When a node is drained, system jobs are left until last so that
operators can rely on things like log shippers running even as their
applications are getting drained off. Include CSI plugins in this set
so that Controller plugins deployed as services can be handled as
gracefully as Node plugins that are running as system jobs.
The previous output of the `nomad server members` command would output a
column named `Protocol` that displayed the Serf protocol being currently
used by servers.
This is not a configurable option, so it holds very little value to
operators. It is also easy to confuse it with the Raft Protocol version,
which is configurable and highly relevant to operators.
This commit replaces the previous `Protocol` column with the new `Raft
Version`. It also updates the `-detailed` flag to be called `-verbose`
so it matches other commands. The detailed output now also outputs the
same information as the standard output with the addition of the
previous `Protocol` column and `Tags`.
The `related` query param is used to indicate that the request should
return a list of related (next, previous, and blocked) evaluations.
Co-authored-by: Jasmine Dahilig <jasmine@hashicorp.com>
When a Nomad server becomes the Raft leader, it must perform several
actions defined in the establishLeadership function. If any of these
actions fail, Raft will think the node is the leader, but it will not
actually be able to act as a Nomad leader.
In this scenario, leadership must be revoked and transferred to another
server if possible, or the node should retry the establishLeadership
steps.
Clarify the behavior of `restart` inheritance with respect to Connect
sidecar tasks. Remove incorrect language about the scheduler being
involved in restart decisions. Try to make the `delay` mode
documentation more clear, and provide examples of delay vs fail.
The Docker DNS configuration options are not compatible with a
group-level network in `bridge` mode. Warn users about this in the
Docker task configuration docs.
The RPC for listing volume snapshots requires a plugin ID. Update the
`volume snapshot list` command to find the specific plugin from the
provided prefix.
The advertise.rpc config option is not intuitive. At first glance you'd
assume it works like advertise.http or advertise.serf, but it does not.
The current behavior is working as intended, but the documentation is
very hard to parse and doesn't draw a clear picture of what the setting
actually does.
Closes https://github.com/hashicorp/nomad/issues/11075
The dynamic plugin registry assumes that plugins are singletons, which
matches the behavior of other Nomad plugins. But because dynamic
plugins like CSI are implemented by allocations, we need to handle the
possibility of multiple allocations for a given plugin type + ID, as
well as behaviors around interleaved allocation starts and stops.
Update the data structure for the dynamic registry so that more recent
allocations take over as the instance manager singleton, but we still
preserve the previous running allocations so that restores work
without racing.
Multiple allocations can run on a client for the same plugin, even if
only during updates. Provide each plugin task a unique path for the
control socket so that the tasks don't interfere with each other.
Nomad inherited protocol version numbering configuration from Consul and
Serf, but unlike those projects Nomad has never used it. Nomad's
`protocol_version` has always been `1`.
While the code is effectively unused and therefore poses no runtime
risks to leave, I felt like removing it was best because:
1. Nomad's RPC subsystem has been able to evolve extensively without
needing to increment the version number.
2. Nomad's HTTP API has evolved extensively without increment
`API{Major,Minor}Version`. If we want to version the HTTP API in the
future, I doubt this is the mechanism we would choose.
3. The presence of the `server.protocol_version` configuration
parameter is confusing since `server.raft_protocol` *is* an important
parameter for operators to consider. Even more confusing is that
there is a distinct Serf protocol version which is included in `nomad
server members` output under the heading `Protocol`. `raft_protocol`
is the *only* protocol version relevant to Nomad developers and
operators. The other protocol versions are either deadcode or have
never changed (Serf).
4. If we were to need to version the RPC, HTTP API, or Serf protocols, I
don't think these configuration parameters and variables are the best
choice. If we come to that point we should choose a versioning scheme
based on the use case and modern best practices -- not this 6+ year
old dead code.
These API endpoints now return results in chronological order. They
can return results in reverse chronological order by setting the
query parameter ascending=true.
- Eval.List
- Deployment.List
