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given a url, should return a shorter and unique alias
when user click the short link, the service will redirect user to the original URLs
link will expired by a standard timestamp
availability
reliable
consistance
write 20M new urls are generated per day
read: write = 100 : 1
user base64(0-9, a-z, A-Z, -, =) to encode the URLs. and encode URLs to a 6-digits key
original URLs 256 bytes, key 6 bytes, expiredTimeStamp 20bytes in total ~ 500bytes
file storage: 20M * 500 bytes ~ 10MB/day
write QPS = 20M / 86400 = ~ 250 url/s
read QPS = 25k url/s
Bandwidth:
Write 250 * 500 bytes = 125 kb/s
read = 25K * 500 bytes = 12.5MB/s
String EncodeURL(string apikey, string originalUrl, DateTime expired_data, String userID = null) return shortern url if succeed
Void DeleteURL(String apikey, String url_key)
urls table
key char[6]
urls char[400]
timestamp datatime
created User: uuid
users table
userID: char[8]
You should identify enough components that are needed to solve the actual problem from end to end. Also remember to draw a block diagram using the diagramming tool to augment your design. If you are unfamiliar with the tool, you can simply describe your design to the chat bot and ask it to generate a starter diagram for you to modify...
User send write request -> Load balance -> application service -> write new generated short URL to database -> add URL to Cache -> start replicate -> return succeed
User send read request -> load balance -> application service -> read cache -> read database -> return original URL -> redirect user to original url
Dig deeper into 2-3 components and explain in detail how they work. For example, how well does each component scale? Any relevant algorithm or data structure you like to use for a component? Also you could draw a diagram using the diagramming tool to enhance your design...
Use No-SQL, this is an read heavy service.
Add Cache to satisfied the low lantency of read requests
single point failed: add multiple service/load balance/ cache/ database
What are some future improvements you would make? How would you mitigate the failure scenario(s) you described above?