robinliubin/cassandraRESTapi

event flow using Azure cosmo DB of Cassandra and Flask as REST API server

page_type	languages
assignment from Unity	python cassandra

player session service using Python + Cassandra API on Azure

design and implement a player session service which consumes events and provides metrics about players sessions. Each user will generate two events, one start event when the session starts and one end event when session is finished. When both events have been received the session is considered complete. Service is expected to handle massive amount of sessions.

requirements

• Use Python and Cassandra

• All endpoints are REST APIs

  tested with postman for GET and POST

• API for receiving event batches (1-10 events / batch)

  POST will take 1-many events as input in json format, and return 200OK and string "POST success"

• API for fetching last 20 complete sessions for a given player

  GET will take player_id as input in json format, and return 20 complete sessions

• Data older than 1 year should be discarded

  INSERT using TTL of 865400 seconds, so data with 1 years old is automatically cleaned up.

Running this sample

1. Run python create_DB.py in a terminal to create data model schema in Azure cassandra DB, ONLY ONCE
2. Run python restAPI.py in a terminal to start Flask to take GET and POST

About the code

test the API with below curl code or POSTMAN

• GET json body format:

curl --location --request GET 'http://127.0.0.1:5000/?Content-Type=application/json&Accept=application/json' \
--header 'Content-Type: application/json' \
--data-raw '{
    "player_id":"d6313e1fb7d247a6a034e2aadc30ab3f"
}'

• POST json body format:

curl --location --request POST 'http://127.0.0.1:5000/?Content-Type=application/json' \
--header 'Content-Type: application/json' \
--header 'Accept: application/json' \
--data-raw '{
    "rows":[
            {"player_id": "d6313e1fb7d247a6a034e2aadc30ab10", "country": "SK", "event": "start", "session_id": "3346a60a-0989-4041-aacc-cf6ff44bd151", "ts": "2016-12-02T05:36:16"},
            {"player_id": "d6313e1fb7d247a6a034e2aadc30ab22", "country": "UK", "event": "start", "session_id": "3346a60a-1089-4041-aacc-cf6ff44bd177", "ts": "2016-12-02T05:37:16"},
            {"player_id": "d6313e1fb7d247a6a034e2aadc30ab20", "country": "SK", "event": "start", "session_id": "3346a60a-0989-4041-aacc-cf6ff44bd152", "ts": "2016-12-03T05:36:16"},
            {"player_id": "d6313e1fb7d247a6a034e2aadc30ab32", "country": "UK", "event": "start", "session_id": "3346a60a-1089-4041-aacc-cf6ff44bd178", "ts": "2016-12-03T05:37:16"},
            {"player_id": "d6313e1fb7d247a6a034e2aadc30ab40", "country": "SK", "event": "start", "session_id": "3346a60a-0989-4041-aacc-cf6ff44bd153", "ts": "2016-12-04T05:36:16"},
            {"player_id": "d6313e1fb7d247a6a034e2aadc30ab42", "country": "UK", "event": "start", "session_id": "3346a60a-1089-4041-aacc-cf6ff44bd179", "ts": "2016-12-04T05:37:16"}
    ]
}'