why? instagram is the biggest vangav backend template designed for big scale and covering all the core features/utilities: service oriented architecture, worker service, multi-entry-point api, multi-keysapce database, oauth 2, facebook authentication, facebook graph api, rest jobs, periodic jobs, vangav mighty, push notifications, logging, analytics, client generator, test service, bots service, ...

• instagram, instagram dispense, instagram jobs, instagram worker and instagram dash board services work together and are generated using vangav backend

• instagram test is used to test the services above and instagram bots is used to simulate normal users' behavior; both services are generated using vangav backend

• vangav backend tutorials

• signup/login using email/facebook
• request authentication using oauth 2
• fetching/updating users' information
• follow/unfollow and get followers/following lists for users
• posting photos
• get posts by feed and by user
• interacting with posts (like, comment, ...)
• get top users/posts
• searching for users
• get server time

• is a helper service for instagram; responsible for distributing posted photos to followers (because on photo can be posted to tens of millions of followers; such an expensive operation should be distributable and shouldn't overload the main service)

• crawls for failed jobs in the database to retry executing them (e.g.: a dispense job, ...)
• uses vangav mighty to update top users (per geo grid, per country and world wide) every week
• uses vangav mighty to update top posts (per geo grid, per country and world wide) every day

• writes logs and analytics in the database
• sends push notifications (ios and android)

• handles fetching logs and analytics for system admin

• has a full-coverage test for all the services above

• simulates incremental usage behavior from many cities around the world with some celebrity users

• this service is based on vangav backend's instagram template
• this service has the 90+% of the vangav backend's generated code + the 10-% of the logic code needed to complete the service

1. for first timers - follow the steps in the system requirements tutorial
2. for first timers - follow the steps in the workspace initialization tutorial
3. download instagram, instagram dispense, instagram jobs, instagram worker and instagram dash board projects (from the green clone or download button) inside the workspace directory created previously (my_services) and unzip them
4. rename unzipped directories, remove the -master from their names
5. in the terminal cd to vos_instagram/cassandra/cql/
6. execute ./_start_cassandra.sh to start cassandra
7. cd to vos_instagram/cassandra/cql/drop_and_create/
8. execute the commands ./_execute_cql.sh ig_....cql to initialize the services' database tables; repeat this step for all the .cql files
9. cd to vos_instagram_worker and execute ./_run.sh to start the instagram worker service on port 8000
10. cd to vos_instagram_dispense and execute ./_run.sh 3000 to start the instagram dispense service on port 3000
11. cd to vos_instagram_jobs and execute ./_run.sh 4000 to start the instagram jobs service on port 4000
12. cd to vos_instagram_dash_board and execute ./_run.sh 5000 to start the instagram dash board service on port 5000
13. cd to vos_instagram and execute ./_run.sh to start the instagram service on port 9000
14. from your prefered client (we recommned postman) start trying the service; refer to the features and service references sections for reference

• at the end to stop the services: press control + d in the terminal session where each service was started in (9, 10, 11, 12 and 13)
• to stop cassandra: execute ps auwx | grep cassandra to get cassandra's (pid) then kill -9 (pid) to stop cassandra

• follow the following steps to import the downloaded backend service in eclipse

1. cd to the service's directory and execute the ./_eclipsify.sh script
2. file > import > general > existing projects into workspace > next > set "select root directory" to my_services > under projects make sure that vos_calculate_sum is selected > finish
3. double check the java version used for compiling the project: right click the project > properties > java compiler > enable project specific settings > compiler compliance level > 1.7 or 1.8

• generate multiple services (main + dispense + jobs + worker + dash board) to work together in a service oriented architecture
• generate a multi-keyspace database
• oauth 2 and facebook authentication
• facebook graph api
• rest jobs
• periodic jobs
• vangav mighty
• push notifications
• logging
• analytics
• client generator
• test and bots services

• this section lists the 10-% code added after vangav backend generated 90+% of the code

• following are the error codes of instagram services

• instagram, instagram dispense, instagram jobs, instagram worker, instagram dash board, instagram test and instagram bots services has no connection with Instagram Inc.; these services are just a vangav backend template to demonstrate using some features/utilities in the context of photo sharing apps
• the "instagram" name is used for users to easier understand the services' design, features and source code