The Art of Social Media Analysis with Twitter & Python

The Art of Social Media Analysis with Twitter & Python krishna sankar @ksankar http://www.oscon.com/oscon2012/public/schedule/detail/23130

Intro API, Objects,… o  House Rules (1 of 2) Twitter Network We will analyze @clouderati, o  Doesn’t assume any knowledge Analysis 2072 followers, exploding to of Twitter API Pipeline ~980,000 distinct users down one level o  Goal: Everybody in the same page & get a working knowledge of Twitter API NLP, NLTK, o  To bootstrap your exploration @mention Cliques, social Sentiment network graph into Social Network Analysis & Analysis Twitter Rewteeet analytics, Growth, #tag Network Information o  Simple programs, to illustrate contagion weakties usage & data manipulation

Intro API, Objects,… Twittero  House Rules (2 of 2) Network We will analyze @clouderati, Analysis 2072 followers, exploding to o  Am using the requests library Pipeline ~980,000 distinct users down o  There are good Twitter frameworks one level for python, but wanted to build from the basics. Once one understands the fundamentals, frameworks can help NLP, NLTK, @mention Cliques, social Sentiment o  Many areas to explore – not enough Analysis network graph time. So decided to focus on social graph, cliques & networkx Rewteeet analytics, Growth, #tag Network Information contagion weakties

About Me •  Lead Engineer/Data Scientist/AWS Ops Guy at Genophen.com o  Co-‐chair – 2012 IEEE Precision Time Synchronization •  http://www.ispcs.org/2012/index.html o  Blog : http://doubleclix.wordpress.com/ o  Quora : http://www.quora.com/Krishna-‐Sankar •  Prior Gigs o  Lead Architect (Egnyte) o  Distinguished Engineer (CSCO) o  Employee #64439 (CSCO) to #39(Egnyte) & now #9 ! •  Current Focus: o  Design, build & ops of BioInformatics/Consumer Infrastructure on AWS, MongoDB, Solr, Drupal,GitHub,… o  Big Data (more of variety, variability, context & graphs, than volume or velocity – so far !) o  Overlay based semantic search & ranking •  Other related Presentations o  http://goo.gl/P1rhc Big Data Engineering Top 10 Pragmatics (Summary) o  http://goo.gl/0SQDV The Art of Big Data (Detailed) o  http://goo.gl/EaUKH The Hitchhiker’s Guide to Kaggle OSCON 2011 Tutorial

Twitter Tips – A Baker’s Dozen 1.  Twitter APIs are (more or less) congruent & symmetric 2.  Twitter is usually right & simple -‐ recheck when you get unexpected results before blaming Twitter o  I was getting numbers when I was expecting screen_names in user objects. o  Was ready to send blasting e-‐mails to Twitter team. Decided to check one more time and found that my parameter key was wrong-‐screen_name instead of user_id o  Always test with one or two records before a long run ! - learned the hard way3.  Twitter APIs are very powerful – consistent use can bear huge data o  In a week, you can pull in 4-‐5 million users & some tweets ! o  Night runs are far more faster & error-free4.  Use a NOSQL data store as a command buﬀer & data buﬀer o  Would make it easy to work with Twitter at scale o  I use MongoDB The o  Keep the schema simple & no fancy transformation End •  And as far as possible same as the ( json) response Beg As Th inni o  Use NOSQL CLI for trimming records et al ng e

Twitter Tips – A Baker’s Dozen 5.  Always use a big data pipeline o  Collect - Store - Transform & Analyze - Model & Reason - Predict, Recommend & Visualize o  That way you can orthogonally extend, with functional components like command buffers, validation et al 6.  Use functional approach for a scalable pipeline o  Compose your data big pipeline with well defined granular functions, each doing only one thing o  Don’t overload the functional components (i.e. no collect, unroll & store as a single component) o  Have well defined functional components with appropriate caching, buffering, checkpoints & restart techniques •  This did create some trouble for me, as we will see later7.  Crawl-‐Store-‐Validate-‐Recrawl-‐Refresh cycle o  The equivalent of the traditional ETL o  Validation stage & validation routines are important •  Cannot expect perfect runs •  Cannot manually look at data either, when data is at scale 8.  Have control numbers to validate runs & monitor them o  I still remember control numbers which start with the number of punch cards in the input deck &d then follow that number through the various runs ! o  There will be a separate printout of the control numbers that will be kept in the operations files

Twitter Tips – A Baker’s Dozen 9.  Program defensively o  more so for a REST-based-Big Data-Analytics systems o  Expect failures at the transport layer & accommodate for them 10.  Have Erlang-‐style supervisors in your pipeline o  Fail fast & move on o  Don’t linger and try to ﬁx errors that cannot be controlled at that layer o  A higher layer process will circle back and do incremental runs to correct missing spiders and crawls o  Be aware of visibility & lack of context. Validate at the lowest layer that has enough context to take corrective actions o  I have an example in part 211.  Data will never be perfect o  Know your data & accommodate for it’s idiosyncrasies •  for example: 0 followers, protected users, 0 friends,…

Twitter Tips – A Baker’s Dozen 12.  Check Point frequently (preferably after ever API call) & have a re-‐startable command buﬀer cache o  See a MongoDB example in Part 213.  Don’t bombard the URL o  Wait a few seconds before successful calls. This will end up with a scalable system, eventually o  I found 10 seconds to be the sweet spot. 5 seconds gave retry error. Was able to work with 5 seconds with wait & retry. Then, the rate limit started kicking in ! 14.  Always measure the elapsed time of your API runs & processing o  Kind of early warning when something is wrong 15.  Develop incrementally; don’t fail to check “cut & paste” errors

Twitter Tips – A Baker’s Dozen 16.  The Twitter big data pipeline has lots of opportunities for parallelism o  Leverage data parallelism frameworks like MapReduce o  But ﬁrst : §  Prototype as a linear system, §  Optimize and tweak the functional modules & cache strategies, §  Note down stages and tasks that can be parallelized and §  Then parallelize them o  For the example project, we will see later, I did not leverage any parallel frameworks, but the opportunities were clearly evident. I will point them out, as we progress through the tutorial17.  Pay attention to handoﬀs between stages o  They might require transformation – for example collect & store might store a user list as multiple arrays, while the model requires each user to be a document for aggregation o  But resist the urge to overload collect with transform o  i.e let the collect stage store in arrays, but then have an unroll/flatten stage to transform the array to separate documents o  Add transformation as a granular function – of course, with appropriate buffering, caching, checkpoints & restart techniques 18.  Have a good log management system to capture and wade through logs

Twitter Tips – A Baker’s Dozen 19.  Understand the underlying network characteristics for the inference you want to make o  Twitter Network != Facebook Network , Twitter Graph != LinkedIn Graph o  Twitter Network is more of an Interest Network o  So, many of the traditional network mechanisms & mechanics, like network diameter & degrees of separation, might not make sense o  But, others like Cliques and Bipartite Graphs do

Twitter Gripes 1.  Need more rich APIs for #tags o  Somewhat similar to users viz. followers, friends et al o  Might make sense to make #tags a top level object with it’s own semantics 2.  HTTP Error Return is not uniform o  Returns 400 bad Request instead of 420 o  Granted, there is enough information to figure this out3.  Need an easier way to get screen_name from user_id 4.  “following” vs. “friends_count” i.e. “following” is a dummy variable. o  There are a few like this, most probably for backward compatibility5.  Parameter Validation is not uniform o  Gives “404 Not found” instead of “406 Not Acceptable” or “413 Too Long” or “416 Range Unacceptable” 6.  Overall more validation would help o  Granted, it is more of growing pains. Once one comes across a few inconsistencies, the rest is easy to figure out

