It allows us to use raft::EntryType directly without obscure i32 tricks.

Georgy Moshkin authored 2 years ago and Georgy Moshkin committed 2 years ago

deactivation means that instance
- is demoted to learner (if it wasn't one already)
- is marked "inactive" so that it's ignored when determining
    the number of voters required for the cluster

Georgy Moshkin authored 2 years ago and Georgy Moshkin committed 2 years ago

Topology::diff, Topology::to_replace, etc. only store ids, so that
peer info is consistent

Yaroslav Dynnikov authored 2 years ago and Yaroslav Dynnikov committed 2 years ago

Bootstrapping the replication was implemented in 2dac77c5. But it was
configured on the new instance only. The old instance (that joined
earlier) couldn't update `box.cfg({replication})` until now.

Close https://git.picodata.io/picodata/picodata/picodata/-/issues/52

Just supply it with a default value "demo". No new tests are necessary,
we already have `test/int/test_joining.py::test_cluster_id_mismatch`.

Close https://git.picodata.io/picodata/picodata/picodata/-/issues/96

If proc_discover is invoked after raft node was initialized but before
raft leader was elected, it would return an error before this commit.
Because of that it was impossible to restart the whole cluster at once.

This commit change proc_discover such that in case leader_id is not
ready, the normal discovery algorithm takes place.

Closes #93

* Make `--cluster-id` CLI mandatory.
* Handle cluster_id mismatch in raft_join.
  When an instance attempts to join the cluster and the instances's
  `--instance-id` parameter mismatches the cluster_id of the cluster
  an error is raised inside the raft_join handler.

Previously the discovery algorithm would try to reach each known peer
sequentially requiring each consequent request to succeed until the next
one can be attempted. This would not work in some cases (see test in
previous commit).

So the new algorithm instead makes a single attempt to reach each peer
within a round, and if some failed they're retried in the next round of
requests. This allows overall discovery to succeed in cases when some
of the initial peers never respond.

Closes #54

The `peer_address` parameter is an inbound address used for
communication with the peer. It shouldn't be confused with the listen
address. The persisted `peer_address` may become obsolete due to
circumstances beyond picodata control (e.g. DNS or IP changes). Thus
there's no point in its prior validation, including the uniqueness
check.

There's also no such task as getting peer by peer_address.

To sum up, an index over `peer_address` is useless. It only creates
problems and causes panics.

Close https://git.picodata.io/picodata/picodata/picodata/-/issues/88