I am migrating an RDS postgres from one account to another account using pg_dump/restore + DMS CDC for ongoing replication. For the backout plan i came across bi-directional replication.
is there any other method available with minimum to no downtime for the backout? please advise
PG 11.13
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I have several postgres databases which need to be replicated as-is to a single aws redshift.
We have currently set up DMS services to the same. However, we keep encountering issues such as source database full, large column issues and most importantly the issue in DMS when new columns with defaults are added on postgres databases(This does not replicate with ongoing replication)
So, are there any other ways that we can set up this ongoing replication?
I would like to backup every single PostgreSql database of my AWS RDS Cluster (Aurora DB Engine). Are there some managed tools (like Veeam or N2WS) or best practices, how to backup and restore a single database or schema from AWS S3?
Many thanks
You can use automatic backup combined with manual backup for Aurora PostgreSql database. For automatic backup, the max retention period is 35 days, and support any point in time restore and recovery. However, if you need a backup beyond the backup retention period (35 days), you can also take a snapshot of the data in your cluster volume.
If you use third-party tools, such as Veeam, it will also invoke AWS RDS snapshot API to take the backup, so the underly mechanism is the same.
You can also use the pg_dump utility for backing up the RDS for PostgreSQL database, and run pg_dump on read replica to minimize the performance impact to the primary database.
We want to migrate an external postgresql database into amazon RDS however for some time we need to keep both of them working and in sync. I have found ways of doing it but only with RDS being the master and not the Slave. Is there a good and viable solution which could help us?
There is AWS service Database Migration Service which can be used to migrate external databases to Amazon AWS RDS.
https://docs.aws.amazon.com/dms/latest/userguide/Welcome.html
It supports postgresql 9.4 and higher.
There are different task types and you need to use Ongoing Replication to keep them sync.
https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Task.CDC.html
To setup that task you need to enable Logical Replication for source database
I have a requirement of replicate data from AWS RDS Postgres(9.6) Database to On-Premise Postgres(9.5) Database. I have found stuff about replication from On-premise to On-premise. But How can we implement it for AWS RDS to On-premise?
I do this using Bucardo.
Check-out this: https://bucardo.org/Bucardo/
With Bucardo you can replicate RDS postgres instance to a slave postgres present somewhere, only configuring slave, so without the needs to configure RDS stuff.
Also you can do this with zero downtime.
Anyway I am not sure this will work using different versions of Postgresql. You should use same version if possible. I tested it with 9.4.x and it is working.
UPDATE
I can confirm that this is working also using different version of Postgres, for example I was able to replicate with these versions:
AWS RDS postgresql 9.4.x
On-premise postgresql 9.6.x
http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_PostgreSQL.html#PostgreSQL.Concepts.General.FeatureSupport.LogicalReplication
Beginning with PostgreSQL version 9.4, PostgreSQL supports the
streaming of WAL changes using logical replication slots. Amazon RDS
supports logical replication for a PostgreSQL DB instance version
9.4.9 and higher and 9.5.4 and higher. Using logical replication, you can set up logical replication slots on your instance and stream
database changes through these slots to a client like pg_recvlogical.
Logical slots are created at the database level and support
replication connections to a single database.
mind possible problems eg https://dba.stackexchange.com/questions/173267/aws-rds-postgres-logical-replication
I am considering using AWS Aurora, however I am concerned for being locked into AWS indefinitely. So I am wondering how difficult it would be to transfer data from Aurora to my own Postgres database.
Thanks!
This is a very valid concern. Firstly, there is no seamless migration like there is from Postgres to Aurora. Following, needs to be considered:
How to do it: You will have to take a dump of your aurora db and then import it into postgres.
Because of 1 above; you cannot have concurrent CURD operations running on your aurora during migration. Hence, you need to shut down all products connecting to your aurora till you migrate to Postgres. Hence, there will be downtime.
Because of 2 ; Depending on size of your DB; it might take few mins ( few GB of data ) to many hours if you have huge DB.
Hence, you need to consider how much data you have and how much downtime you can live with if you want to migrate back to Postgres.