This change isolates all the code that deals with node selection in the
scheduler into its own package called feasible.
---------
Co-authored-by: Tim Gross <tgross@hashicorp.com>
In the spirit of #25909, this PR removes testify dependencies from the scheduler
package, along with reflect.DeepEqual removal. This is again a combination of
semgrep and hx editing magic.
---------
Co-authored-by: Tim Gross <tgross@hashicorp.com>
* Only error on constraints if no allocs are running
When running `nomad job run <JOB>` multiple times with constraints
defined, there should be no error as a result of filtering out nodes
that do not/have not ever satsified the constraints.
When running a systems job with constraint, any run after an initial
startup returns an exit(2) and a warning about unplaced allocations due
to constraints. An error that is not encountered on the initial run,
though the constraint stays the same.
This is because the node that satisfies the condition is already running
the allocation, and the placement is ignored. Another placement is
attempted, but the only node(s) left are the ones that do not satisfy
the constraint. Nomad views this case (no allocations that were
attempted to placed could be placed successfully) as an error, and
reports it as such. In reality, no allocations should be placed or
updated in this case, but it should not be treated as an error.
This change uses the `ignored` placements from diffSystemAlloc to attempt to
determine if the case encountered is an error (no ignored placements
means that nothing is already running, and is an error), or is not one
(an ignored placement means that the task is already running somewhere
on a node). It does this at the point where `failedTGAlloc` is
populated, so placement functionality isn't changed, just the field that
populates error.
There is functionality that should be preserved which (correctly)
notifies a user if a job is attempted that cannot be run on any node due
to the constraints filtering out all available nodes. This should still
behave as expected.
* Add changelog entry
* Handle in-place updates for constrained system jobs
* Update .changelog/25850.txt
Co-authored-by: Piotr Kazmierczak <470696+pkazmierczak@users.noreply.github.com>
* Remove conditionals
---------
Co-authored-by: Piotr Kazmierczak <470696+pkazmierczak@users.noreply.github.com>
* core: plumbing to support numa aware scheduling
* core: apply node resources compatibility upon fsm rstore
Handle the case where an upgraded server dequeus an evaluation before
a client triggers a new fingerprint - which would be needed to cause
the compatibility fix to run. By running the compat fix on restore the
server will immediately have the compatible pseudo topology to use.
* lint: learn how to spell pseudo
Implement scheduler support for node pool:
* When a scheduler is invoked, we get a set of the ready nodes in the DCs that
are allowed for that job. Extend the filter to include the node pool.
* Ensure that changes to a job's node pool are picked up as destructive
allocation updates.
* Add `NodesInPool` as a metric to all reporting done by the scheduler.
* Add the node-in-pool the filter to the `Node.Register` RPC so that we don't
generate spurious evals for nodes in the wrong pool.
* api: enable support for setting original source alongside job
This PR adds support for setting job source material along with
the registration of a job.
This includes a new HTTP endpoint and a new RPC endpoint for
making queries for the original source of a job. The
HTTP endpoint is /v1/job/<id>/submission?version=<version> and
the RPC method is Job.GetJobSubmission.
The job source (if submitted, and doing so is always optional), is
stored in the job_submission memdb table, separately from the
actual job. This way we do not incur overhead of reading the large
string field throughout normal job operations.
The server config now includes job_max_source_size for configuring
the maximum size the job source may be, before the server simply
drops the source material. This should help prevent Bad Things from
happening when huge jobs are submitted. If the value is set to 0,
all job source material will be dropped.
* api: avoid writing var content to disk for parsing
* api: move submission validation into RPC layer
* api: return an error if updating a job submission without namespace or job id
* api: be exact about the job index we associate a submission with (modify)
* api: reword api docs scheduling
* api: prune all but the last 6 job submissions
* api: protect against nil job submission in job validation
* api: set max job source size in test server
* api: fixups from pr
Service jobs should have unique allocation Names, derived from the
Job.ID. System jobs do not have unique allocation Names because the index is
intended to indicated the instance out of a desired count size. Because system
jobs do not have an explicit count but the results are based on the targeted
nodes, the index is less informative and this was intentionally omitted from the
original design.
Update docs to make it clear that NOMAD_ALLOC_INDEX is always zero for
system/sysbatch jobs
Validate that `volume.per_alloc` is incompatible with system/sysbatch jobs.
System and sysbatch jobs always have a `NOMAD_ALLOC_INDEX` of 0. So
interpolation via `per_alloc` will not work as soon as there's more than one
allocation placed. Validate against this on job submission.
When a system or sysbatch job specify constraints that none of the
current nodes meet, report a warning to the user.
Also, for sysbatch job, mark the job as dead as a result.
A sample run would look like:
```
$ nomad job run ./example.nomad
==> 2021-08-31T16:57:35-04:00: Monitoring evaluation "b48e8882"
2021-08-31T16:57:35-04:00: Evaluation triggered by job "example"
==> 2021-08-31T16:57:36-04:00: Monitoring evaluation "b48e8882"
2021-08-31T16:57:36-04:00: Evaluation status changed: "pending" -> "complete"
==> 2021-08-31T16:57:36-04:00: Evaluation "b48e8882" finished with status "complete" but failed to place all allocations:
2021-08-31T16:57:36-04:00: Task Group "cache" (failed to place 1 allocation):
* Constraint "${meta.tag} = bar": 2 nodes excluded by filter
* Constraint "${attr.kernel.name} = linux": 1 nodes excluded by filter
$ nomad job status example
ID = example
Name = example
Submit Date = 2021-08-31T16:57:35-04:00
Type = sysbatch
Priority = 50
Datacenters = dc1
Namespace = default
Status = dead
Periodic = false
Parameterized = false
Summary
Task Group Queued Starting Running Failed Complete Lost
cache 0 0 0 0 0 0
Allocations
No allocations placed
```
This PR implements a new "System Batch" scheduler type. Jobs can
make use of this new scheduler by setting their type to 'sysbatch'.
Like the name implies, sysbatch can be thought of as a hybrid between
system and batch jobs - it is for running short lived jobs intended to
run on every compatible node in the cluster.
As with batch jobs, sysbatch jobs can also be periodic and/or parameterized
dispatch jobs. A sysbatch job is considered complete when it has been run
on all compatible nodes until reaching a terminal state (success or failed
on retries).
Feasibility and preemption are governed the same as with system jobs. In
this PR, the update stanza is not yet supported. The update stanza is sill
limited in functionality for the underlying system scheduler, and is
not useful yet for sysbatch jobs. Further work in #4740 will improve
support for the update stanza and deployments.
Closes#2527
