Faculty of Mathematics University of Belgrade Google App

Faculty of Mathematics, University of Belgrade Google App Engine and Java Application: Clustering Internet search results for a person 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs

Google App Engine • • • Web application hosting service Designed for real-time dynamic apps Many simultaneous users Scalable Paying resources monthly Free account (5 million page views a month) 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 2/14

Sandboxing • App can only read its own files • App cannot manipulate environment variables • App cannot access network facilities • Distributing request non-deterministically • Consequence: run multiple apps on the same server, or one app on multiple servers safely 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 3/14

Architecture overview 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 4/14

Features • The static file servers • The Datastore – Not join-query database – Most resembling to object database • Entities and properties – Entity has 1. . * properties – Not to be confused with rows in RDBMS 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 5/14

Features • Queries and indexes – Index in made for every simple query – Query performance affected only by the size of the result set • Transactions – Optimistic concurrency control – Entity groups (entities updated in one trans. ) • Services: memcache, URL fetch , Mail, … 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 6/14

App Engine’s request handling 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 7/14

Building applications 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 8/14

App engine dashboard 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 9/14

App engine dashboard 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 10/14

Clustering search results 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 11/14

Clustering search results 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 12/14

EC 2 vs GAE vs Azure 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 13

EC 2 vs GAE vs Azure 23. 11. 2020. Aleksandar Kartelj kartelj@matf. bg. ac. rs 14

Thank you. Aleksandar Kartelj Faculty of Mathematics, University of Belgrade kartelj@matf. bg. ac. rs www. matf. bg. ac. rs/~kartelj