* scheduler: allow updates after alloc reconnects
When an allocation reconnects to a cluster the scheduler needs to run
special logic to handle the reconnection, check if a replacement was
create and stop one of them.
If the allocation kept running while the node was disconnected, it will
be reconnected with `ClientStatus: running` and the node will have
`Status: ready`. This combination is the same as the normal steady state
of allocation, where everything is running as expected.
In order to differentiate between the two states (an allocation that is
reconnecting and one that is just running) the scheduler needs an extra
piece of state.
The current implementation uses the presence of a
`TaskClientReconnected` task event to detect when the allocation has
reconnected and thus must go through the reconnection process. But this
event remains even after the allocation is reconnected, causing all
future evals to consider the allocation as still reconnecting.
This commit changes the reconnect logic to use an `AllocState` to
register when the allocation was reconnected. This provides the
following benefits:
- Only a limited number of task states are kept, and they are used for
many other events. It's possible that, upon reconnecting, several
actions are triggered that could cause the `TaskClientReconnected`
event to be dropped.
- Task events are set by clients and so their timestamps are subject
to time skew from servers. This prevents using time to determine if
an allocation reconnected after a disconnect event.
- Disconnect events are already stored as `AllocState` and so storing
reconnects there as well makes it the only source of information
required.
With the new logic, the reconnection logic is only triggered if the
last `AllocState` is a disconnect event, meaning that the allocation has
not been reconnected yet. After the reconnection is handled, the new
`ClientStatus` is store in `AllocState` allowing future evals to skip
the reconnection logic.
* scheduler: prevent spurious placement on reconnect
When a client reconnects it makes two independent RPC calls:
- `Node.UpdateStatus` to heartbeat and set its status as `ready`.
- `Node.UpdateAlloc` to update the status of its allocations.
These two calls can happen in any order, and in case the allocations are
updated before a heartbeat it causes the state to be the same as a node
being disconnected: the node status will still be `disconnected` while
the allocation `ClientStatus` is set to `running`.
The current implementation did not handle this order of events properly,
and the scheduler would create an unnecessary placement since it
considered the allocation was being disconnected. This extra allocation
would then be quickly stopped by the heartbeat eval.
This commit adds a new code path to handle this order of events. If the
node is `disconnected` and the allocation `ClientStatus` is `running`
the scheduler will check if the allocation is actually reconnecting
using its `AllocState` events.
* rpc: only allow alloc updates from `ready` nodes
Clients interact with servers using three main RPC methods:
- `Node.GetAllocs` reads allocation data from the server and writes it
to the client.
- `Node.UpdateAlloc` reads allocation from from the client and writes
them to the server.
- `Node.UpdateStatus` writes the client status to the server and is
used as the heartbeat mechanism.
These three methods are called periodically by the clients and are done
so independently from each other, meaning that there can't be any
assumptions in their ordering.
This can generate scenarios that are hard to reason about and to code
for. For example, when a client misses too many heartbeats it will be
considered `down` or `disconnected` and the allocations it was running
are set to `lost` or `unknown`.
When connectivity is restored the to rest of the cluster, the natural
mental model is to think that the client will heartbeat first and then
update its allocations status into the servers.
But since there's no inherit order in these calls the reverse is just as
possible: the client updates the alloc status and then heartbeats. This
results in a state where allocs are, for example, `running` while the
client is still `disconnected`.
This commit adds a new verification to the `Node.UpdateAlloc` method to
reject updates from nodes that are not `ready`, forcing clients to
heartbeat first. Since this check is done server-side there is no need
to coordinate operations client-side: they can continue sending these
requests independently and alloc update will succeed after the heartbeat
is done.
* chagelog: add entry for #15068
* code review
* client: skip terminal allocations on reconnect
When the client reconnects with the server it synchronizes the state of
its allocations by sending data using the `Node.UpdateAlloc` RPC and
fetching data using the `Node.GetClientAllocs` RPC.
If the data fetch happens before the data write, `unknown` allocations
will still be in this state and would trigger the
`allocRunner.Reconnect` flow.
But when the server `DesiredStatus` for the allocation is `stop` the
client should not reconnect the allocation.
* apply more code review changes
* scheduler: persist changes to reconnected allocs
Reconnected allocs have a new AllocState entry that must be persisted by
the plan applier.
* rpc: read node ID from allocs in UpdateAlloc
The AllocUpdateRequest struct is used in three disjoint use cases:
1. Stripped allocs from clients Node.UpdateAlloc RPC using the Allocs,
and WriteRequest fields
2. Raft log message using the Allocs, Evals, and WriteRequest fields
3. Plan updates using the AllocsStopped, AllocsUpdated, and Job fields
Adding a new field that would only be used in one these cases (1) made
things more confusing and error prone. While in theory an
AllocUpdateRequest could send allocations from different nodes, in
practice this never actually happens since only clients call this method
with their own allocations.
* scheduler: remove logic to handle exceptional case
This condition could only be hit if, somehow, the allocation status was
set to "running" while the client was "unknown". This was addressed by
enforcing an order in "Node.UpdateStatus" and "Node.UpdateAlloc" RPC
calls, so this scenario is not expected to happen.
