to the user activity chart where you can hover over to see more details of the test run.   Generate Report => Test Run Comparisons The level of reports you can generate using the Load Test Analyser is astonishing. You have the option to create excel reports and conduct side by side analysis of two test results or to track trend analysis. The tools also allows you to export the graph data either to MS Excel or to a CSV file. You can view the ASP.NET profiler report to conduct further analysis as well. View Data and Diagnostic Attachments opens the Choose Diagnostic Data Adapter Attachment dialog box to select an adapter to analyse the result type. For example, you can select an IntelliTrace adapter, click OK and open the IntelliTrace summary for the test agent that was used in the load test.   Compare results This creates a set of reports that compares the data from two load test results using tables and bar charts. I have taken these screen shots from the MSDN documentation, I would highly recommend exploring the wealth of knowledge available on MSDN. Leaving Thoughts While load testing the application with an excessive load for a longer duration of time, i managed to bring the IIS to its knees by piling up a huge queue of requests waiting to be processed. This clearly means that the IIS had run out of threads as all the threads were busy processing existing request, one easy way of fixing this is by increasing the default number of allocated threads, but this might escalate the problem. The better suggestion is to try and drill down to the actual root cause of the problem. When ever the garbage collection runs it stops processing any pages so all requests that come in during that period are queued up, but realistically the garbage collection completes in fraction of a a second. To understand this better lets look at the .net heap, it is divided into large heap and small heap, anything greater than 85kB in size will be allocated to the Large object heap, the Large object heap is non compacting and remember large objects are expensive to move around, so if you are allocating something in the large object heap, make sure that you really need it! The small object heap on the other hand is divided into generations, so all objects that are supposed to be short-lived are suppose to live in Gen-0 and the long living objects eventually move to Gen-2 as garbage collection goes through.  As you can see in the picture below all < 85 KB size objects are first assigned to Gen-0, when Gen-0 fills up and a new object comes in and finds Gen-0 full, the garbage collection process is started, the process checks for all the dead objects and assigns them as the valid candidate for deletion to free up memory and promotes all the remaining objects in Gen-0 to Gen-1. So in the future when ever you clean up Gen-1 you have to clean up Gen-0 as well. When you fill up Gen – 0 again, all of Gen – 1 dead objects are drenched and rest are moved to Gen-2 and Gen-0 objects are moved to Gen-1 to free up Gen-0, but by this time your Garbage collection process has started to take much more time than it usually takes. Now as I mentioned earlier when garbage collection is being run all page requests that come in during that period are queued up. Does this explain why possibly page requests are getting queued up, apart from this it could also be the case that you are waiting for a long running database process to complete.      Lets explore the heap a bit more… What is really a case of crisis is when the objects are living long enough to make it to Gen-2 and then dying, this is definitely a high cost operation. But sometimes you need objects in memory, for example when you cache data you hold on to the objects because you need to use them right across the user session, which is acceptable. But if you wanted to see what extreme caching can do to your server then write a simple application that chucks in a lot of data in cache, run a load test over it for about 10-15 minutes, forcing a lot of data in memory causing the heap to run out of memory. If you get to such a state where you start running out of memory the IIS as a mode of recovery restarts the worker process. It is great way to free up all your memory in the heap but this would clear the cache. The problem with this is if the customer had 10 items in their shopping basket and that data was stored in the application cache, the user basket will now be empty forcing them either to get frustrated and go to a competitor website or if the customer is really patient, give it another try! How can you address this, well two ways of addressing this; 1. Workaround – A x86 bit processor only allows a maximum of 4GB of RAM, this means the machine effectively has around 3.4 GB of RAM available, the OS needs about 1.5 GB of RAM to run efficiently, the IIS and .net framework also need their share of memory, leaving