Tweet Tracker
This repository accompanies a presentation made for USC Course 31934, Spring 2016: Web Application Project.
Goal: Examine a traditional three tier web application compared to a stateful web service.
Contained within this repository are two API servers capable of tracking and persisting occurrences of hashtags, and responding with a global statistics counter.
- Three-Tier: A traditional stateless web app delegating all stateful behavior to the database.
- Stateful: A stateful web app leveraging in-process data locality to respond immediately to requests.
Both servers have two routes exposed:
GET /
: Retrieves statistics on all tracked hashtagsPOST /track?hashtag=<name>
: Tracks a usage event of a particular hashtag.
Both servers are backed by a Postgres instance.
Instructions:
- Clone repository, create the database, and ensure both servers can start.
- Benchmark both servers for reading and writing.
- (extra credit) - Generate 100k+ rows and repeat the benchmark.
- Share and discuss results.
Database
Both apps use the same database. Once you have Postgres installed, create a database called tweets
:
createdb tweets
psql -d tweets
create table tweets (id serial primary key, hashtag text not null, created_at timestamp not null);
Starting your web server
cd three_tier
(orcd stateful
)bundle install
bundle exec ruby app.rb
verify the app loads by going to http://localhost:4567/ on your browser
Benchmarking
Once you have a web server running, time to benchmark!
Install wrk
: brew install wrk
# GET '/'
wrk -d10s --timeout 2000 http://localhost:4567/
# POST '/track?hashtag=<insert hashtag>'
wrk -d10s --timeout 2000 -s track.lua http://localhost:4567/
(Extra Credit) Generating Extra Rows
insert into tweets (hashtag, created_at) select 'hashtag_' || (s.i / 100)::text, now() as created_at from generate_series(1,100000) as s(i);