Adding unnecessary code to the scheduler makes it harder to read and
reason about it.
* more code review
* remove another unused test
Whenever a node joins the cluster, either for the first time or after
being `down`, we emit a evaluation for every system job to ensure all
applicable system jobs are running on the node.
This patch adds an optimization to skip creating evaluations for system
jobs not in the current node's DC. While the scheduler performs the same
feasability check, skipping the creation of the evaluation altogether
saves disk, network, and memory.
Move some common Vault API data struct decoding out of the Vault client
so it can be reused in other situations.
Make Vault job validation its own function so it's easier to expand it.
Rename the `Job.VaultPolicies` method to just `Job.Vault` since it
returns the full Vault block, not just their policies.
Set `ChangeMode` on `Vault.Canonicalize`.
Add some missing tests.
Allows specifying an entity alias that will be used by Nomad when
deriving the task Vault token.
An entity alias assigns an indentity to a token, allowing better control
and management of Vault clients since all tokens with the same indentity
alias will now be considered the same client. This helps track Nomad
activity in Vault's audit logs and better control over Vault billing.
Add support for a new Nomad server configuration to define a default
entity alias to be used when deriving Vault tokens. This default value
will be used if the task doesn't have an entity alias defined.
When a node fails its heart beating a number of actions are taken
to ensure state is cleaned. Service registrations a loosely tied
to nodes, therefore we should remove these from state when a node
is considered terminally down.
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.
PR #11956 implemented a new mTLS RPC check to validate the role of the
certificate used in the request, but further testing revealed two flaws:
1. client-only endpoints did not accept server certificates so the
request would fail when forwarded from one server to another.
2. the certificate was being checked after the request was forwarded,
so the check would happen over the server certificate, not the
actual source.
This commit checks for the desired mTLS level, where the client level
accepts both, a server or a client certificate. It also validates the
cercertificate before the request is forwarded.
When a node becomes ready, create an eval for all system jobs across
namespaces.
The previous code uses `job.ID` to deduplicate evals, but that ignores
the job namespace. Thus if there are multiple jobs in different
namespaces sharing the same ID/Name, only one will be considered for
running in the new node. Thus, Nomad may skip running some system jobs
in that node.
Fix a bug where system jobs may fail to be placed on a node that
initially was not eligible for system job placement.
This changes causes the reschedule to re-evaluate the node if any
attribute used in feasibility checks changes.
Fixes https://github.com/hashicorp/nomad/issues/8448
This PR adds the common OSS changes for adding support for Consul Namespaces,
which is going to be a Nomad Enterprise feature. There is no new functionality
provided by this changeset and hopefully no new bugs.
node drain: use msgtype on txn so that events are emitted
wip: encoding extension to add Node.Drain field back to API responses
new approach for hiding Node.SecretID in the API, using `json` tag
documented this approach in the contributing guide
refactored the JSON handlers with extensions
modified event stream encoding to use the go-msgpack encoders with the extensions
Fixes#9017
The ?resources=true query parameter includes resources in the object
stub listings. Specifically:
- For `/v1/nodes?resources=true` both the `NodeResources` and
`ReservedResources` field are included.
- For `/v1/allocations?resources=true` the `AllocatedResources` field is
included.
The ?task_states=false query parameter removes TaskStates from
/v1/allocations responses. (By default TaskStates are included.)
Add a Postrun hook to send the `CSIVolume.Unpublish` RPC to the server. This
may forward client RPCs to the node plugins or to the controller plugins,
depending on whether other allocations on this node have claims on this
volume.
By making clients responsible for running the `CSIVolume.Unpublish` RPC (and
making the RPC available to a `nomad volume detach` command), the
volumewatcher becomes only used by the core GC job and we no longer need
async volume GC from job deregister and node update.
This PR adds the capability of running Connect Native Tasks on Nomad,
particularly when TLS and ACLs are enabled on Consul.
The `connect` stanza now includes a `native` parameter, which can be
set to the name of task that backs the Connect Native Consul service.
There is a new Client configuration parameter for the `consul` stanza
called `share_ssl`. Like `allow_unauthenticated` the default value is
true, but recommended to be disabled in production environments. When
enabled, the Nomad Client's Consul TLS information is shared with
Connect Native tasks through the normal Consul environment variables.
This does NOT include auth or token information.
If Consul ACLs are enabled, Service Identity Tokens are automatically
and injected into the Connect Native task through the CONSUL_HTTP_TOKEN
environment variable.
Any of the automatically set environment variables can be overridden by
the Connect Native task using the `env` stanza.
Fixes#6083
* changes necessary to support oss licesning shims
revert nomad fmt changes
update test to work with enterprise changes
update tests to work with new ent enforcements
make check
update cas test to use scheduler algorithm
back out preemption changes
add comments
* remove unused method
Following the new volumewatcher in #7794 and performance improvements
to it that landed afterwards, there's no particular reason we should
be threading claim releases through the GC eval rather than writing an
empty `CSIVolumeClaimRequest` with the mode set to
`CSIVolumeClaimRelease`, just as the GC evaluation would do.
