This is an original planning guide. It is not a vendor manual, an official standard, or legal advice. Example addresses use documentation ranges. Review every command before you paste it.
What this hour is for
The generator writes a scope, an etcd address, and a REST listen of 0.0.0.0:8008. Replace that listen with an address you administer. pg_rewind is in the draft. Turn it on only when you understand the timeline rules. The note says to review the DCS address.
The neighbouring script reads replication state. It does not fail the cluster over. Do not apply the file during the reading. Do not fail over.
192.0.2.10, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. A sample password is replaced. It is not a password you keep.
The change you can finish
Apply nothing while you are writing the note. When the lab window opens, it is one change on the database named in the ticket. Read the draft, then the database, then decide.
Rollback is the backup, the file, or the snapshot you saved first. You do not invent a rollback after the only copy is gone.
- Replace 0.0.0.0:8008.
- Replace the etcd address.
- Read the pg_rewind line.
- Do not apply the file.
- Stop.
Mistakes that outlive the statement
PostgreSQL HA with Patroni goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- 0.0.0.0 left in the file.
- The file applied during the reading.
- A failover during the reading.
- pg_rewind enabled with no timeline note.
Decisions to write down
One decision for PostgreSQL HA with Patroni: The listen address is yours. The DCS address is yours. Nothing was applied. And nothing failed over.
Checks before you call it done
Confirm this before you call the change done: The listen address was replaced. The DCS address is yours. pg_rewind is off or explained. Nothing was applied. And the cluster is yours. If one of those fails, stop.
# Replace listen 0.0.0.0:8008.
# Review the DCS address.
# Do not apply the file during the reading.
# Do not fail over.Before you leave the database
PostgreSQL HA with Patroni ends when the database in the prompt is the database in the ticket. If it is not, you are on the wrong database. Stop.
The draft stays a draft until a person has read the names in it. A generator does not log into the database. You delete a line that names a host, a database, or an account you did not write down.
192.0.2.10, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you leave on a database because a draft included them.
prompt-for-this is a reminder that a secret is missing. It is not a password, a key, or a token you save in the ticket or in git. A sample password in a draft is replaced. It is not a password you keep.
One change is the window. If two things move and the result is wrong, you will not know which one did it.
If the same step fails twice, stop for the day. Restore the copy you took first.
A second person reads the database name and the change aloud. If they cannot find them in the ticket, the note is not done.
This page is a planning guide. It is not a vendor manual, not an official standard, and not permission to touch a database you do not administer. You do not disable authentication, a firewall, or TLS to make a check pass.
Tools for this guide
These tools run in the browser on this site. They do not log into your machines.
Related pillar guides
More in this cluster
The pillar for this page, and the next published pages filed with it.