WellTreat.Us a Ruby on Rails based SaaS platform to build your restaurant and business web site on it :)

So i guess my blog title reflects what i’m trying to make point here, YES! This is all about running well treat us as a SaaS platform.

Let me draw a line between those who already got it or those who yet struggling
well, frankly speaking my weekend goes with my newly started start up “http://welltreat.us”

i guess many of those who already have been there might think “Well Treat Us” as a simple platform for reviewing restaurant. This is very true! Indeed, this is a review platform!!

But the fact is far behind the simple review platform “Well Treat Us” is a platform for reviewing ANYTHING that matters in our daily LIFE

Wait a minute! Did you get it ? “Well Treat Us” domain was intentionally picked up so it could be related with “store.WellTreat.Us”, “electricians.WellTreat.Us”, “CarService.WellTreat.Us”, “BookAuthor.WellTreat.Us”, “Movie.WellTreat.Us”, “Newspaper.WellTreat.Us”, “Doctor.WellTreat.Us”, “Government.WellTreat.Us” and it goes on…

so if you are still not getting the idea! I should blame myself for not succeeding to reaching those above words through your tough skull

anyway! In a brief, “Well Treat Us is a platform to read review about our daily mostly used services and products. It helps people and business to grow mutually with feedbacks from each other.”

Ah! let’s back into the topic

So by now you should have understood, “Well Treat Us” is a platform where it can be used for reviewing on anythings, though currently you can only see “http://restaurant.welltreat.us” but at certain point you would be able to see everything that matters your daily living. (we promise)

Keeping this in mind, we have been developing WellTreatUs platform following agile and lean mindset. Since our inception we have been adding each and every features based on our visitors opinion. Perhaps you spoke that over review or over facebook fan page or in a friendly discussion, we are listening and keeping your wishes in our product feature list (product backlog). So we can give more efforts to bring those for you . we suggest you better don’t feel shy to share what cross your mind.

So let’s back to the main topic

“Well Treat Us” as a SaaS (Software As a Service) how that stands up ?

Well, as i’ve already mentioned well treat us is built on the concept of “topic”.
In every data structure there is dependent parent object which we call “topic” so whatever goes through the “Well Treat Us” every contents are put under specific “topic”. This topic based architecture helped us to isolate and identify separate type of contents. (ie. Doctors, books, restaurants, donors, stores etc..)

Just imagine your web site is built on “Well Treat Us” CMS

So as “Well Treat Us” is a platform for hosting several topics dependent review platform, we kept another side around which enables us to provide a complete make over using your own preference to build your own business web site or e-commerce store.

Let me make it more understandable. As you can see today you can browse any restaurant page which looks like the following picture -
http://restaurant.welltreat.us/t/restaurants/captains-world/4?l=en

As you can see every restaurant page comes with a simple predefined attributes, such as title, description, tags, location, images and so on. Which can be varied from topic to topic, for example – doctors review site might need different attributes than what we have with restaurant. Fortunately everything could be configured over topic administration system as we have in well treat us admin panel.

A different make over as your wish!

“Well Treat Us” is not only about having multiple topics based review platform it is also about creating web site for your own business need. Where “Well Treat Us” as SaaS comes into play.
The following image is an illustration how it could help you to build your web site as your own wishes and preferences. Check it out -

Also don’t forget about having your own web site address (ie. Http://laalshop.com) and so much customization that you can do with any CMS these days. (like joomla, sitefinity etc..)

“Well Treat Us” Web Site Content Management System – “We kept Everything Visual!”
Till now we haven’t unveiled the GREAT secret about “Well Treat Us”, you might be wondering what that could be ? Well you know! You know! the secret is all about secret we shouldn’t unveil it well here is the secret -

“We have build “Well Treat Us” for our own usages” it means, we haven’t built it for having another fancy service around, we built it because we meant it we wanted it. We kept it mind that we are gonna use it for our own purposes. Our business ideas and web sites will be built on it.

