educative.io

Missing a lot of things

Courses
,
#1

Hi

This is the one topic that is far below expectations.I gained nothing from this instead spending hours of effort. Let us say i propose this to someone in interview. I cannot defend it. It will create negative impact instead positive. Lot of missing points here:

  1. So many message queue?
  2. Why request queue is needed?
  3. If a client comes after a month, then message queue might have destroyed updates, how will it get?There is no communication between client and sync servers?
  4. You are saying sync server should send small diff to client as more data is there and all, but sync server should only tell this is all updated, and then client should goto block and ask new data.
  5. How concurrent updates will be handled?
  6. Who will upload to cloud? If watcher is monitoring the workspace, then for any updates ,will it inform chunker?Does that mean watcher knows chunking part also?
    and the list goes on…
    …

Thanks,
Rahul

#2

For future doubt reader,

Notification service

This is a separate service dedicated to monitoring if changes have been made to Dropbox accounts. No file data or metadata is stored or transferred here. Each client establishes a long poll connection to the notification service and waits. When a change to any file in Dropbox takes place, the notification service signals a change to the relevant client(s) by closing the long poll connection. Closing the connection signals that the client must connect to the Metadata Servers securely to synchronise any changes.

Link : https://www.dropbox.com/business/trust/security/architecture

Which means, there is no such concept of queues, client poll at regular intervals and as soon as any updates are there, server has a request from client.it updates and send,

but for file uploading we can have queue,we can receive a chunk and add it to queue, to do compression and all stuff that it does not mention

So what if a client is offline, he can always ask server when it comes online,this is my current state, send me updates.Queues are not scalable at this scale

3 Likes