A Fork & deep ,NLTK •   NLP weets into T ment 4 o  Sen ysis Anal • Not enough time for both • I chose the Social Graph route

A minute about Twitter as platform & it’s evolution blog/ er. com/ tter-‐ twitt wi ps:/ /dev. nsistent-‐t htt ring-‐co e deliv ence “The micro-blogging service must find the ri expe right balance of running a profitable business and maintaining a robust “.. we want to make sure that the Twitter experience is developers community.” – Chenda, CBS straightforward and easy to understand -- whether you’re on news! Twitter.com or elsewhere on the web”-Michael!My Wish & Hope •  I spend a lot of time with Twitter & derive value; the platform is rich & the APIs intuitive •  I did like the fact that tweets are part of LinkedIn. I still used Twitter more than LinkedIn o  I don’t think showing Tweets in LinkedIn took anything away from the Twitter experience o  LinkedIn experience & Twitter experience are diﬀerent & distinct. Showing tweets in LinkedIn didn’t change that •  I sincerely hope that the platform grows with a rich developer eco system •  Orthogonally extensible platform is essential •  Of course, along with a congruent user experience – “ … core Twitter consumption experience through consistent tools”

•  For Hands on Today Setup o  Python 2.7.3 o  easy_install –v requests •  http://docs.python-‐requests.org/en/latest/user/quickstart/#make-‐a-‐ request o  easy_install –v requests-‐oauth o  Hands on programs at https://github.com/xsankar/oscon2012-‐handson •  For advanced data science with social graphs o  easy_install –v networkx o  easy_install –v numpy o  easy_install –v nltk •  Not for this tutorial, but good for sentiment analysis et al o  Mongodb •  I used MongoDB in AWS m2.xlarge, RAID 10 X 8 X 15 GB EBS o  graphviz -‐ http://www.graphviz.org/; easy_install pygraphviz o  easy_install pydot

Thanks To these Giants …

Problem Domain For this tutorial •  Data Science (trends, analytics et al) on Social Networks as observed by Twitter primitives o  Not for Twitter based apps for real time tweets o  Not web sites with real time tweets •  By looking at the domain in aggregate to derive inferences & actionable recommendations •  Which also means, you need to be deliberate & systemic ( i.e. not look at a ﬂuctuation as a trend but dig deeper before pronouncing a trend)

Agenda I.  Mechanics : Twitter API (1:30 PM -‐ 3:00 PM) o  Essential Fundamentals (Rate Limit, HTTP Codes et al) o  Objects o  API o  Hands-‐on (2:45 PM -‐ 3:00 PM) II.  Break (3:00 PM -‐ 3:30 PM) III.  Twitter Social Graph Analysis (3:30 PM -‐ 5:00 PM) o  Underlying Concepts o  Social Graph Analysis of @clouderati §  Stages, Strategies & Tasks §  Code Walk thru

Open This First

Twi5er API : Read These First •  Using Twitter Brand o  New logo & associated guidelines : https://twitter.com/about/logos o  Twitter Rules : https://support.twitter.com/groups/33-‐report-‐a-‐violation/topics/121-‐guidelines-‐ best-‐practices/articles/18311-‐the-‐twitter-‐rules o  Developer Rules of the road https://dev.twitter.com/terms/api-‐terms •  Read These Links First 1.  https://dev.twitter.com/docs/things-‐every-‐developer-‐should-‐know 2.  https://dev.twitter.com/docs/faq 3.  Field Guide to Objects https://dev.twitter.com/docs/platform-‐objects 4.  Security https://dev.twitter.com/docs/security-‐best-‐practices 5.  Media Best Practices : https://dev.twitter.com/media 6.  Consolidates Page : https://dev.twitter.com/docs 7.  Streaming APIs https://dev.twitter.com/docs/streaming-‐apis 8.  How to Appeal (Not that you all would need it !) https://support.twitter.com/ articles/72585 •  Only One version of Twitter APIs

API Status Page •  https://dev.twitter.com/status •  https://dev.twitter.com/issues •  https://dev.twitter.com/discussions

h5ps://dev.twi5er.com/status http://www.buzzfeed.com/tommywilhelm/google-‐users-‐being-‐total-‐dicks-‐about-‐the-‐twitter

Open This First •  Install pre-‐req as per the setup slide •  Run o  oscon2012_open_this_ﬁrst.py o  To test connectivity – “canary query” •  Run o  oscon2012_rate_limit_status.py o  Use http://www.epochconverter.com to check reset_time •  Formats xml, json, atom & rss

Twitter API Near-realtime, High Volume Follow users,Core Data, REST Streaming topics, dataCore Twitter mining Objects Public Streams Seach & User Streams Trend Twitter Twitter Site Streams REST Search Firehose Build Proﬁle Keywords Create/Post Tweets Speciﬁc User Reply Trends Favorite, Re-‐tweet Rate Limit : Rate Limit : 150/350 Complexity & Frequency

Rate Limit

Rate Limits •  By API type & Authentication Mode API No authC authC Error REST 150/hr 350/hr 400 Search Complexity & -‐N/A-‐ 420 Frequency Streaming Upto 1% Fire hose none none

Rate Limit Header •  { •  "status": "200 OK", •  "vary": "Accept-‐Encoding", •  "x-‐frame-‐options": "SAMEORIGIN", •  "x-‐mid": "8e775a9323c45f2a541eeb4d2d1eb9b468w81c6", •  "x-‐ratelimit-‐class": "api", •  "x-‐ratelimit-‐limit": "150", •  "x-‐ratelimit-‐remaining": "149", •  "x-‐ratelimit-‐reset": "1340467358", •  "x-‐runtime": "0.04144", •  "x-‐transaction": "2b49ac31cf8709af", •  "x-‐transaction-‐mask": "a6183ﬀa5f8ca943ﬀ1b53b5644ef114df9d6bba" •  }

Rate Limit-‐‑ed Header •  { •  "cache-‐control": "no-‐cache, max-‐age=300", •  "content-‐encoding": "gzip", •  "content-‐length": "150", •  "content-‐type": "application/json; charset=utf-‐8", •  "date": "Wed, 04 Jul 2012 00:48:25 GMT", •  "expires": "Wed, 04 Jul 2012 00:53:25 GMT", •  "server": "tfe", •  ”… •  "status": "400 Bad Request", •  "vary": "Accept-‐Encoding", •  "x-‐ratelimit-‐class": "api", •  "x-‐ratelimit-‐limit": "150", •  "x-‐ratelimit-‐remaining": "0", •  "x-‐ratelimit-‐reset": "1341363230", •  "x-‐runtime": "0.01126" •  }

Rate Limit Example •  Run o  oscon2012_rate_limit_02.py •  It iterates through a list to get followers •  List is 2072 long

•  { •  … •  "date": "Wed, 04 Jul 2012 00:54:16 GMT", •  "status": "200 OK", •  "vary": "Accept-‐Encoding", •  "x-‐frame-‐options": "SAMEORIGIN", •  "x-‐mid": "f31c7278ef8b6e28571166d359132f152289c3b8", •  "x-‐ratelimit-‐class": "api", •  "x-‐ratelimit-‐limit": "150", Last time, it gave me 5 min. Now the reset timer is 1 •  "x-‐ratelimit-‐remaining": "147", hour •  "x-‐ratelimit-‐reset": "1341366831", 150 calls, not authenticated •  "x-‐runtime": "0.02768", •  "x-‐transaction": "f1bafd60112dddeb", •  "x-‐transaction-‐mask": "a6183ﬀa5f8ca943ﬀ1b53b5644ef11417281dbc" •  }