So you can understand, how much efforts we give only to keep it more useable for our own demand. We have been doing it with passion for us and for our clients.

Let us show you some examples, how does it looks, when you have a web site on well treat us SaaS platform

A web site built on “Well Treat Us SaaS paltform”

This is an example, how your web site's featured images are administrated over the admin panel.

This is another example which demonstrates how easy it is to let you manage your web site menu on the fly.

Ah! what a easy way to create a new content with SEO friendly url

It's your web site, you got freedom and control, so you better add as much video clip as you want -

Also control total number of items to be displayed -

Also you are king of your own content edit it live on the site in edit mode so you can see how might appear on screen

I guess i should have completed my post bit earlier but my passion toke me further. Anyway! Thanks for reading the whole thing

best wishes,

Ruby Twitter OAuth API : 401 Unauthorized error also says Failed to validate oauth signature and token

Ah! what a waste, after trying out for couple of hours i’ve suddenly found out a blessing post from “blaine garrett” . hussss! he really got it fixed through synchronizing system time. my system time was around 30 mins beyond twitter server time.

so far i can assume, this problem was occurring due to twitter oauth service call validation, since the attached timestamp (through OAuth timestamp or some other header which was carrying request time stamp) was giving far beyond time (ie 30 mins beyond in my case). thus twitter was rejecting the request.

anyway, after synchronizing my system date and time, i can see it’s working.

thanks “baline garrett”

Ruby process & ActiveRecord data set executing in multi cores

You know what! in one of our (tekSymmetry LLC) projects, we have so many background calculations,
which usually takes so many hours to get fully completed. ever since we have introduced those processes,
we were having problem with it’s execution time. sometimes it get’s in nerve

as you know a single ruby process can use a single processor’s core at a time.
this is probable one of the reasons why muli processes based deployment
strategy is picked by ruby on rails community.

anyway, these days our servers got more than one core! more precisely,
in our case each of our production server got 8 cores based intel xeon processor.

so you see the question rose if we could run those long running expensive process in multicores
our system could have better chance to get faster!.

well this blog post is intended for showing you the technique how we have done it in ruby on rails.

for better understanding, let me give you some hints so you can get the context -

• we have big database table rows!
• processing a single row doesn’t require anything from the same database table.
• we are using linux (in our case debian lenny)

so here is the way we have done it -

1. we took the max rows count for the main query
2. and divided by the number of cores we have
3. then we forked child process with each subset of the rows
4. and executed the logic and related stuffs!
5. on the parent process we initiated a loop where it was checking the newly forked process status
6. if all the pid files (which are generated by the newly forked children) are removed,
   parent process will flag it as successful execution thus it will end the loop.

so you see, it is damn! simple _) and it is working for us _),
it has improved our execution time 8x faster, because of getting 8 cores in new server.

here is the code in ruby how we did it. (we created a helper “multicore_execution_helper.rb“  and included in model, thus execute_in_multicores became usable)

module MulticoreExecutionHelper

  def execute_in_multicores(
      p_cores, p_total_rows, p_model, p_conditions = {}, &block)

    p_cores == 2 if p_cores.to_i == 0
    total_items_per_core = p_total_rows / p_cores
    logger.info "[BATCH-PROCESS-LOG] Total processes - #{p_cores}, " +
                "total rows - #{p_total_rows} [#{total_items_per_core} / 1 core]"

    # Create job id for each process
    job_ids = p_cores.times.collect{|i| rand.to_s }

    # Fork process for each core and execute the block
    p_cores.times do |offset|
      Process.fork do
        logger.info "[BATCH-PROCESS-LOG] Starting thread - #{offset} " +
                    "assigned # #{job_ids[offset]}"

        # Keep job track through the created process pid file.
        pid_file = File.join(RAILS_ROOT, 'tmp/pids/', "#{job_ids[offset]}.pid")
        File.open(pid_file, 'w') {|f| f.puts Process.pid.to_s}

        # Since fork process is created from the sample of the parent
        # process's memory so we need to reconnect all live connections.
        begin
          ActiveRecord::Base.connection.reconnect!