you a heap of around 800 MB to play with. Because Team builds by default build your application in ‘Compile as any mode’ it means the application is build such that it will run in x86 bit mode if run on a x86 bit processor and run in a x64 bit mode if run on a x64 but processor. The problem with this is not all applications are really x64 bit compatible specially if you are using com objects or external libraries. So, as a quick win if you compiled your application in x86 bit mode by changing the compile as any selection to compile as x86 in the team build, you will be able to run your application on a x64 bit machine in x86 bit mode (WOW – By running Windows on Windows) and what that means is, you could use 8GB+ worth of RAM, if you take away everything else your application will roughly get a heap size of at least 4 GB to play with, which is immense. If you need a heap size of more than 4 GB you have either build a software for NASA or there is something fundamentally wrong in your application. 2. Solution – Now that you have put a workaround in place the IIS will not restart the worker process that regularly, which means you can take a breather and start working to get to the root cause of this memory leak. But this begs a question “How do I Identify possible memory leaks in my application?” Well i won’t say that there is one single tool that can tell you where the memory leak is, but trust me, ‘Performance Profiling’ is a great start point, it definitely gets you started in the right direction, let’s have a look at how. Performance Wizard - Start the Performance Wizard and select Instrumentation, this lets you measure function call counts and timings. Before running the performance session right click the performance session settings and chose properties from the context menu to bring up the Performance session properties page and as shown in the screen shot below, check the check boxes in the group ‘.NET memory profiling collection’ namely ‘Collect .NET object allocation information’ and ‘Also collect the .NET Object lifetime information’.    Now if you fire off the profiling session on your pages you will notice that the results allows you to view ‘Object Lifetime’ which shows you the number of objects that made it to Gen-0, Gen-1, Gen-2, Large heap, etc. Another great feature about the profile is that if your application has > 5% cases where objects die right after making to the Gen-2 storage a threshold alert is generated to alert you. Since you have the option to also view the most expensive methods and by capturing the IntelliTrace data you can drill in to narrow down to the line of code that is the root cause of the problem. Well now that we have seen how crucial memory management is and how easy Visual Studio Ultimate 2010 makes it for us to identify and reproduce the problem with the best of breed tools in the product. Caching One of the main ways to improve performance is Caching. Which basically means you tell the web server that instead of going to the database for each request you keep the data in the webserver and when the user asks for it you serve it from the webserver itself. BUT that can have consequences! Let’s look at some code, trust me caching code is not very intuitive, I define a cache key for almost all searches made through the common search page and cache the results. The approach works fine, first time i get the data from the database and second time data is served from the cache, significant performance improvement, EXCEPT when two users try to do the same operation and run into each other. But it is easy to handle this by adding the lock as you can see in the snippet below. So, as long as a user comes in and finds that the cache is empty, the user locks and starts to get the cache no more concurrency issues. But lets say you are processing 10 requests per second, by the time i have locked the operation to get the results from the database, 9 other users came in and found that the cache key is null so after i have come out and populated the cache they will still go in to get the results again. The application will still be faster because the next set of 10 users and so on would continue to get data from the cache. BUT if we added another null check after locking to build the cache and before actual call to the db then the 9 users who follow me would not make the extra trip to the database at all and that would really increase the performance, but didn’t i say that the code won’t be very intuitive, may be you should leave a comment you don’t want another developer to come in and think what a fresher why is he checking for the cache key null twice !!! The downside of caching is, you are storing the data outside of the database and the data could be wrong because the updates applied to the database would make the data cached at the web server out of sync. So, how do you invalidate