•  { •  "cache-‐control": "no-‐cache, max-‐age=300", •  "content-‐encoding": "gzip", •  "content-‐type": "application/json; charset=utf-‐8", •  "date": "Wed, 04 Jul 2012 00:55:04 GMT", And Rate Limit kicked-‐‑in •  … •  "status": "400 Bad Request", •  "transfer-‐encoding": "chunked", •  "vary": "Accept-‐Encoding", •  "x-‐ratelimit-‐class": "api", •  "x-‐ratelimit-‐limit": "150", •  "x-‐ratelimit-‐remaining": "0", •  "x-‐ratelimit-‐reset": "1341366831", •  "x-‐runtime": "0.01342" •  }

API with OAuth •  { •  … •  "date": "Wed, 04 Jul 2012 01:32:01 GMT", •  "etag": ""dd419c02ed00fc6b2a825cc27wbe040"", •  "expires": "Tue, 31 Mar 1981 05:00:00 GMT", •  "last-‐modified": "Wed, 04 Jul 2012 01:32:01 GMT", •  "pragma": "no-‐cache", •  "server": "tfe", •  … •  "status": "200 OK", •  "vary": "Accept-‐Encoding", •  "x-‐access-‐level": "read", •  "x-‐frame-‐options": "SAMEORIGIN", •  "x-‐mid": "5bbb87c04fa43c43bc9d7482bc62633a1ece381c", •  "x-‐ratelimit-‐class": "api_identified", •  "x-‐ratelimit-‐limit": "350", •  "x-‐ratelimit-‐remaining": "349", •  "x-‐ratelimit-‐reset": "1341369121", •  "x-‐runtime": "0.05539", OAuth • •  "x-‐transaction": "9f8508fe4c73a407", "x-‐transaction-‐mask": "a6183ffa5f8ca943ff1b53b5644ef11417281dbc" “api-‐identified” •  } 1 hr reset 350 calls

•  { •  … •  "date": "Thu, 05 Jul 2012 14:56:05 GMT", •  … •  "x-‐ratelimit-‐class": "api_identiﬁed", •  "x-‐ratelimit-‐limit": "350", •  "x-‐ratelimit-‐remaining": "133", •  "x-‐ratelimit-‐reset": "1341500165", •  … Rate Limit resets during •  } consecutive calls •  ******** 2416 •  { +1 •  … hour •  "date": "Thu, 05 Jul 2012 14:56:18 GMT", •  … •  "status": "200 OK", •  …. •  "x-‐ratelimit-‐class": "api_identiﬁed", •  "x-‐ratelimit-‐limit": "350", •  "x-‐ratelimit-‐remaining": "349", •  "x-‐ratelimit-‐reset": "1341503776", •  ******** 2417

Unexplained Errors •  Traceback (most recent call last): •  File "oscon2012_get_user_info_01.py", line 39, in <module> •  r = client.get(url, params=payload) •  File "build/bdist.macosx-‐10.6-‐intel/egg/requests/sessions.py", line 244, in get •  File "build/bdist.macosx-‐10.6-‐intel/egg/requests/sessions.py", line 230, in request •  File "build/bdist.macosx-‐10.6-‐intel/egg/requests/models.py", line 609, in send •  requests.exceptions.ConnectionError: HTTPSConnectionPool(host=api.twitter.com, port=443): Max retries exceeded with url: /1/users/lookup.json? user_id=237552390%2C101237516%2C208192270%2C340183853%2C221203257%2C15254297%2C44 614426%2C617136931%2C415810340%2C76071717%2C17351462%2C574253%2C35048243%2C38854 7381%2C254329657%2C65585979%2C253580293%2C392741693%2C126403390%2C300467007%2C8 962882%2C21545799%2C15254346%2C141083469%2C340312913%2C44614485%2C600359770%2C While trying to get details of 1,000,000 users, I get this error – 17351519%2C38323042%2C21545828%2C86557546%2C90751854%2C128500592%2C115917681%2C usually 10-‐6 AM PST 42517364%2C34128760%2C15254397%2C453559166%2C92849025%2C600359811%2C17351556%2C 8962952%2C296038349%2C325503810%2C122209166%2C123827693%2C59294611%2C19448725% 2C21545881%2C17351581%2C130468677%2C80266144%2C15254434%2C84680859%2C65586084% Got around by “Trap & wait 5 seconds” 2C19448741%2C15254438%2C214483879%2C48808878%2C88654768%2C15474846%2C48808887% 2C334021563%2C60214090%2C134792126%2C15254464%2C558416833%2C138986435%2C2648155 56%2C63488965%2C17222476%2C537445328%2C97854214%2C255598755%2C65586132%2C362260 Night Runs are relatively error free 09%2C187220954%2C257346383%2C15254493%2C554222558%2C302564320%2C59165520%2C446 14626%2C76071907%2C80266213%2C325503825%2C403227628%2C20368210%2C17351666%2C886 54836%2C340313077%2C151569400%2C302564345%2C118014971%2C11060222%2C233229141%2C 13727232%2C199803906%2C220435108%2C268531201

•  { • •  … "date": "Fri, 06 Jul 2012 03:41:09 GMT", A Day in the life of•  "expires": "Fri, 06 Jul 2012 03:46:09 GMT", Twitter Rate Limit•  "server": "tfe", •  "set-‐cookie": "dnt=; domain=.twitter.com; path=/; expires=Thu, 01-‐Jan-‐1970 00:00:00 GMT", •  "status": "400 Bad Request", •  "vary": "Accept-‐Encoding", •  "x-‐ratelimit-‐class": "api_identiﬁed", •  "x-‐ratelimit-‐limit": "350", •  "x-‐ratelimit-‐remaining": "0", Missed by 4 min! •  "x-‐ratelimit-‐reset": "1341546334", •  "x-‐runtime": "0.01918" •  } •  Error, sleeping •  { •  … •  "date": "Fri, 06 Jul 2012 03:46:12 GMT", •  … •  "status": "200 OK", •  … •  "x-‐ratelimit-‐class": "api_identiﬁed", •  "x-‐ratelimit-‐limit": "350", •  "x-‐ratelimit-‐remaining": "349", OK after 5 min sleep •  …

Strategies I have no exotic strategies, so far ! 1.  Obvious : Track elapsed time & sleep when rate limit kicks in 2.  Combine authenticated & non-‐authenticated calls 3.  Use multiple API types 4.  Cache 5.  Store & get only what is needed 6.  Checkpoint & buﬀer request commands 7.  Distributed data parallelism – for example AWS instances http://www.epochconverter.com/ <-‐ useful to debug the timer Pl share your tips and tricks for conserving the Rate Limit

Authentication

Authentication •  Three modes o  Anonymous o  HTTP Basic Auth o  OAuth •  As of Aug 31, 2010, only Anonymous or OAuth are supported •  OAuth enables the user to authorize an application without sharing credentials •  Also has the ability to revoke •  Twitter supports OAuth 1.0a •  OAuth 2.0 is the new standard, much simpler o  No timeframe for Twitter support, yet

