Steps which I follow in this video.
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==Perform the Upgrade
1). Go to RDS Console
2). Select DB instance
3). Click Modify
4). Under DB engine version, choose 16.9
==Choose:
Apply immediately OR Apply during maintenance window
Click Continue → Modify DB Instance
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Extra tip to monitor the steps of upgrade.
1). Click on the DB name.
2). Select Logs/Events.
3). Scroll down to Events and note down the steps involved in minor upgrade.
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High Level steps for Interview preparation
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Understand What a Minor Upgrade Does.
Check Available Target Version.
Review Compatibility & Release Notes.
Take a Backup (Critical and crucial for realtime)
--------------Once upgrade done then-----------------------
1). Test Critical Functions
2). Run application queries
Validate:
1). Connections
2). Performance
3). Extensions working
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High level Tips-:
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1).Multi-Availibility Zone setup will reduces downtime impact.
2).Read replica upgrade first to ensure there is no issues (best practice).
3).Always test in staging before production
4).Monitor logs after upgrade for hidden issues
Links for Details idea-: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_UpgradeDBInstance.PostgreSQL.Minor.html
