Current etcd implementation does not yet support timeout option when
`wait=true`: https://github.com/coreos/etcd/issues/2468
Originaly I've implemented `watch` method for `Etcd` class in a
following manner: if the leader key was updated just because master
needs to update ttl and watch timeout is not yet expired, I was
recalculating timeout and starting `watch` call once again.
Usually after "restart" we were getting urllib3.exceptions.TimeoutError.
The only possible way to recover after such exception - close socket and
establish a new connection. With pure http it's relatively cheap, but
with https and some kind of authorization on etcd side it would became
rather expensive and should be avoided.
Previous implementation was always setting Cluster.initialize to True.
Also it was throwing ZooKeeperError when there were no members in a
cluster.
Plus BUGFIX of a bug introduced with
https://github.com/zalando/patroni/pull/34 in a `load_members` method.
- data = self.get_node(self.member_path)
+ data = self.get_node(self.members_path + member)
It was always fetching the same node for all cluster members.
Fortunately Etcd doesn't have such problem because we are fetching the
whole cluster directory with one recursive API call.
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.
Also define following properties:
* initialize_path
* members_path
* member_path
* leader_path
* leader_optime_path
And replace any occurrences of these strings or client_path calls in a
etcd and zookeeper implementations with given constants and properties.
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.
Cleanup the initialize flag if the initializing node fails
to bootstrap its PostgreSQL database.
Rename dcs.race to initialize, since we only call it for the
initialize flag. Factored out PostgreSQL bootstrapping code
into a separate function.
As the Dockerfile is there mainly to support developers, we want to build the Dockerfile using the current working
directory instead of a previously released version.
Alexander Kukushkin