This is a very nice video. Explains the RDS failover simpler. DNS, it seems it acts as an ELB. How does RDS know which AZ to point to in case of a failover (RDS reboot)? Does it somehow ping all AZs? I noticed when we created an RDS we did not specify any, which is recommended for failover RDSs.
You should have tries to insert another row into the table while DNS pointing to the Standby instance. It is not clear if the Standby instance is RO as MSSQL standby DBs, or it is bi-directional sync
Good question and suggestion. Actually when failover happens then secondary becomes primary and you can do both read write on nee primary. Meanwhile if older Primary comes up then it becomes secondary and replication happens automatically. Note that at any moment you can only read and write to primary. Secondary is not available even for a read. For that you can create read replicas which are different than multi-az setup. Hope this clarifies your doubts.
Hey Uday, thanks for your comment and I can’t tell how much satisfaction it brings when some says they want to donate to appreciate the work and I already earned my credit with that :-) May be you could subscribe and share the videos/channel with your friends that should help. Thank you again and Stay safe !!
Sorry if this was obvious and I'm missing it. But is there any reason to have the RDS replica in a different VPC subnet? Why not have it in the same one?
Hi, question is apt however understand that you want to have maximum resiliency and your replica should be in different AZ for that. Subnet is bound to single AZ and hence different subnet is required.
Hey Dhanraj, thanks for reaching out. Actually the course is temporarily un-available as one image needs to be replaced. Should be available by tomorrow.
thank you very much for the very useful video, i have a question please. what shall we do to get back to the source db from standby replica. Thank you again
AWS automatically tries to recover the master and if successful then it will set the original master as replica when failover happens. So nothing needs to be done.
@@AWSwithChetan awesome, thanks for quick reply. If I wanna test my read replica in a cross region and want to get back to my master db. How do i test it? change the readonly paramter to 0 on readreplica and reboot the master db with checking the failover and then do the other way around to get back to master db. Or there is another simpler way. Thank you again for quick reply