          # Retrieve data from the specific row through the defined
          # offset and limit
          teams = p_model.find(
              :all, {
                   ffset => (offset * total_items_per_core),
                  :limit => total_items_per_core}.merge(p_conditions))

          block.call(teams)
        rescue => $e
          logger.error "[BATCH-PROCESS-LOG] Exception raised during " +
                       "execution - #{$e.inspect}"
        end

        # Remove pid since we are done here!
        FileUtils.rm(pid_file)
      end
    end

    # monitor whether the process is completed or still in progress
    # don't return this method unless all the forked processes have
    # completed their job
    sleep(2)

    while 1 do
      fully_completed = true
      for job_id in job_ids
        pid_file = File.join(RAILS_ROOT, 'tmp/pids/', "#{job_id}.pid")
        if fully_completed && File.exists?(pid_file)
          fully_completed = false
          break
        end
      end

      break if fully_completed
      sleep(2)
      logger.debug '[BATCH-PROCESS-LOG] again...'
    end
  end

end

here is the usages code -

      execute_in_multicores(p_total_cores, SomeStuff.count, SomeStuff) do |some_stuffs|
        # Do.. whatever you wanna do with the stuff here! these are gonna run on multicores!
      end

see it is really simple!  _) if you like it let me know! how much you like it  _)
here you can find the code on github 

best wishes!

Ruby on Rails demo application presentation is picked by slideshare’s editor

Today morning i was informed by an email that my slide on slideshare is picked by their editor to keep it on their featured slides list.

it was really too great things for me. i congrats those slideshare’s guys!

you can check out slide here -

here is the moment i locked it up on screen shot!

debugging rails internal query execution

while we were working with somewhere in… ads project we came up with some debugging and performance mesuring tool, here in my post i will describe how you can use it for yourself.

query debugging –

query debugging tool logs every executed query from active record and keep them in memory and using assisting template code it display all executed query from the active page.

also it executes query with mysql “explain” keyword. so on the same window you can see mysql query execution plan.
it helped us to track down queries which were not hitting the right index.
this is very simple trick – go through the code below -

module DebugUtil
class QueryDebug
@@QUERIES = {}
def self.add(p_query, p_report)
@@QUERIES[p_query] = p_report
end

def self.queries
q = @@QUERIES
clean
return q
end

def self.clean
@@QUERIES = {}
end
end
end

QueryDebug class keeps all executed query and their explained resultset in to the static array. so later in template QueryDebug::queries is invoked to get all executed query for the current page.

here is how we trap the query execution from active record -

if defined?(QUERY_DEBUG_ENABLED) && QUERY_DEBUG_ENABLED
ActiveRecord::ConnectionAdapters::MysqlAdapter.class_eval do
alias __existing_execute_method execute

def execute(sql, name = nil)
if sql.match(/^SELECT/i)
report = []
@connection.query(“explain #{sql}”).each do |row|
report < < row
end
DebugUtil::QueryDebug.add(sql, report)
end
__existing_execute_method(sql, name)
end
end

Object.class_eval do
def raise_during_query_debug
raise DebugUtil::QueryDebug::queries.inspect
end
end
end

you can see we have used “QUERY_DEBUG_ENABLED” constant to ensure whether this is enabled by intention.
now see how we are rendering on our template.

query debug

1. 	checked
   < %= row.join(“	“) % >

we put this code in common layout. so it renders on every page. thats all

time based cache expiry for rails action cache

rails has excellent support for caching action, page, query and so on.
rails default behavior is more than expected for most of the project. though i was looking for some time based expiry function on “caches_action” functionality. unfortunately there wasn’t anything so here is a simple trick i have used to make it work with different url and time based expiration.

