brandon/oam
1
0
Fork 0
mirror of https://gitea.com/mcereda/oam.git synced 2026-02-09 05:44:23 +00:00
Code Issues Packages Projects Releases Wiki Activity

fix(kb/aws/rds): confirm no (perceived) downtime for storage type and multi-az conversions

Browse Source
This commit is contained in:
Michele Cereda
2025-09-29 12:53:13 +02:00
parent 7bf0325b92
commit e1295c09bb
1 changed files with 19 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
knowledge base/cloud computing/aws/rds.md
View File

@@ -214,9 +214,9 @@ Use one of the following methods:
[DMS][what is aws database migration service?]<br/> [DMS][what is aws database migration service?]<br/>
This **should** require **minimal** downtime. This **should** require **minimal** downtime.
RDS instances using GP2 storage can convert their volumes to GP3.<br/> RDS instances using GP2 storage can convert their volumes to GP3 just by modifying the DB instance.<br/>
There seems to be no downtime associated with this operation, but performances **will** be impacted until the process This operation does cause downtime, but performances **will** be impacted until the process ends and the change **will**
ends and the change will trigger [storage optimization].<br/> trigger [storage optimization] for the instance.<br/>
Refer [Changing RDS storage from gp2 to gp3]. Refer [Changing RDS storage from gp2 to gp3].
### Storage optimization ### Storage optimization
@@ -547,20 +547,6 @@ system maintenance, and helps protect the database against DB instance failure a
> One **cannot** use the standby replica to serve read traffic.<br/> > One **cannot** use the standby replica to serve read traffic.<br/>
> To serve read-only traffic, use a Multi-AZ DB cluster or a read replica instance instead. > To serve read-only traffic, use a Multi-AZ DB cluster or a read replica instance instead.
One can convert existing Single-AZ DB instances to Multi-AZ deployments just by modifying the DB instance.<br/>
This process involves minimal to no downtime, and requires planning around storage and performance impacts.
During a Single-AZ to Multi-AZ conversion, RDS:
1. Takes a snapshot of the primary DB instance's EBS volumes.
1. Creates new volumes for the standby replica from that snapshot.
1. Turns on synchronous block-level replication between the volumes of the primary and standby replicas.
It seems one can convert existing Multi-AZ DB instances to Single-AZ deployments just by modifying the DB instance.<br/>
This process seems to involve minimal to no downtime, and requires planning around storage and performance impacts.
During a Multi-AZ to Single-AZ conversion, RDS typically keeps the instance in the AZ where the primary was located.
Multi-AZ DB instance deployments have increased costs, and write and commit latency compared to Single-AZ deployments Multi-AZ DB instance deployments have increased costs, and write and commit latency compared to Single-AZ deployments
due to the synchronous data replication to the standby replica. due to the synchronous data replication to the standby replica.
@@ -571,6 +557,22 @@ the primary DB instance became unavailable. Large transactions or a lengthy reco
time.<br/> time.<br/>
When the failover is complete, it can take additional time for the RDS console to reflect the new AZ. When the failover is complete, it can take additional time for the RDS console to reflect the new AZ.
One can convert existing Single-AZ DB instances to Multi-AZ deployments just by modifying the DB instance.<br/>
This process involves minimal to no downtime, but requires planning around storage and performance impacts if done on
active instances.
During a Single-AZ to Multi-AZ conversion, RDS:
1. Takes a snapshot of the primary DB instance's EBS volumes.
1. Creates new volumes for the standby replica from that snapshot.
1. Turns on synchronous block-level replication between the volumes of the primary and standby replicas.
One can convert existing Multi-AZ DB instances to Single-AZ deployments just by modifying the DB instance.<br/>
This process involves minimal to no downtime, but requires planning around storage and performance impacts if done on
active instances.
During a Multi-AZ to Single-AZ conversion, RDS typically keeps the instance in the AZ where the primary was located.
## Operations ## Operations
### PostgreSQL: reduce allocated storage by migrating using transportable databases ### PostgreSQL: reduce allocated storage by migrating using transportable databases