This fixes a bug where jobs may get "stuck" unprocessed that
dispropotionately affect periodic jobs around leadership transitions.
When registering a job, the job registration and the eval to process it
get applied to raft as two separate transactions; if the job
registration succeeds but eval application fails, the job may remain
unprocessed. Operators may detect such failure, when submitting a job
update and get a 500 error code, and they could retry; periodic jobs
failures are more likely to go unnoticed, and no further periodic
invocations will be processed until an operator force evaluation.
This fixes the issue by ensuring that the job registration and eval
application get persisted and processed atomically in the same raft log
entry.
Also, applies the same change to ensure atomicity in job deregistration.
Backward Compatibility
We must maintain compatibility in two scenarios: mixed clusters where a
leader can handle atomic updates but followers cannot, and a recent
cluster processes old log entries from legacy or mixed cluster mode.
To handle this constraints: ensure that the leader continue to emit the
Evaluation log entry until all servers have upgraded; also, when
processing raft logs, the servers honor evaluations found in both spots,
the Eval in job (de-)registration and the eval update entries.
When an updated server sees mix-mode behavior where an eval is inserted
into the raft log twice, it ignores the second instance.
I made one compromise in consistency in the mixed-mode scenario: servers
may disagree on the eval.CreateIndex value: the leader and updated
servers will report the job registration index while old servers will
report the index of the eval update log entry. This discripency doesn't
seem to be material - it's the eval.JobModifyIndex that matters.
The `nomad volume deregister` command currently returns an error if the volume
has any claims, but in cases where the claims can't be dropped because of
plugin errors, providing a `-force` flag gives the operator an escape hatch.
If the volume has no allocations or if they are all terminal, this flag
deletes the volume from the state store, immediately and implicitly dropping
all claims without further CSI RPCs. Note that this will not also
unmount/detach the volume, which we'll make the responsibility of a separate
`nomad volume detach` command.
Handle case where a snapshot is made before cluster metadata is created.
This fixes a bug where a server may have empty cluster metadata if it
created and installed a Raft snapshot before a new cluster metadata ID is
generated.
This case is very unlikely to arise. Most likely reason is when
upgrading from an old version slowly where servers may use snapshots
before all servers upgrade. This happened for a user with a log line
like:
```
2020-05-21T15:21:56.996Z [ERROR] nomad.fsm: ClusterSetMetadata failed: error=""set cluster metadata failed: refusing to set new cluster id, previous: , new: <<redacted>
```
Ensure that `""` Scheduler Algorithm gets explicitly set to binpack on
upgrades or on API handling when user misses the value.
The scheduler already treats `""` value as binpack. This PR merely
ensures that the operator API returns the effective value.
This changeset implements a periodic garbage collection of unused CSI
plugins. Plugins are self-cleaning when the last allocation for a
plugin is stopped, but this feature will cover any missing edge cases
and ensure that upgrades from 0.11.0 and 0.11.1 get any stray plugins
cleaned up.
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.
Adds a `CSIVolumeClaim` type to be tracked as current and past claims
on a volume. Allows for a client RPC failure during node or controller
detachment without having to keep the allocation around after the
first garbage collection eval.
This changeset lays groundwork for moving the actual detachment RPCs
into a volume watching loop outside the GC eval.
The `csi_plugins` and `csi_volumes` tables were missing support for
snapshot persist and restore. This means restoring a snapshot would
result in missing information for CSI.
* added method to retrieve all scaling policies for use in snapshotting, plus test
* better testing for ScalingPoliciesByNamespace
* added scaling policy snapshot persist and restore (and test of restore)
manually tested snapshot restore.
resolves#7539
* nomad/state/schema: use the namespace compound index
* scheduler/scheduler: CSIVolumeByID interface signature namespace
* scheduler/stack: SetJob on CSIVolumeChecker to capture namespace
* scheduler/feasible: pass the captured namespace to CSIVolumeByID
* nomad/state/state_store: use namespace in csi_volume index
* nomad/fsm: pass namespace to CSIVolumeDeregister & Claim
* nomad/core_sched: pass the namespace in volumeClaimReap
* nomad/node_endpoint_test: namespaces in Claim testing
* nomad/csi_endpoint: pass RequestNamespace to state.*
* nomad/csi_endpoint_test: appropriately failed test
* command/alloc_status_test: appropriately failed test
* node_endpoint_test: avoid notTheNamespace for the job
* scheduler/feasible_test: call SetJob to capture the namespace
* nomad/csi_endpoint: ACL check the req namespace, query by namespace
* nomad/state/state_store: remove deregister namespace check
* nomad/state/state_store: remove unused CSIVolumes
* scheduler/feasible: CSIVolumeChecker SetJob -> SetNamespace
* nomad/csi_endpoint: ACL check
* nomad/state/state_store_test: remove call to state.CSIVolumes
* nomad/core_sched_test: job namespace match so claim gc works
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.
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.
Enable any Server to lookup the unique ClusterID. If one has not been
generated, and this node is the leader, generate a UUID and attempt to
apply it through raft.
The value is not yet used anywhere in this changeset, but is a prerequisite
for gh-6701.
This commit ensures that Alloc.AllocatedResources is properly populated
when read from persistence stores (namely Raft and client state store).
The alloc struct may have been written previously by an arbitrary old
version that may only populate Alloc.TaskResources.
Fix a case where `node.StatusUpdatedAt` was manipulated directly in
memory.
This ensures that StatusUpdatedAt is set in raft layer, and ensures that
the field is updated when node drain/eligibility is updated too.
Fixes https://github.com/hashicorp/nomad/issues/4299
Upon investigating this case further, we determined the issue to be a race between applying `JobBatchDeregisterRequest` fsm operation and processing job-deregister evals.
Processing job-deregister evals should wait until the FSM log message finishes applying, by using the snapshot index. However, with `JobBatchDeregister`, any single individual job deregistering was applied accidentally incremented the snapshot index and resulted into processing job-deregister evals. When a Nomad server receives an eval for a job in the batch that is yet to be deleted, we accidentally re-run it depending on the state of allocation.
This change ensures that we delete deregister all of the jobs and inserts all evals in a single transactions, thus blocking processing related evals until deregistering complete.
This commit implements an allocation selection algorithm for finding
allocations to preempt. It currently special cases network resource asks
from others (cpu/memory/disk/iops).
