Rename the follow_the_leader to just follow, since the node to
be followed is not necessary a leader anymore. Extend the code
that manages replication slots to the non-master nodes if they
are mentioned in at least one replicatefrom tag.
Add the 3rd configuration in order to be able to run cascading
replicas.
Call normal follow the leader method from HA even during recovery.
This provides a single place that changes recovery.conf, making
it easier to plug in a cascading replica in the future.
Remove an obsolete demote function from PostreSQL module, modified
the tests.
PostgreSQL does not run a checkpoint during promition.
Since pg_rewind relies on the last checkpoint to get the timeline,
there is a short race condition right after the promotion, when
it can get the timeline wrong and fail. We work around this by
calling the checkpoint manually.
Make sure our test configuration does both archive and recovery.
- command is deleted from method_config without checking whether
it was there in the first place.
- write_recovery_conf is called before the recovery file is restored
from the backup location.
Previously, patroni would die after receiving an exception
other than RetryFailedError, etcd.EtcdException from etcd.
We have observed an AttributeError raised by etcd on some
occasions. With this change, we demote ourselves, but not
terminate on such exceptions.
By default, haproxy sens an OPTION request, which we didn't
handle until now. In addition, all haproxy requests that doesn't
examine the request body close the connection as soon as the status
code is obtained. Such behavior breaks BaseHTTPRequestHandler,
namely handle_one_request, which doesn't check for connection reset
by peer and throw this error on a higher level, but since we don't
call this function directly, there is no place in the code to catch
it, therefore, we have to patch this function in the base class.
In addition, patch the StreamRequestHandler finish() function in
order to handle the connection reset error.
Re-read the cluster from DCS right after the failover to supply
the correct new values to the API thread. Fix a typo.
Instead of checking that nofailover node should not
be marked as healthiest in one of the _failover
functions, do make it unhealthy in the is_healthiest_node.
The initialize key was checked against the value
of the node name before removal, but it was changed
recently to contain either an empty string, or cluster
sysid. To fix this, the check for the previous value
was simply removed: we can guarantee that the code path
that removes the key is the one that created it.
Tags are labels assigned to individual members in order
to alter its default behavior, i.e. exclude from the
leader election or indicate a possibility to create base
backups from the member.
This commit only adds support for setting tags in the
configuration file, exposes the tags to DCS /member subkey
and returns the tags in a response of the API request. At
the moment the tag names are not validated, nor they are
interpreted in any way.
Support for setting tags via the API is also in the scope
of further work.
One can use pgpass configuration parameter in the postgres
subsection of Patroni. By default pgpass is written in ~/.
Mock actual writes to pgpass in the tests.
I accidentially removed the call when moving the backup functions
to the external script. It is intended to save the configuration,
so that at the restore phase one can just copy backup files.
Its primary intention was to save configuration files in the WAL-E
case (WAL-E just omits everything with .conf), but it is also
useful in the pg_basebackup case, which omits all symlinks, leaving
the cluster with .conf files symlinked in the broken state.
After the PostgreSQL crash (i.e. with kill -9), the backend
patroni connects to may still exist. In this case, patroni
will get stale postgres role from this backend, preventing
a restarted node with a leader lock from being promoted.
Easily reproducible and also observed in a staging environment
after the postgres crash due to out of disk space.
- check the link before checking the file when deciding to remove it,
as isfile follows symlinks and, therefore, may return True on them.
- Remove append mode from write_pgpass, as it is always written anew
before it is used.
- make pg_controldata return an empty hash in case of an error, and
check for the empty value return by this function before using it.
some other minior fixed and test updates.
If patroni detects the former master was killed, it runs
it first in a single-user mode and then shuts down normally,
to make sure pg_rewind will see a normal shut down status
in pg_controldata.
Add a flag need_rewind, since the point where it is detected
that rewind might be necessary is moved out the code that
runs rewind.
Prevent treating the incompletely-initialized PostgreSQL cluster
as a valid on restart by forcefully moving the data directory.
I don't want to remove it altogether, since a DBA might decide
to analyze the failed PG cluster in order to resolve the init
issue.
If initializer node suddenly dies before the initialization is complete,
other nodes should try to take over.
Fix some unittests for etcd and zookeeper and add couple of new ones.
Oleksii Kliukin