OAuth Pragmatics •  Helpful Links o  https://dev.twitter.com/docs/auth/oauth o  https://dev.twitter.com/docs/auth/moving-‐from-‐basic-‐auth-‐to-‐oauth o  https://dev.twitter.com/docs/auth/oauth/single-‐user-‐with-‐examples o  http://blog.andydenmark.com/2009/03/how-‐to-‐build-‐oauth-‐consumer.html •  Discussion on OAuth internal mechanisms is better left for another day •  For headless applications to get OAuth token, go to https:// dev.twitter.com/apps •  Create an application & get four credential pieces o  Consumer Key, Consumer Secret, Access Token & Access Token Secret •  All the frameworks have support for OAuth. So plug –in these values & use the framework’s calls •  I used request-‐oauth library like so:

request-‐‑oauth def get_oauth_client(): Get client using the consumer_key = "5dbf348aa966c5f7f07e8ce2ba5e7a3badc234bc" token, key & secret from consumer_secret = "fceb3aedb960374e74f559caeabab3562efe97b4" dev.twitter.com/apps access_token = "df919acd38722bc0bd553651c80674fab2b465086782Ls" access_token_secret = "1370adbe858f9d726a43211afea2b2d9928ed878" header_auth = True oauth_hook = OAuthHook(access_token, access_token_secret, consumer_key, consumer_secret, header_auth) client = requests.session(hooks={pre_request: oauth_hook}) return client Use the client instead def get_followers(user_id): of requests url = https://api.twitter.com/1/followers/ids.json’ payload={"user_id":user_id} # if cursor is needed {"cursor":-‐1,"user_id":scr_name} r = requests.get(url, params=payload) def get_followers_with_oauth(user_id,client): url = https://api.twitter.com/1/followers/ids.json payload={"user_id":user_id} # if cursor is needed {"cursor":-‐1,"user_id":scr_name} r = client.get(url, params=payload) Ref: h5p://pypi.python.org/pypi/requests-‐‑oauth

OAuth Authorize screen •  The user authenticates with Twitter & grants access to Forbes Social •  Forbes social doesn’t have the users credentials, but uses OAuth to access the user’s account

HTTP Status Codes

HTTP status Codes •  0 Never made it to Twitter Servers -‐ •  404 Not Found Library error •  406 Not Acceptable •  200 OK •  413 Too Long •  304 Not Modiﬁed •  416 Range Unacceptable •  400 Bad Request •  420 Enhance Your Calm o  Check error message for explanation o  Rate Limited o  REST Rate Limit ! •  500 Internal Server Error •  401 UnAuthorized •  502 Bad Gateway o  Beware – you could get this for other o  Down for maintenance reasons as well. •  503 Service Unavailable •  403 Forbidden o  Overloaded “Fail whale” o  Hit Update Limit (> max Tweets/day, •  504 Gateway Timeout following too many people) o  Overloaded h5ps://dev.twi5er.com/docs/error-‐‑codes-‐‑responses

HTTP Status Code -‐‑ Example •  { •  "cache-‐control": "no-‐cache, max-‐age=300", •  "content-‐encoding": "gzip", •  "content-‐length": "91", •  "content-‐type": "application/json; charset=utf-‐8", •  "date": "Sat, 23 Jun 2012 00:06:56 GMT", •  "expires": "Sat, 23 Jun 2012 00:11:56 GMT", •  "server": "tfe", •  … •  "status": "401 Unauthorized", •  "vary": "Accept-‐Encoding", •  "www-‐authenticate": "OAuth realm="https://api.twitter.com"", • •  "x-‐ratelimit-‐class": "api", "x-‐ratelimit-‐limit": "0", Detailed error •  "x-‐ratelimit-‐remaining": "0", message in JSON ! •  "x-‐ratelimit-‐reset": "1340413616", •  "x-‐runtime": "0.01997" I like this •  } •  { •  "errors": [ •  { •  "code": 53, •  "message": "Basic authentication is not supported" •  } •  ] •  }

HTTP Status Code – Confusing Example •  { •  GET https://api.twitter.com/1/users/lookup.json?•  … screen_nme=twitterapi,twitter&include_entities=•  "pragma": "no-‐cache", true •  "server": "tfe", •  … •  Spelling Mistake •  "status": "404 Not Found", o  Should be screen_name •  … •  But confusing error ! •  } •  { •  Should be 406 Not Acceptable or 413 Too Long , •  "errors": [ showing parameter error •  { •  "code": 34, •  "message": "Sorry, that page does not exist" •  } •  ] •  }

HTTP Status Code -‐‑ Example •  { •  "cache-‐control": "no-‐cache, no-‐store, must-‐revalidate, pre-‐check=0, post-‐check=0", •  "content-‐encoding": "gzip", •  "content-‐length": "112", •  "content-‐type": "application/json;charset=utf-‐8", Sometimes, the errors are •  "date": "Sat, 23 Jun 2012 01:23:47 GMT", not correct. I got this error •  "expires": "Tue, 31 Mar 1981 05:00:00 GMT", •  … for user_timeline.json w/ •  "status": "401 Unauthorized", user_id=20,15,12 •  "www-‐authenticate": "OAuth realm="https://api.twitter.com"", Clearly a parameter error •  "x-‐frame-‐options": "SAMEORIGIN", •  "x-‐ratelimit-‐class": "api", (i.e. more parameters) •  "x-‐ratelimit-‐limit": "150", •  "x-‐ratelimit-‐remaining": "147", •  "x-‐ratelimit-‐reset": "1340417742", •  "x-‐transaction": "d545a806f9c72b98" •  } •  { •  "error": "Not authorized", •  "request": "/1/statuses/user_timeline.json?user_id=12%2C15%2C20" •  }

Objects

Followers Twitter Platform Friends Are Followed By Objects Follow Users Status Update @ user_mentions Entities embed urls Temporally Tweets embe d Ordered media TimeLine # Places hashtags h5ps://dev.twi5er.com/docs/platform-‐‑objects

Tweets •  A.k.a Status Updates •  Interesting ﬁelds o  Coordinates <-‐ geo location o  created_at o  entities (will see later) o  Id, id_str o  possibly sensitive o  user (will see later) •  perspectival attributes embedded within a child object of an unlike parent – hard to maintain at scale •  https://dev.twitter.com/docs/faq#6981 o  withheld_in_countries •  https://dev.twitter.com/blog/new-‐withheld-‐content-‐ﬁelds-‐api-‐responses h5ps://dev.twi5er.com/docs/platform-‐‑objects/tweets

A word about id, id_str •  June 1, 2010 o  Snowflake the id generator service o  “The full ID is composed of a timestamp, a worker number, and a sequence number” o  Had problems with JavaScript to handle numbers > 53 bits o  “id”:819797 o  “id_str”:”819797” h5p://engineering.twi5er.com/2010/06/announcing-‐‑snowflake.html h5ps://groups.google.com/forum/?fromgroups#!topic/twi5er-‐‑development-‐‑talk/ahbvo3VTIYI h5ps://dev.twi5er.com/docs/twi5er-‐‑ids-‐‑json-‐‑and-‐‑snowflake

Tweets -‐‑ example •  Let us run oscon2012-‐tweets.py •  Example of tweet o  coordinates o  id o  id_str

Users •  followers_count •  geo_enabled •  Id, Id_str •  name, screen_name •  Protected •  status, statuses_count •  withheld_in_countries h5ps://dev.twi5er.com/docs/platform-‐‑objects/users

Users – Let us run some examples •  Run o  oscon_2012_users.py •  Lookup users by screen_name o  oscon12_ﬁrst_20_ids.py •  Lookup users by user_id •  Inspect the results o  id, name, status, status_count, protected, followers (for top 10 followers), withheld users •  Can use information for customizing the user’s screen in your web app

Entities •  Metadata & Contextual Information •  You can parse them, but Entities parse them out as structured data •  REST API/Search API – include_entities=1 •  Streaming API – included by default •  hashtags, media, urls, user_mentions h5ps://dev.twi5er.com/docs/platform-‐‑objects/entities h5ps://dev.twi5er.com/docs/tweet-‐‑entities h5ps://dev.twi5er.com/docs/tco-‐‑url-‐‑wrapper

