Username Lookup Service
- Global Load Balancer decides Region
- Local Load balancer routes to the application server
- Application server has in-memory data structure for bloom filter
- If bloom filter says username exists (Maybe-Yes)
- Check the Redis Cache
- If Cache hit
- save to bloom filter
- Respond with Yes
- else
- Go to Distributed DB like Cassandra or Amazon DynamoDB
- Return DB Response
- else (Firm-No)
- Respond with a firm No
Strategies compared
| Strategy | Memory | Time | Benefits |
|---|---|---|---|
| Redis HashMap | High | O(1) | Exact Match |
| Trie | Moderate | O(m), m = longest word length | Prefix matching |
| B/B+ Tree | Moderate | O(logm) | Range based queries |
| Bloom Filter | Low | O(k), k = bit array size | Exact Match |