* Avoid retries when syncing replication slots.
Do not retry postgres queries that fetch, create and drop slots at the end of
the HA cycle. The complete run_cycle routine executes with the async_executor
lock. This lock is also used with scheduling operations like reinit or restart
in different threads. Looks like CPython threading class has fairness issues
when multiple threads try to acquire the same lock and one of them executes
long-running actions while holding it: the others have little chances of
acquiring the lock in order. To get around this issue, the long action (i.e.
retrying the query) is removed.
Investigation by Ants Aasma and Alexander Kukushkin.
When running this script using Python3, the output is bytestring instead of string.
We explicitly decode it to ensure checks further down are ok.
The trigger for this patch is:
ERROR: unable to get some of WALE backup parameters: 'expanded_size_bytes'
This error is send by etcd when Patroni is doing "watch" on leader key
which is never updated after creation and etcd cluster receives a lot of
updates, what cleans history of events.
Instead of doing watch on modifiedIndex + 1 we will do watch on X-Etcd-Index,
which is probably still available...
- fix the false claim that Patroni in a paused mode may promote a master.
- merge all allowed API actions together.
- describe the payload of the API pause request as JSON.
PostgreSQL replication slot names only allow names consisting of [a-z0-9_].
Invalid characters cause replication slot creation and standby startup to fail.
This change substitutes the invalid characters with underscores or unicode
codepoints. In case multiple member names map to identical replication slots
master log will contain a corresponding error message.
Motivated by wanting to use hostnames as member names. Hostnames often
contain periods and dashes.
Master tried to delete all slots that did not correspond to the
replica registered in Patroni. That produced an error for the slots
that were active, potentially preventing drop and creation of other
slots.
Reported by Murat Kabilov.
The v1.0 has been released more than one month ago and the new version
is coming. It doesn't make a lot of sense to keep configuration files in
the old format anymore.
In addition to that I've also commented out all the lines enabling and
configuring "archiving" to avoid incidents like here:
https://github.com/zalando/patroni/issues/264