Entities •  Run o  oscon2012_entities.py •  Inspect hashtags, urls et al

Places •  attributes •  bounding_box •  Id (as a string!) •  country •  name h5ps://dev.twi5er.com/docs/platform-‐‑objects/places h5ps://dev.twi5er.com/docs/about-‐‑geo-‐‑place-‐‑a5ributes

Places •  Can search for tweets near a place like so: •  Get latlong of conv center [45.52929,-‐122.66289] o  Tweets near that place •  Tweets near San Jose [37.395715,-‐122.102308] •  We will not see further here. But very useful

Timelines •  Collections of tweets ordered by time •  Use max_id & since_id for navigation h5ps://dev.twi5er.com/docs/working-‐‑with-‐‑timelines

Other Objects & APIs •  Lists •  Notiﬁcations •  Friendships/exists to see if one follows the other

Followers Twitter Platform Friends Are Followed By Objects Follow Users Status Update @ user_mentions Entities embed urls Temporally Tweets embe d Ordered media TimeLine # Places hashtags h5ps://dev.twi5er.com/docs/platform-‐‑objects

Hands-‐‑on Exercise (15 min) •  Setup environment – slide #14 •  Sanity Check Environment & Libraries o  oscon2012_open_this_ﬁrst.py o  oscon2012_rate_limit_status.py •  Get objects (show calls) o  Lookup users by screen_name -‐ oscon12_users.py o  Lookup users by id -‐ oscon12_ﬁrst_20_ids.py o  Lookup tweets -‐ oscon12_tweets.py o  Get entities -‐ oscon12_entities.py •  Inspect the results •  Explore a little bit •  Discussion

Twi5er APIs

Twitter API Near-realtime, High Volume Follow users,Core Data, REST Streaming topics, dataCore Twitter mining Objects Public Streams Seach & User Streams Trend Twitter Twitter Site Streams REST Search Firehose Build Proﬁle Keywords Create/Post Tweets Speciﬁc User Reply Trends Favorite, Re-‐‑tweet Rate Limit : Rate Limit : 150/350 Complexity & Frequency

Twi5er REST API •  https://dev.twitter.com/docs/api •  What we were doing were the REST API •  Request-‐Response •  Anonymous or OAuth •  Rate Limited : o  150/350

Twi5er Trends •  oscon2012-‐trends.py •  Trends/weekly, Trends/monthly •  Let us run some examples o  oscon2012_trends_daily.py o  oscon2012_trends_weekly.py •  Trends & hashtags o  #hashtag euro2012 o  http://hashtags.org/euro2012 o  http://sproutsocial.com/insights/2011/08/twitter-‐hashtags/ o  http://blog.twitter.com/2012/06/euro-‐2012-‐follow-‐all-‐action-‐on-‐pitch.html o  Top 10 : http://twittercounter.com/pages/100, http://twitaholic.com/

Brand Rank w/ Twi5er •  Walk Through & results of following o  oscon2012_brand_01.py •  Followed 10 user-‐brands for a few days to ﬁnd growth •  Brand Rank o  Growth of a brand w.r.t the industry o  Surge in popularity – could be due to –ve or +ve buzz. Need to understand & correlate using Twitter APIs & metrics •  API : url=https://api.twitter.com/1/users/ lookup.json •  payload={"screen_name":"miamiheat,okcthunder,n ba,uefacom,lovelaliga,FOXSoccer,oscon,clouderati, googleio,OReillyMedia"}

Brand Rank w/ Twi5er Clouderati is very stable

Brand Rank w/ Twi5er Tech Brands •  Google I/O showed a spike on 6/27-‐ 6/28 •  OReillyMedia shares some spike •  Looking at a few days worth of data, our best inference is that “oscon doesn’t track with googleio” •  “Clouderati doesn’t track at all”

Brand Rank w/ Twi5er World of Soccer •  FOXSoccer,UEFAcom track each other The numbers seldom decrease. So calculating –ve velocity will not work OTOH, if you see a –ve velocity, investigate

Brand Rank w/ Twi5er World of Basketball •  NBA, MiamiHeat, okcthunder track each other •  Used % than absolute numbers to compare •  The hike on 7/6 to 7/10 is interesting.

Brand Rank w/ Twi5er Rising Tide … •  For some reason, all numbers are going up 7/6 thru 7/10 – except for clouderati! •  Is a rising (Twitter) tide lifting all (well, almost all) ?

Trivia : Search API •  Search(search.twitter.com) o  Built by Summize which was acquired by Twitter in 2008 o  Summize described itself as “sentiment mining”

Search API •  Very simple o  GET http://search.twitter.com/search.json?q=<blah> •  Based on a search criteria •  “The Twitter Search API is a dedicated API for running searches against the real-time index of recent Tweets” •  Recent = Last 6-‐9 days worth of tweets •  Anonymous Call •  Rate Limit o  Not No. of calls/hour, but Complexity & Frequency h5ps://dev.twi5er.com/docs/using-‐‑search h5ps://dev.twi5er.com/docs/api/1/get/search

Search API •  Filters o  Search URL encoded o  @ = %40, #=%23 o  emoticons :) and :(, o  http://search.twitter.com/search.atom?q=sometimes+%3A) o  http://search.twitter.com/search.atom?q=sometimes+%3A( •  Location Filters, date ﬁlters •  Content searches

Streaming API •  Not request response; but stream •  Twitter frameworks have the support •  Rate Limit : Upto 1% •  Stall warning if the client is falling behind •  Good Documentation Links o  https://dev.twitter.com/docs/streaming-‐apis/connecting o  https://dev.twitter.com/docs/streaming-‐apis/parameters o  https://dev.twitter.com/docs/streaming-‐apis/processing

Firehose •  ~ 400 million public tweets/day •  If you are working with Twitter ﬁrehose, I envy you ! •  If you hit real limits, then explore the ﬁrehose route •  AFAIK, it is not cheap, but worth it

API Best Practices 1.  Use JSON 2.  Use user_id than screen_name o  User_id is constant while screen_name can change 3.  max_id and since_id o  For example direct messages, if you have last message use since_id for search o  max_id how far to go back 4.  Cache as much as you can 5.  Set the User-‐Agent header for debugging I have listed a few good blogs that have API best practices, in the reference section, at the end of this presentationThese are gathered from various books, blogs & other media, I used for this tutorial. See Reference(at the end) for the sources

Twitter API Near-realtime, High Volume Follow users,Core Data, REST Streaming topics, dataCore Twitter mining Objects Public Streams Seach & User Streams Trend Twitter Twitter Site Streams REST Search Firehose Build Proﬁle Questions ? Keywords Create/Post Tweets Speciﬁc User Reply Trends Favorite, Re-‐‑tweet Rate Limit : Rate Limit : 150/350 Complexity & Frequency

Part II SNA Part IITwitter Network Analysis

2. Store 3. Transform & 1. Collect Analyze the Validate Dataset & . Keep don’t Tip: 3 simple; re-crawl/refresh a schem afrai d to be for mMost important & transthe ugliest slide in this deck ! as lem ent , 1. Imp ipeline 4. Model Tip: age d p nolith 5. Predict, & a st r a mo Reason neve Recommend & Visualize

Trivia •  Social Network Analysis originated as Sociometry & the social network was called a sociogram •  Back then, Facebook was called SocioBinder! •  Jacob Levi Morano, is considered the originator o  NYTimes, April 3, 1933, P. 17

Twi5er Networks-‐‑Deﬁnitions •  Nodes o  Users o  #tags •  Edges o  Follows o  Friends o  @mentions o  #tags •  Directed

