How to Avoid Downtime in HA

Nikolay and Michael discuss HA (high availability) — what it means, tools and techniques for maximising it, while going through some of the more common causes of downtime. 
 
Here are some links to some things they mentioned:

• https://en.wikipedia.org/wiki/High_availability
• https://postgres.fm/episodes/upgrades   
• https://github.com/shayonj/pg_easy_replicate/ 
• pg_easy_replicate discussion on Hacker News https://news.ycombinator.com/item?id=36405761 
• https://postgres.fm/episodes/connection-poolers 
• https://www.postgresql.org/docs/current/libpq.html  
• Support load balancing in libpq (new feature in Postgres 16)
  https://commitfest.postgresql.org/42/3679/ 
• target_session_attrs options for high availability and scaling (2021; a post by Laurenz Albe) https://www.cybertec-postgresql.com/en/new-target_session_attrs-settings-for-high-availability-and-scaling-in-postgresql-v14/
• Postgres 10 highlight - read-write and read-only mode of libpq (2016, a post by Michael Paquier) https://paquier.xyz/postgresql-2/postgres-10-libpq-read-write/ 
• Postgres 10 highlight - Quorum set of synchronous standbys (2017, a post by Michael Paquier) https://paquier.xyz/postgresql-2/postgres-10-quorum-sync/
• https://github.com/zalando/patroni 
• https://postgres.fm/episodes/replication 
• https://blog.rustprooflabs.com/2021/06/postgres-bigint-by-default 
• Zero-downtime Postgres schema migrations need this: lock_timeout and retries (2021) https://postgres.ai/blog/20210923-zero-downtime-postgres-schema-migrations-lock-timeout-and-retries 
• A fix in Patroni to mitigate a very long shutdown attempt when archive_command has a lot of WALs to archive https://github.com/zalando/patroni/pull/2067 

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What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!

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Postgres FM is brought to you by:

• Nikolay Samokhvalov, founder of Postgres.ai
• Michael Christofides, founder of pgMustard

With special thanks to:

• Jessie Draws for the amazing artwork