Overview:
The current cache time for a device profile entry in Redis is 24 hours. If any changes in the device location take place, they are not updated in Redis cache until 24 hours.
Problem Statement:
Changes to the device profile needs to be a push mechanism from the Device Register API call instead of a pull mechanism after 24 hours. A Kafka event needs to be generated and the RedisUpdater Samza job needs to update the cache entry with relevant details.
Design Flow:
Solution:
Steps:
The DeviceRegister Service writes the device profile details into a device-profile.log file.
device-profile.log{ "statecustomcode": "29", "country": "India", "iso3166statecode": "IN-KA", "device_id": "232455", "uaspec": { "agent": "Chrome", "raw": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.75 Safari/537.36", "system": "Linux", "ver": "68.0.3440.75" }, "city": "Bengaluru", "countrycode": "IN", "state": "Karnataka", "statecode": "KA", "updated_date": 1566383863167, "devicespec": { "os": "Android 6.0", "make": "Motorola XT1706" }, "districtcustom": "", "fcm_token": "asda", "firstaccess": 1565328282703, "statecustomname": "Karnataka", "producer_id": "dev.sunbird.portal" }- Logstash will be configured to read from the log file and push the data into a Kafka as a event.
- RedisUpdater Samza job reads the Kafka event and:
a) If device_id exists in cache, updates the cache.
b) If device_id doesn't exist in cache, creates new entry in cache.