Twi5er Networks-‐‑Deﬁnitions •  In-‐degree o  Followers •  Out-‐Degree o  Friends/Follow •  Centrality Measures •  Hubs & Authorities o  Hubs/Directories tell us where Authorities are o  “Of Mortals & Celebrities” is more “Twitter-‐style”

Twi5er Networks-‐‑Properties M•  Concepts From Citation N Networks K J o  Cocitation L I •  Common papers that cite a paper A •  Common Followers B G o  C & G (Followed by F & H) C H o  Bibliographic Coupling •  Cite the same papers D F •  Common Friends (i.e. follow same E person) o  D, E, F & H

Twi5er Networks-‐‑Properties •  Concepts From Citation Networks M o  Cocitation N •  Common papers that cite a paper K •  Common Followers J L o  C & G (Followed by F & H) I o  Bibliographic Coupling A •  Cite the same papers B G •  Common Friends (i.e. follow same person) o  D, E, F & H follow C o  H & F follow C & G H C •  So H & F have high coupling D •  Hence, if H follows A, we can F recommend F to follow A E

Twi5er Networks-‐‑Properties •  Bipartite/Aﬃliation Networks o  Two disjoint subsets o  The bipartite concept is very relevant to Twitter social graph o  Membership in Lists •  lists vs. users bipartite graph o  Common #Tags in Tweets •  #tags vs. members bipartite graph o  @mention together •  ? Can this be a bipartite graph •  ? How would we fold this ?

Other Metrics & Mechanisms •  Kronecker Graphs Models o  Kronecker product is a way of generating self-‐similar matrices o  Prof.Leskovec et al deﬁne the Kronecker product of two graphs as the Kronecker product of their adjacency matrices o  Application : Generating models for analysis, prediction, anomaly detection et al •  Erdos-‐Renyl Random Graphs o  Easy to build a Gn,p graph o  Assumes equal likelihood of edges between two nodes o  In a Twitter social network, we can create a more realistic expected distribution (adding the “social reality” dimension) by inspecting the #tags & @mentions •  Network Diameter •  Weak Ties •  Follower velocity (+ve & –ve), Association strength o  Unfollow not a reliable measure o  But an interesting property to investigate when it happens Not covered here, but potential for an encore !Ref: Jure Leskovec: Kronecker Graphs, Random Graphs

Twi5er Networks-‐‑Properties •  Twitter != LinkedIn, Twitter != Facebook•  Twitter Network == Interest Network•  Be cognizant of the above when you apply traditional network properties to Twitter •  For example, o  Six degrees of separation doesnt make sense (most of the time) in Twitter – except may be for Cliques o  Is diameter a reliable measure for a Twitter Network ? •  Probably not o  Do cut sets make sense ? •  Probably not o  But citation network principles do apply; we can learn from cliques o  Bipartite graphs do make sense

Cliques (1 of 2) •  “Maximal subset of the vertices in an undirected network such that every member of the set is connected by an edge to every other” •  Cohesive subgroup, closely connected •  Near-‐cliques than a perfect clique (k-‐plex i.e. connected to at least n-‐k others) •  k-‐plex clique to discover sub groups in a sparse network; 1-‐plex being the perfect clique Ref: Networks, An Introduction-‐‑Newman

Cliques (2 of 2) •  k-‐core – at least k others in the subset; (n-‐k)-‐plex •  k-‐clique – no more than k distance away o  Path inside or outside the subset o  k-‐clan or k-‐club (path inside the subset) •  We will apply k-‐plex Cliques for one of our hands-‐on Ref: Networks, An Introduction-‐‑Newman

Sentiment Analysis •  Sentiment Analysis is an important & interesting work on the Twitter platform o  Collect Tweets o  Opinion Estimation -‐Pass thru Classiﬁer, Sentiment Lexicons •  Naïve Bayes/Max Entropy Class/SVM o  Aggregated Text Sentiment/Moving Average •  I chose not to dive deeper because of time constraints o  Couldn’t do justice to API, Social Network and Sentiment Analysis, all in 3 hrs •  Next 3 Slides have couple of interesting examples

Sentiment Analysis •  Twitter Mining for Airline Sentiment •  Opinion Lexicon -‐ +ve 2000, -‐ve 4800 h5p://www.inside-‐‑r.org/howto/mining-‐‑twi5er-‐‑airline-‐‑consumer-‐‑sentiment h5p://sentiment.christopherpo5s.net/lexicons.html#opinionlexicon

Need I say more ? “A bit of clever math can uncover interes4ng pa7erns that are not visible to the human eye” h5p://www.economist.com/blogs/schumpeter/2012/06/tracking-‐‑social-‐‑media?fsrc=scn/gp/wl/bl/moodofthemarket h5p://www.relevantdata.com/pdfs/IUStudy.pdf

Project Ideas

Interesting Vectors of Exploration 1.  Find trending #tags & then related #tags – using cliques over co-‐#tag-‐citation, which infers topics related to trending topics 2.  Related #tag topics over a set of tweets by a user or group of users 3.  Analysis-‐In/Out ﬂow, Tweet Flow –  Frequent @mention 4.  Find aﬃliation networks by List memberships, #tags or frequent @mentions

Interesting Vectors of Exploration 5.  Use centrality measures to determine mortals vs. celebrities 6.  Classify Tweet networks/cliques based on message passing characteristics –  Tweets vs. Retweets, No of reweets,… 7.  Retweet Network –  Measure Inﬂuence by retweet count & frequency –  Information contagion by looking at diﬀerent retweet network subcomponents – who, when, how much,…

Twi5er Network Graph Analysis An Example

Analysis Story Board •  @clouderati is a popular cloud related Twitter account •  Goals: o  Analyze the social graph characteristics of the users who are following the account In this •  Dig one level deep, to the followers & friends, of the tutorial followers of @clouderati o  How many cliques ? How strong are they ? o  Does the @mention support the clique inferences ? For you to o  What are the retweet characteristics ? explore !! o  How does the #tag network graph look like ?

Twi5er Analysis Pipeline Story Board Stages, Strategies, APIs & Tasks Stage 4 Stag o  e 5 o  Get & Store User details For e (distinct user list) follo ach @c o  w loud o  Unroll Find er erat frie i inte nd=f rsec o tion llower Note: Needed a Note: Unroll -‐ se stage took time t command buﬀer to manage scale & missteps (~980,000 users) Stage 3 Stage 6 raph s ocial g heory o  Create twork t ne o  Get distinct user list o  Apply ues & other applying the liq o  Infer c s set(union(list)) operation tie proper

@clouderati Twi5er Social Graph •  Stats (Retrospect after the runs): o  Stage 1 •  @clouderati has 2072 followers o  Stage 2 •  Limiting followers to 5,000 per user o  Stage 3 •  Digging 1st level (set union of followers & friends of the followers of @clouderati) explodes into ~980,000 distinct users o  MongoDB of the cache and intermediate datasets ~10 GB o  The database was hosted at AWS (Hi Mem XLarge – m2.xlarge ), 8 X 15 GB, Raid 10, opened to Internet with DB authentication

Code & Run Walk Through o  Code: §  oscon_2012_user_list_spider_01.py o  Challenges: Stage 1 §  Nothing fancy §  Get the record and store o  Get @clouderati Followers o  Store in MongoDB §  Would have had to recurse through a REST cursor if there were more than 5000 followers §  @clouderati has 2072 followers o  Interesting Points:

Code & Run Walk Through o  Code: §  oscon_2012_user_list_spider_02.py §  oscon_2012_twitter_utils.py §  oscon_2012_mongo.py §  oscon_2012_validate_dataset.py o  Challenges: §  Multiple runs, errors et al ! Stage 2 o  Interesting Points: §  Set operation between two mongo collections for restart buﬀer o  Crawl 1 level deep §  Protected users, some had 0 followers, or 0 friends o  Get friends & followers §  Interesting operations for validate, re-‐crawl and refresh o  Validate, re-‐crawl & refresh §  Added “status_code” to diﬀerentiate protected users §  {$set: {status_code: 401 Unauthorized,401 Unauthorized}} §  Getting friends & followers of 2000 users is the hardest (or so I thought, until I got through the next stage!)

