marisastrong
commented
3 years ago DB instances using Multi-AZ deployments can have increased write and commit latency compared to a Single-AZ deployment, due to the synchronous data replication that occurs. You might have a change in latency if your deployment fails over to the standby replica, although AWS is engineered with low-latency network connectivity between Availability Zones. For production workloads, we recommend that you use Provisioned IOPS and DB instance classes that are optimized for Provisioned IOPS for fast, consistent performance. For more information about DB instance classes, see DB instance classes.
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Concepts.MultiAZ.html
Are we using Provisioned IOPS and is the t3 instance class optimized for this?
Determine how service will be affected during maintenance. Full 30 minute downtime may be needed.
EZID Notification Messages for Stage RDS Upgrades
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 20:39:31.221
Message : DB instance shutdown
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0004
Nagios Alert Notification Type: PROBLEM
Service: ezid-stg_tg_UnhealthyHosts_5x12 Host: ezid-stg Address: ezid-stg.cdlib.org State: CRITICAL
Date/Time: Tue Jan 19 12:42:08 PST 2021
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 20:43:13.803
Message : DB instance restarted
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0006
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 20:46:54.675
Message : Database instance patched
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0047
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 20:49:07.209
Message : Applying modification to database instance class
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0012
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 20:54:45.931
Message : DB instance shutdown
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0004
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 20:55:31.639
Message : Multi-AZ instance failover started.
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0013
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 20:55:36.809
Message : DB instance restarted
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0006
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 20:56:01.582
Message : Multi-AZ instance failover completed
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0049
Nagios Alert
Notification Type: RECOVERY
Service: ezid-stg_tg_UnhealthyHosts_5x12 Host: ezid-stg Address: ezid-stg.cdlib.org State: OK
Date/Time: Tue Jan 19 13:02:08 PST 2021
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 21:03:04.847
Message : Finished applying modification to DB instance class
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0014
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 21:04:18.903
Message : Monitoring Interval changed to 0
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0078
SourceId: rds-ias-ezid-search2-stg
Notification time : 2021-01-19 21:05:21.297
Message : Finished updating DB parameter group
Event ID : http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0092