i added “caches_action :recent” on my controller and added the following protected method -

protected
def fragment_cache_key(p_args)
cache_key = “cache_key_#{request.path}#{request.headers["QUERY_STRING"]}”.gsub(/=/, “”)
action_cache_key = get_from_cache(cache_key)
if action_cache_key
return action_cache_key
else
action_cache_key = Digest::MD5::hexdigest(“#{rand}#{Time.now}”)
add_to_cache(cache_key, action_cache_key, {:expiry => 1.hours})
return action_cache_key
end

end

actually i generate key and stored them inside my memcached instance with an hour expiry limit.
so when memcache invalidates my cache my action cache is also get invalidated.

so thus rails default action cache work with time limit

don’t think this is all, i suppose to cleanup the previously created cache file so i won’t get unnecessary store consumption .

nginx on debian box

i had a tough time to configure nginx on my debian production environment.
the recent stable release from nginx is 0.6.x but on debian repository it was 0.4.x, so i had to build it from the source and install it.

since i had an old 0.4.x instance of nginx, installation wasn’t as smooth as i was expecting. here i would try to show how i have resolved those broken issues and made my way to run nginx to reverse proxy my backend mongrel instances.

i took several attemtps to remove the existing 0.4.x instance of nginx but i failed.
i used “aptitude remove nginx” i ended with the following error -

Reading package lists… Done
Building dependency tree
Reading state information… Done
The following packages will be REMOVED:
nginx
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
Need to get 0B of archives.
After unpacking 582kB disk space will be freed.
Do you want to continue [Y/n]?
(Reading database … 78227 files and directories currently installed.)
Removing nginx …
Stopping nginx: nginx.
Stopping nginx: invoke-rc.d: initscript nginx, action “stop” failed.
dpkg: error processing nginx (–remove):
subprocess pre-removal script returned error exit status 1
Starting nginx: nginx.
Errors were encountered while processing:
nginx
E: Sub-process /usr/bin/dpkg returned an error code (1)

though this is not my real error code but it has similarity, i took it from the following url -

http://sudhanshuraheja.com/2007/09/remove-nginx-from-ubuntu-fiesty-fawn.html

this blog author had some suggestion, but that wasn’t working for me, so i tried in different way -
i executed “sudo apt-get build-dep nginx” i found this tips from one of the blog comments
the comment author explained in this way -

“this should install everything required to build the package (compiler, headers/libs, packaging tools). Usually on a fresh install I do this to get everything required to build zope.Then issue “apt-get source nginx” (you need deb-src sources in /etc/apt/sources.list). This will download nginx sources (original tarball, diff, and uncompressed sources with patches applied). Just cd in source dir, make your modifications and use “dpkg-buildpackage -rfakeroot -b” (this requires fakeroot package). In parent directory you should get new deb files ready to install, with start/stops scripts and your patches. Just take care of package update that will surely remove your nginx version.”

if you want service script to initiate nginx on startup follow the link -
http://blog.labratz.net/articles/2006/10/03/rails-deployment-apache-lighttpd-nginx-mongrel-cluster

best wishes,

upcoming project mojar_workflow, workflow engine in ruby

hi,
we just kicking start a new open source ruby based workflow engine project “mojar workflow“.
we named it after our deshi word “mojar” reason is very clear to
spread out this word.

mojar workflow, is integral solution to execute a flow of business
rules. for example -

you have an action where you have the following set of rules -
1. start transaction
2. verify user account
3. verify user balance
4. verify user dues
5. reduce dues from balance
6. complete transaction

after few days you got a new requirement, where you suppose to reduce
user dues by the 10% because of company new discount policy.
so you have to implement the following rules -
1. start transaction
2. verify user account
3. verify user balance
4. verify user dues
5. reduce dues by 10% of discount
5. reduce discounted dues from balance
6. complete transaction

to implement such scenario you have to again code in your stable
release. but using mojar workflow, you can add that new concern from
the abstract flow maintenance layer. where you can define this flow in
yaml file or an xml document.