the cache? Well if you only had one way of updating the data lets say only one entry point to the data update you can write some logic to say that every time new data is entered set the cache object to null. But this approach will not work as soon as you have several ways of feeding data to the system or your system is scaled out across a farm of web servers. The perfect solution to this is Micro Caching which means you cache the query for a set time duration and invalidate the cache after that set duration. The advantage is every time the user queries for that data with in the time span for which you have cached the results there are no calls made to the database and the data is served right from the server which makes the response immensely quick. Now figuring out the appropriate time span for which you micro cache the query results really depends on the application. Lets say your website gets 10 requests per second, if you retain the cache results for even 1 minute you will have immense performance gains. You would reduce 90% hits to the database for searching. Ever wondered why when you go to e-bookers.com or xpedia.com or yatra.com to book a flight and you click on the book button because the fare seems too exciting and you get an error message telling you that the fare is not valid any more. Yes, exactly => That is a cache failure! These travel sites or price compare engines are not going to hit the database every time you hit the compare button instead the results will be served from the cache, because the query results are micro cached, its a perfect trade-off, by micro caching the results the site gains 100% performance benefits but every once in a while annoys a customer because the fare has expired. But the trade off works in the favour of these sites as they are still able to process up to 30+ page requests per second which means cater to the site traffic by may be losing 1 customer every once in a while to a competitor who is also using a similar caching technique what are the odds that the user will not come back to their site sooner or later? Recap   Resources Below are some Key resource you might like to review. I would highly recommend the documentation, walkthroughs and videos available on MSDN. You can always make use of Fiddler to debug Web Performance Tests. Some community test extensions and plug ins available on Codeplex might also be of interest to you. The Road Ahead Thank you for taking the time out and reading this blog post, you may also want to read Part I and Part II if you haven’t so far. If you enjoyed the post, remember to subscribe to http://feeds.feedburner.com/TarunArora. Questions/Feedback/Suggestions, etc please leave a comment. Next ‘Load Testing in the cloud’, I’ll be working on exploring the possibilities of running Test controller/Agents in the Cloud. See you on the other side! Thank You!   Share this post : CodeProject

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  • php-fpm: very high server load

    - by Derp Derpington
    Since today my webserver (nginx + php-fpm + mysql on a VPS) is very slow. htop says: 1 [|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||100.0%] Tasks: 63 total, 13 running 2 [|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||100.0%] Load average: 11.67 10.95 6.95 3 [|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||100.0%] Uptime: 00:18:40 4 [|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||100.0%] 5 [|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||100.0%] 6 [|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||100.0%] Mem[||||||||||| 137/1280MB] Swp[ 0/0MB] PID USER PRI NI VIRT RES SHR S CPU% MEM% TIME+ Command 6802 www 20 0 76232 12320 5716 R 27.0 0.9 0:06.48 php-fpm: pool www 7048 www 20 0 75200 12136 5700 R 52.0 0.9 0:03.64 php-fpm: pool www 6699 www 20 0 74176 11124 5700 R 27.0 0.8 0:07.36 php-fpm: pool www 7029 www 20 0 73668 10380 5676 R 42.0 0.8 0:03.52 php-fpm: pool www 6995 www 20 0 76228 12456 5644 R 42.0 1.0 0:03.98 php-fpm: pool www 6858 www 20 0 74172 10684 5620 R 35.0 0.8 0:05.52 php-fpm: pool www 6998 www 20 0 75200 12072 5620 R 37.0 0.9 0:03.95 php-fpm: pool www 7098 www 20 0 75200 12052 5616 R 42.0 0.9 0:02.33 php-fpm: pool www 7093 www 20 0 76228 12496 5612 R 37.0 1.0 0:03.02 php-fpm: pool www 7226 www 20 0 74692 11080 5588 R 32.0 0.8 0:00.66 php-fpm: pool www CPU: (cat /proc/cpuinfo | grep model) model : 44 model name : Intel(R) Xeon(R) CPU E5620 @ 2.40GHz model : 44 model name : Intel(R) Xeon(R) CPU E5620 @ 2.40GHz model : 44 model name : Intel(R) Xeon(R) CPU E5620 @ 2.40GHz model : 44 model name : Intel(R) Xeon(R) CPU E5620 @ 2.40GHz model : 44 model name : Intel(R) Xeon(R) CPU E5620 @ 2.40GHz model : 44 model name : Intel(R) Xeon(R) CPU E5620 @ 2.40GHz I think a load of 10 and 100% cpu usage is not normal... How can i fix that?

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