[DPE-5827] Set all nodes to synchronous replicas

[dragomirp]

Set all replicas to sync

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 71.83%. Comparing base (4c4b810) to head (40a0948).
Report is 1 commits behind head on main.

Additional details and impacted files

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  Coverage   71.82%   71.83%           
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  Files          13       13           
  Lines        3219     3220    +1     
  Branches      477      476    -1     
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+ Hits         2312     2313    +1     
  Misses        791      791           
  Partials      116      116           

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[dragomirp]

REST calls should also use the new value.

[lucasgameiroborges]

Code LGTM, but why are we setting all nodes to be sync replicas? From the mentioned ticket it should come from a config value?

[dragomirp]

Code LGTM, but why are we setting all nodes to be sync replicas? From the mentioned ticket it should come from a config value?

What was discussed was to switch the default behaviour to all sync and add a config for controlling the amount of syncs. The config needs a spec. I'll comment on the ticket to clarify.

[marceloneppel]

Cool! Testing it, it's working fine in almost all scenarios.

The scenario where it's not working yet is the upgrade:

juju deploy postgresql --channel 14/stable -n 3

# Wait for the units to settle down, then:
curl UNIT-ZERO-IP:8008/cluster | jq # There is one leader, one sync-standby and one replica, as expected.

juju run postgresql/leader pre-upgrade-check

juju refresh --path ./*.charm postgresql

# Wait for the units to settle down, then:
curl UNIT-ZERO-IP:8008/cluster | jq # There is one leader, one sync-standby and one replica, but we should have one leader and two sync-standby only.

juju add-unit postgresql -n 1

# Wait for the units to settle down, then:
curl UNIT-ZERO-IP:8008/cluster | jq # There is one leader, and three sync-standby, as expected.

[taurus-forever]

LGTM, need some time to play it without rush.
Let's merge it after release the current PostgreSQL VM to stable.

[dragomirp]

The scenario where it's not working yet is the upgrade:

5082317 should fix the upgrade. Not adding an assertion to the integration tests because functionality will drift when the changes land on edge and stable.

[marceloneppel]

The scenario where it's not working yet is the upgrade:

5082317 should fix the upgrade. Not adding an assertion to the integration tests because functionality will drift when the changes land on edge and stable.

Thanks, Dragomir! LGTM!

[taurus-forever]

@dragomirp please do not forget to add config option synchronous_node_count as agreed in spec (with detailed description, the same as in spec).