Validate-‐‑Recrawl-‐‑Refresh Logs •  pymongo version = 2.2 •  Connected to DB! o  1st run – 132 bad records •  … o  This is the classic Erlang-‐style •  2075 supervisor •  Error Friends : <type exceptions.KeyError> o  The crawl continue on transport errors •  4ff3cd40e5557c00c7000000 -‐ none has 2072 followers & 0 friends •  Error Friends : <type exceptions.KeyError> without worrying about retry •  o  Validate will recrawl & refresh as 4ff3a958e5557cfc58000000 -‐ none has 2072 followers & 0 friends •  Error Friends : <type exceptions.KeyError> needed •  4ff3ccdee5557c00b6000000 -‐ none has 2072 followers & 0 friends •  4ff3d3b9e5557c01b900001e -‐ 371187804 has 0 followers & 0 friends •  4ff3d3d8e5557c01b9000048 -‐ 63488295 has 155 followers & 0 friends •  4ff3d3d9e5557c01b9000049 -‐ 342712617 has 0 followers & 0 friends •  4ff3d3d9e5557c01b900004a -‐ 21266738 has 0 followers & 0 friends •  4ff3d3dae5557c01b900004b -‐ 204652853 has 0 followers & 0 friends •  … •  4ff475cfe5557c1657000074 -‐ 258944989 has 0 followers & 0 friends •  4ff475d3e5557c165700007d -‐ 327286780 has 0 followers & 0 friends •  Looks like we have 132 not so good records •  Elapsed Time = 0.546846

Code & Run Walk Through o  Code: §  oscon2012_analytics_01.py Stage 3 o  Challenges: o  Figure out the right Set operations o  Get distinct user list applying the set(union(list)) operation o  Interesting Points: §  973,323 unique users ! §  Recursively apply set union over 400,00 lists §  Set operations took slightly more than a minute

Code & Run Walk Through o  Code: §  oscon2012_analytics_01.py (focus on cmd string creation) §  oscon2012_get_user_info_01.py §  oscon2012_unroll_user_list_01.py §  oscon2012_unroll_user_list_02.py Stage 4 o  Challenges: o  Get & Store User details §  Where do I start ? (distinct user list) •  In the next few slides o  Unroll §  Took me a few days to get it right (along with my daily job!) §  Unfortunately I did not employ parallelism & didn’t use my MacPro with 32 GB memory. So the runs were long §  But learned hard lessons on check point & restart o  Interesting Points: §  Tracking Control Numbers §  Time … Marathon unroll run 19:33:33 !

Twi5er @ scale Pa5ern •  Challenge: o  You want to get screen names, follower counts and other details for a million users •  Problem: o  No easy REST API o  https://api.twitter.com/1/users/lookup.json will take 100 user_ids and give details •  Solution: o  This is a scalability challenge. Approach it like so o  Create a command buﬀer collection in MongoDB splitting millon user_ids into batches of 100 o  Have a “done” ﬂag initialized to 0 for checkpoint & restart o  After each cmd str is executed, rest “done”:1 o  For subsequent runs, ignore “done”:1. o  Also helps in control number tracking

Control numbers

Control Numbers •  > db.t_users_info.count() •  8122 •  > db.api_str.count({"done":0,"seq_no":{"$lt":8185}},{"seq_no”:) •  63 •  > db.api_str.find({"done":0,"seq_no":{"$lt":8185}},{"seq_no":1}) The collection should have 8185 •  { "_id" : ObjectId("4ff4daeae5557c28bf001d53"), "seq_no" : 5433 } documents •  { "_id" : ObjectId("4ff4daeae5557c28bf001d59"), "seq_no" :o5439 } But it has nly 8122. Where did the rest go ? •  { "_id" : ObjectId("4ff4daeae5557c28bf001d5f"), "seq_no" : 5445 } 63 of them still have done=0 •  8122 + 63 = 8185 ! { "_id" : ObjectId("4ff4daebe5557c28bf001d74"), "seq_no" : 5466 } Aha, mystery solved. •  { "_id" : ObjectId("4ff4daece5557c28bf001d7a"), "seq_no" : 5472 } They fell through the cracks •  Need a catch-‐all final run { "_id" : ObjectId("4ff4daece5557c28bf001d80"), "seq_no" : 5478 } •  { "_id" : ObjectId("4ff4daede5557c28bf001d90"), "seq_no" : 5494 } •  { "_id" : ObjectId("4ff4daefe5557c28bf001daf"), "seq_no" : 5525 }

Day in the life of a Control Number Detective – Run #1 •  Remember : 973,323 users. So, 9734 cmd strings (100 users perstring) •  > > db.api_str.count() •  9831 •  > db.api_str.count({"done":0}) •  239 •  >> db.t_users_info.count() •  9592 •  > > db.api_str.count({"api_str":""}) •  97 •  So we should have 9831 – 97 = 9734 records •  The second run should generate 9734-‐9592 = 142 calls (i.e. 350-‐142=208 rate-‐limit should remain). Let us see. •  { •  … •  "x-‐ratelimit-‐class": "api_identiﬁed", •  "x-‐ratelimit-‐limit": "350", •  "x-‐ratelimit-‐remaining": "209", •  … •  } •  Yep, 209 left •  >

Day in the life of a Control Number Detective – Run #2 •  Remember : 973,323 users. So, 9734 cmd strings (100 users perstring) •  > db.t_users_info.count() •  { •  9728 •  … •  > db.api_str.count({"api_str":""}) •  "x-‐ratelimit-‐limit": "350", •  97 •  "x-‐ratelimit-‐remaining": "344", •  > db.api_str.count({"done":0}) •  … •  103 •  } •  >9734-‐9728=6, same as 103-‐97 ! •  Yep, 6 more records •  Run once more ! •  > db.t_users_info.count() •  > db.api_str.find({"done":0},{"seq_no":1}) •  9734 •  … •  Good, got 9734 ! •  { "_id" : ObjectId("4ff4dbd4e5557c28bf002e22"), "seq_no" : 9736 } •  { "_id" : ObjectId("4ff4db05e5557c28bf001f47"), "seq_no" : 5933 } •  { "_id" : ObjectId("4ff4db8be5557c28bf0028f6"), "seq_no" : 8412 } •  { "_id" : ObjectId("4ff4dba2e5557c28bf002a8c"), "seq_no" : 8818 } •  { "_id" : ObjectId("4ff4dbaee5557c28bf002b69"), "seq_no" : 9039 } •  { "_id" : ObjectId("4ff4dbb8e5557c28bf002c1c"), "seq_no" : 9218 } •  … Professor Layton would be proud ! In fact, I have all the four & plan to spend sometime with them & Laphraig !

Monitor runs & track control numbers Unroll run 8:48 PM to ~4:08 PM next day !