Also, by batching up these raft messages, we can reduce the amount of
raft writes by 1 and cross-server RPCs by 1 per volume we release
claims on.
Fixes#8000
When requesting a Service Identity token from Consul, use the TaskKind
of the Task to get at the service name associated with the task. In
the past using the TaskName worked because it was generated as a sidecar
task with a name that included the service. In the Native context, we
need to get at the service name in a more correct way, i.e. using the
TaskKind which is defined to include the service name.
This changeset adds a subsystem to run on the leader, similar to the
deployment watcher or node drainer. The `Watcher` performs a blocking
query on updates to the `CSIVolumes` table and triggers reaping of
volume claims.
This will avoid tying up scheduling workers by immediately sending
volume claim workloads into their own loop, rather than blocking the
scheduling workers in the core GC job doing things like talking to CSI
controllers
The volume watcher is enabled on leader step-up and disabled on leader
step-down.
The volume claim GC mechanism now makes an empty claim RPC for the
volume to trigger an index bump. That in turn unblocks the blocking
query in the volume watcher so it can assess which claims can be
released for a volume.
The `Job.Deregister` call will block on the client CSI controller RPCs
while the alloc still exists on the Nomad client node. So we need to
make the volume claim reaping async from the `Job.Deregister`. This
allows `nomad job stop` to return immediately. In order to make this
work, this changeset changes the volume GC so that the GC jobs are on a
by-volume basis rather than a by-job basis; we won't have to query
the (possibly deleted) job at the time of volume GC. We smuggle the
volume ID and whether it's a purge into the GC eval ID the same way we
smuggled the job ID previously.
When an alloc is marked terminal (and after node unstage/unpublish
have been called), the client syncs the terminal alloc state with the
server via `Node.UpdateAlloc RPC`.
For each job that has a terminal alloc, the `Node.UpdateAlloc` RPC
handler at the server will emit an eval for a new core job to garbage
collect CSI volume claims. When this eval is handled on the core
scheduler, it will call a `volumeReap` method to release the claims
for all terminal allocs on the job.
The volume reap will issue a `ControllerUnpublishVolume` RPC for any
node that has no alloc claiming the volume. Once this returns (or
is skipped), the volume reap will send a new `CSIVolume.Claim` RPC
that releases the volume claim for that allocation in the state store,
making it available for scheduling again.
This same `volumeReap` method will be called from the core job GC,
which gives us a second chance to reclaim volumes during GC if there
were controller RPC failures.
Currently, the client has to ship an entire allocation to the server as
part of performing a VolumeClaim, this has a few problems:
Firstly, it means the client is sending significantly more data than is
required (an allocation contains the entire contents of a Nomad job,
alongside other irrelevant state) which has a non-zero (de)serialization
cost.
Secondly, because the allocation was never re-fetched from the state
store, it means that we were potentially open to issues caused by stale
state on a misbehaving or malicious client.
The change removes both of those issues at the cost of a couple of more
state store lookups, but they should be relatively cheap.
We also now provide the CSIVolume in the response for a claim, so the
client can perform a Claim without first going ahead and fetching all of
the volumes.
When an alloc is marked terminal, and after node unstage/unpublish
have been called, the client will sync the terminal alloc state with
the server via `Node.UpdateAlloc` RPC.
This changeset implements releasing the volume claim for each volume
associated with the terminal alloc. It doesn't yet implement the RPC
call we need to make to the `ControllerUnpublishVolume` CSI RPC.
This fixes a bug where a forwarded node update request may be assumed
to be the actual direct client connection if the server just lost
leadership.
When a nomad non-leader server receives a Node.UpdateStatus request, it
forwards the RPC request to the leader, and holds on the request
Yamux connection in a cache to allow for server<->client forwarding.
When the leader handles the request, it must differentiate between a
forwarded connection vs the actual connection. This is done in
https://github.com/hashicorp/nomad/blob/v0.10.4/nomad/node_endpoint.go#L412
Now, consider if the non-leader server forwards to the connection to a
recently deposed nomad leader, which in turn forwards the RPC request to
the new leader.
Without this change, the deposed leader will mistake the forwarded
connection for the actual client connection and cache it mapped to the
client ID. If the server attempts to connect to that client, it will
attempt to start a connection/session to the other server instead and
the call will hang forever.
This change ensures that we only add node connection mapping if the
request is not a forwarded request, regardless of circumstances.
Nomad jobs may be configured with a TaskGroup which contains a Service
definition that is Consul Connect enabled. These service definitions end
up establishing a Consul Connect Proxy Task (e.g. envoy, by default). In
the case where Consul ACLs are enabled, a Service Identity token is required
for these tasks to run & connect, etc. This changeset enables the Nomad Server
to recieve RPC requests for the derivation of SI tokens on behalf of instances
of Consul Connect using Tasks. Those tokens are then relayed back to the
requesting Client, which then injects the tokens in the secrets directory of
the Task.
Luiz Aoqui