SpotiChart.com
Who?
Idea?


Architecture


Twitter Search
Spotify
Scheduled Stats
Web Site
Feeds & Playlists
What I learned
Unanswered Questions
Stats
Thanks!
@benoitx
SpotiChart.com
A Developer's perspective
Benoit Xhenseval
Tech Architect in the City for... years
Done and sold dot-com
CTO of startup developing a Securities Financing Platform
Looking for a bit of fun!
@benoitx
What does it do?
Find Tweets with a Spotify Item (track, album, artist or playlist)
Supports URI, official and short URL too
Count the Tweets
Create a Global music chart!
Simples...
Entreprise Java Stack
JDK 1.6
Spring 3 and Spring MVC 3
Quartz for scheduling
Maven 3 for build (jetty:run +++)
Hibernate
Transactional & Multi-threaded
Web site does not touch DB
Using Google Analytics and AdSense
Using Twitter4j 2.0.10
Search for 'spotify' every n secs.
Parse URI or short URL
Persist the Tweet and user info
Fetch user details (name/followers)
Deal with limits, broken profile images
Hand-over to another thread for Spotify Fetch (in mem but transactionally)
Reply to users only 1st time:
Avoid spamming
Use Spring msg to support i18n
Twitter determines tweet language...sometime wrong!
Eliminate 'duplicate' tweets postings
From URL contact Spotify and get information:
Track / Album / Artist / Playlist
Store in local DB
Deal with connectivity/timeout issues (transactional)
Every 30 min, refresh stats:
Layer of DAO to collect data (Hibernate)
Result objects stored in Distributed EHCache
Web site will use cache only and be stateless
Stats could be refreshed more frequently
Follow Schedule for Sending Tweets
Quartz (cron); send tweet with stats
Bitlyj to shorten URLs, using j.mp saving a FULL 2 characters... (back to the 70s?)
Using Geo location API for sending tweets... just because we can
Spring MVC 3 RC1
All requests mapped via @Controller and @UrlMapping
Web site only uses EHCache for data
Rendering via JSP and JSON for charts (OpenFlashChart)
Average response time < 10 ms
Heatmap applet from JTreeMap

Atom Feed with Top 10 tracks
Using Rome, result in cache
URI for each entry is key for readers
Spotify Playlists
Top 20 for Day, Week and Month
Both changing and fixed
Quick Development (3 days), yet robust and scalable tech
Twitter:
Twitter API interface quite robust (more than site). Need to deal with:
risk of being flagged a spammer! Solution: be very open about any unsolicited tweet
Slowing down the search requests
Duplicate Tweets appearing in search results (diff IDs but 1 will be invalid)
Invalid users (e.g. spammers removed)
Dealing with limits (150 p/h but app was easily whitelisted and its limit upped! Thank you Twitter)
Broken Profile images fixed thanks to Tweetimag.es They do the hard work!
Twitter4j does not disambiguate User Id vs Screen Name... yet!
Spotify:
A bit of an unknown
Having to deal with incomplete replies / time outs etc
Solution: Transactional and able to re-request missing data
Not using the new Meta-data official API yet... but Playlist are missing in new APIs!
Read fine prints to avoid chosing a domain that violates copyright...
Bitlyj:
Excellent, fast, supports bit.ly and j.mp
Twitter does not return geo-location with a search
Will geo location get a proper format in user profile (at the moment 'anything goes')?
In 2 months:
~1,000 followers @spotichart
~200,000 Tweets with 'spotify'
~50,000 Tweets with a link
~18,000 Tweople
~25,000 Tracks
~20,000 Albums
~12,000 Artists
~5,000 Playlists
AdSense Revenue: enough for a coffee 
(not a venti)

One for the 



10 famous Belgians!



Deployment
7y old PC, 1GB RAM, 320 GB
Ubuntu 9.04
Tomcat 6, single WAR for now
MySQL 5.1