Track error & the document numbers

Code & Run Walk Through o  Code: §  oscon2012_ﬁnd_strong_ties_01.py §  oscon2012_social_graph_stats_01.py Stage 5 o  Challenges: o  For each @clouderati §  None. Python set operations made this easy follower o  Find friend=follower -‐ set o  Interesting Points: intersection §  Even at this scale, single machine is not enough §  Should have tried data parallelism •  This task is well suited to leverage data parallelism as it is commutative & associative •  Was getting invalid cursor error from MongoDB •  So had to do the updates in two steps

Code & Run Walk Through o  Code: §  oscon2012_ﬁnd_cliques_01.py o  Challenges: Stage 6 o  Lots of good information hidden in the data ! o  Create social graph o  Apply network theory o  Memory ! o  Infer cliques & other properties o  Interesting Points: o  Graph, List & set operations o  networkx has lots of interesting graph algorithms o  Collections.Counter to the rescue

Twi5er Social Graph Analysis of @clouderati o  2072 Followers; 973,323 unique users one level down w/ followers/friends trimmed at 5,000 o  Strong ties o  follower=friend o  235,697 users, 462, 419 edges o  501,367 Cliques o  253 unique users 8,906 Cliques w/ > 10 users o  GeorgeReese in 7,973 of them ! See List for 1st 125 o  krishnan 3,446,randy 2,197, joe 1,977, sam 1,937, jp 485, stu 403, urquhart 263,beaker 226, acroll 149, adrian 63, gevaperry 24 o  Of course, clique analysis does not tell us the whole story … Clique Distribution = {2: 296521, 3: 58368, 4: 36421, 5: 28788, 6: 24197, 7: 20240, 8: 15997, 9: 11929, 10: 6576, 11: 1909, 12: 364, 13: 55, 14: 2}

Twi5er Social Graph Analysis of @clouderati Celebrity – very low strong ties Higher Celebrity, low strong ties o  sort by followers vs. sort by strong ties is interesting Medium Celebrity, medium strong ties

Twi5er Social Graph Analysis of @clouderati o  A higher “Strong Ties” number is interesting §  It means a very high follower-‐friend intersection §  Reeves 62%, bgolden 85% o  Bur a high clique with a smaller “Strong ties” show more cohesive & stronger social graph §  eg.Krishnan -‐ 15% friends-‐followers §  Samj – 33%

Twi5er Social Graph Analysis of @clouderati o  Ideas for more Exploration §  Include all followers (instead of stopping at the 5000 cap) §  Get tweets & track @mention §  Frequent @mention shows more stronger ties §  #tag analysis could show some interesting networks

Twitter Tips – A Baker’s Dozen 1.  Twitter APIs are (more or less) congruent & symmetric 2.  Twitter is usually right & simple -‐ recheck when you get unexpected results before blaming Twitter o  I was getting numbers when I was expecting screen_names in user objects. o  Was ready to send blasting e-‐mails to Twitter team. Decided to check one more time and found that my parameter key was wrong-‐screen_name instead of user_id o  Always test with one or two records before a long run ! - learned the hard way3.  Twitter APIs are very powerful – consistent use can bear huge data o  In a week, you can pull in 4-‐5 million users & some tweets ! o  Night runs are far more faster & error-free4.  Use a NOSQL data store as a command buﬀer & data buﬀer o  Would make it easy to work with Twitter at scale o  I use MongoDB The o  Keep the schema simple & no fancy transformation Beg in •  And as far as possible same as the ( json) response The ning A o  Use NOSQL CLI for trimming records et al End s

Twitter Tips – A Baker’s Dozen 5.  Always use a big data pipeline o  Collect - Store - Transform & Analyze - Model & Reason - Predict, Recommend & Visualize o  That way you can orthogonally extend, with functional components like command buffers, validation et al 6.  Use functional approach for a scalable pipeline o  Compose your data big pipeline with well defined granular functions, each doing only one thing o  Don’t overload the functional components (i.e. no collect, unroll & store as a single component) o  Have well defined functional components with appropriate caching, buffering, checkpoints & restart techniques •  This did create some trouble for me, as we will see later7.  Crawl-‐Store-‐Validate-‐Recrawl-‐Refresh cycle o  The equivalent of the traditional ETL o  Validation stage & validation routines are important •  Cannot expect perfect runs •  Cannot manually look at data either, when data is at scale 8.  Have control numbers to validate runs & monitor them o  I still remember control numbers which start with the number of punch cards in the input deck &d then follow that number through the various runs ! o  There will be a separate printout of the control numbers that will be kept in the operations files

Twitter Tips – A Baker’s Dozen 9.  Program defensively o  more so for a REST-based-Big Data-Analytics systems o  Expect failures at the transport layer & accommodate for them 10.  Have Erlang-‐style supervisors in your pipeline o  Fail fast & move on o  Don’t linger and try to ﬁx errors that cannot be controlled at that layer o  A higher layer process will circle back and do incremental runs to correct missing spiders and crawls o  Be aware of visibility & lack of context. Validate at the lowest layer that has enough context to take corrective actions o  I have an example in part 211.  Data will never be perfect o  Know your data & accommodate for it’s idiosyncrasies •  for example: 0 followers, protected users, 0 friends,…

Twitter Tips – A Baker’s Dozen 12.  Check Point frequently (preferably after ever API call) & have a re-‐startable command buﬀer cache o  See a MongoDB example in Part 213.  Don’t bombard the URL o  Wait a few seconds before successful calls. This will end up with a scalable system, eventually o  I found 10 seconds to be the sweet spot. 5 seconds gave retry error. Was able to work with 5 seconds with wait & retry. Then, the rate limit started kicking in ! 14.  Always measure the elapsed time of your API runs & processing o  Kind of early warning when something is wrong 15.  Develop incrementally; don’t fail to check “cut & paste” errors

Twitter Tips – A Baker’s Dozen 16.  The Twitter big data pipeline has lots of opportunities for parallelism o  Leverage data parallelism frameworks like MapReduce o  But ﬁrst : §  Prototype as a linear system, §  Optimize and tweak the functional modules & cache strategies, §  Note down stages and tasks that can be parallelized and §  Then parallelize them o  For the example project, we will see later, I did not leverage any parallel frameworks, but the opportunities were clearly evident. I will point them out, as we progress through the tutorial17.  Pay attention to handoﬀs between stages o  They might require transformation – for example collect & store might store a user list as multiple arrays, while the model requires each user to be a document for aggregation o  But resist the urge to overload collect with transform o  i.e let the collect stage store in arrays, but then have an unroll/flatten stage to transform the array to separate documents o  Add transformation as a granular function – of course, with appropriate buffering, caching, checkpoints & restart techniques 18.  Have a good log management system to capture and wade through logs

Twitter Tips – A Baker’s Dozen 19.  Understand the underlying network characteristics for the inference you want to make o  Twitter Network != Facebook Network , Twitter Graph != LinkedIn Graph o  Twitter Network is more of an Interest Network o  So, many of the traditional network mechanisms & mechanics, like network diameter & degrees of separation, might not make sense o  But, others like Cliques and Bipartite Graphs do

Twitter Gripes 1.  Need more rich APIs for #tags o  Somewhat similar to users viz. followers, friends et al o  Might make sense to make #tags a top level object with it’s own semantics 2.  HTTP Error Return is not uniform o  Returns 400 bad Request instead of 420 o  Granted, there is enough information to figure this out3.  Need an easier way to get screen_name from user_id 4.  “following” vs. “friends_count” i.e. “following” is a dummy variable. o  There are a few like this, most probably for backward compatibility5.  Parameter Validation is not uniform o  Gives “404 Not found” instead of “406 Not Acceptable” or “416 Range Unacceptable” 6.  Overall more validation would help o  Granted, it is more of growing pains. Once one comes across a few inconsistencies, the rest is easy to figure out

Thanks To these Giants …

I had a good time researching & preparing for this Tutorial. I hope you learned a few new things & have a few vectors to follow

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The Art of Social Media Analysis with Twitter & Python

by ksankar on Jul 08, 2012

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The Art of Social Media Analysis with Twitter & Python Presentation Transcript