Redis Replication Issue

Question

I have a Redis Master node which will be populated by a master application. Then i will have multiple slaves of this Redis node which might be at different locations geographically. These nodes will be read by apps near to that node.

App1. Slave1

App2. Slave2

Now App1 and App2 are related somehow and I dont want a situation where a particular piece of data is available at Slave1 and not at Slave2.

In other words, i dont want any sync latency. I want the data to be synced down at the same time.

Is it possible that the master pushes the updates to the slaves rather than slaves asking for it.

Answer 1

In other words, i dont want any sync latency. I want the data to be synced down at the same time.

It's impossible. In theory, the consistency can be guaranteed by distributed transaction. Redis (and many NoSQL) doesn't use distributed transaction because of performance concern.

Is it possible that the master pushes the updates to the slaves rather than slaves asking for it.

There is some misunderstanding. In redis, the master DO pushes updates to the slaves. However, this cannot prevent inconsistency (sync latency).