CODEWITHSUNDEEP
redisconsistency
chenwh
chenwh

Reputation: 13

how to ensure data consistency between master and slave in redis

I make a program that can convert numbers to some Serial numbers by some rules and check if Serial numbers is used. And I use redis to do the check work.

First, get num1 in slave. when result is not nil , it means serial number is used , so return 'used'.

Second, if result is nil, set num1 in master and return 'new' (once return , the nums mean 'used')

The problem is that master will crash before it finish the process of sync with slave , so the number maybe not in slave. At this time get num1 in slave , it return 'new',but the num1 is used.

how to ensure data consistency between master and slave in redis?

Upvotes: 1

Views: 2528

Answers (2)

Itamar Haber
Itamar Haber

Reputation: 49942

Read about the WAIT command - it allows you to specify the number of slaves that were updated with the most recent change before taking further action.

Upvotes: 3

davissp14
davissp14

Reputation: 775

Redis uses asynchronous replication and it is not possible to ensure the slave actually received a given write. There will always be a window for data loss.

Replication Docs

Upvotes: 1

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