keep your eyes on -
http://rubyforge.org/projects/mojarworkflow/

best wishes,

rails plugin symlinked broken on 1.2.5, fixed from 2.0

i was trying to build a rails plugin. my project was in different directory so i symlinked the directory under “vendor/plugins/..”. but i couldn’t find it working.

so after passing few times, i could successfully run my plugin under rails 2.0-RC2. so later i compared lookup.rb file from the 1.5 and 2.0-RC2 release.

the defecting code was the following lines – (1.5)

def use_component_sources!
# ….
sources < < PathSource.new(:lib, “#{::RAILS_ROOT}/lib/generators”)
sources << PathSource.new(:vendor, “#{::RAILS_ROOT}/vendor/generators”)
sources << PathSource.new(:plugins, “#{::RAILS_ROOT}/vendor/plugins/**/generators”)
# ….
end

the fixed version – (2.0-RC2)

def use_component_sources!
# …

sources < < PathSource.new(:lib, “#{::RAILS_ROOT}/lib/generators”)
sources << PathSource.new(:vendor, “#{::RAILS_ROOT}/vendor/generators”)
sources << PathSource.new(:plugins, “#{::RAILS_ROOT}/vendor/plugins/*/**/generators”)
sources << PathSource.new(:plugins, “#{::RAILS_ROOT}/vendor/plugins/*/**/rails_generators”)
end
# …
end

i also checked out rails bug tracker i found a bug was pointed to this issue and apparently which was fixed on the following change set.
http://dev.rubyonrails.org/changeset/6101

simple fragment cache implementation on ruby on rails

i was getting serious performance problem with one of my projects. so i came up with a simple fragment cache implementation on ruby on rails.

after implementing this stuff, i replaced “render(:partial => …)” with the following method -

render_from_cache_or_render(:cache_key =>”cache key”, :cache_expire_after => ConstantHelper::TAG_CLOUD_EXPIRED_IN, # minutes :partial => “….”)

let’s have a look on my implementation -

def render_from_cache_or_render(p_args)

return render(p_args) if true == p_args[:cache_off]

# check from cache
cache_key = p_args[:cache_key]
cached_content = CacheService.get_cache(cache_key)

if not cached_content.nil? and not cached_content.empty?
return cached_content
else
content = render(p_args)
# cache expire time if defined
cache_expire_time_in_minutes = p_args[:cache_expire_after] || 60
CacheService.add_cache(cache_key, cache_expire_time_in_minutes, content)
return content
end
end

actually, my implemented “CacheService” class is simply storing all cache in a hash map.
when some cache was requested for peek, cache expiry was checked before returning the cached value.

for CacheService implementation look at the bottom of my post.

anyway, after implementing and utilizing this stuff, i gained 70+ requests capability per second. fyi, before applying cache it was around 10 per second.

module Cache
class Item
attr_accessor :key, :expire_time, :content, :created_on

def initialize(p_key, p_expire_time, p_content)
@key = p_key
@expire_time = p_expire_time * 60 # in minutes
@content = p_content
@created_on = Time.now
end
end
end

class CacheService
@@CACHES = {}
@@CACHE_EXPIRE_TIMES = {}

def self.add_cache(p_key, p_expire_time, p_content)
cache_item = Cache::Item.new(p_key, p_expire_time, p_content)
@@CACHES[p_key.to_sym] = cache_item
end

def self.get_cache(p_key)
# load content from cache
cached_content = @@CACHES[p_key.to_sym]
return nil if cached_content.nil?

# verify cache validity
return cached_content.content if not expired?(cached_content)
return nil
end

private
def self.expired?(p_cache)
# find time difference
time_difference = Time.now – p_cache.created_on
return true if time_difference > p_cache.expire_time
end
end

best wishes,