Adds a new Prerun and Postrun hooks to manage set up of network namespaces
on linux. Work still needs to be done to make the code platform agnostic and
support Docker style network initalization.
When an alloc is due to be rescheduleLater, it goes through the
reconciler twice: once to be ignored with a follow up evals, and once
again when processing the follow up eval where they appear as
rescheduleNow.
Here, we ignore them in the first run and mark them as stopped in second
iteration; rather than stop them twice.
Currently, when an alloc fails and is rescheduled, the alloc desired
state remains as "run" and the nomad client may not free the resources.
Here, we ensure that an alloc is marked as stopped when it's
rescheduled.
Notice the Desired Status and Description before and after this change:
Before:
```
mars-2:nomad notnoop$ nomad alloc status 02aba49e
ID = 02aba49e
Eval ID = bb9ed1d2
Name = example-reschedule.nodes[0]
Node ID = 5853d547
Node Name = mars-2.local
Job ID = example-reschedule
Job Version = 0
Client Status = failed
Client Description = Failed tasks
Desired Status = run
Desired Description = <none>
Created = 10s ago
Modified = 5s ago
Replacement Alloc ID = d6bf872b
Task "payload" is "dead"
Task Resources
CPU Memory Disk Addresses
0/100 MHz 24 MiB/300 MiB 300 MiB
Task Events:
Started At = 2019-06-06T21:12:45Z
Finished At = 2019-06-06T21:12:50Z
Total Restarts = 0
Last Restart = N/A
Recent Events:
Time Type Description
2019-06-06T17:12:50-04:00 Not Restarting Policy allows no restarts
2019-06-06T17:12:50-04:00 Terminated Exit Code: 1
2019-06-06T17:12:45-04:00 Started Task started by client
2019-06-06T17:12:45-04:00 Task Setup Building Task Directory
2019-06-06T17:12:45-04:00 Received Task received by client
```
After:
```
ID = 5001ccd1
Eval ID = 53507a02
Name = example-reschedule.nodes[0]
Node ID = a3b04364
Node Name = mars-2.local
Job ID = example-reschedule
Job Version = 0
Client Status = failed
Client Description = Failed tasks
Desired Status = stop
Desired Description = alloc was rescheduled because it failed
Created = 13s ago
Modified = 3s ago
Replacement Alloc ID = 7ba7ac20
Task "payload" is "dead"
Task Resources
CPU Memory Disk Addresses
21/100 MHz 24 MiB/300 MiB 300 MiB
Task Events:
Started At = 2019-06-06T21:22:50Z
Finished At = 2019-06-06T21:22:55Z
Total Restarts = 0
Last Restart = N/A
Recent Events:
Time Type Description
2019-06-06T17:22:55-04:00 Not Restarting Policy allows no restarts
2019-06-06T17:22:55-04:00 Terminated Exit Code: 1
2019-06-06T17:22:50-04:00 Started Task started by client
2019-06-06T17:22:50-04:00 Task Setup Building Task Directory
2019-06-06T17:22:50-04:00 Received Task received by client
```
Fix `TestServiceSched_NodeDown` for checking that the migrated allocs
are actually marked to be stopped.
The boolean logic in test made it skip actually checking client status
as long as desired status was stop.
Here, we mark some jobs for migration while leaving others as running,
and we check that lost flag is only set for non-migrated allocs.
This adds a `nomad alloc stop` command that can be used to stop and
force migrate an allocation to a different node.
This is built on top of the AllocUpdateDesiredTransitionRequest and
explicitly limits the scope of access to that transition to expose it
under the alloc-lifecycle ACL.
The API returns the follow up eval that can be used as part of
monitoring in the CLI or parsed and used in an external tool.
Currently when operators need to log onto a machine where an alloc
is running they will need to perform both an alloc/job status
call and then a call to discover the node name from the node list.
This updates both the job status and alloc status output to include
the node name within the information to make operator use easier.
Closes#2359
Cloess #1180
IOPS have been modelled as a resource since Nomad 0.1 but has never
actually been detected and there is no plan in the short term to add
detection. This is because IOPS is a bit simplistic of a unit to define
the performance requirements from the underlying storage system. In its
current state it adds unnecessary confusion and can be removed without
impacting any users. This PR leaves IOPS defined at the jobspec parsing
level and in the api/ resources since these are the two public uses of
the field. These should be considered deprecated and only exist to allow
users to stop using them during the Nomad 0.9.x release. In the future,
there should be no expectation that the field will exist.
This adds constraints for asserting that a given attribute or value
exists, or does not exist. This acts as a companion to =, or !=
operators, e.g:
```hcl
constraint {
attribute = "${attrs.type}"
operator = "!="
value = "database"
}
constraint {
attribute = "${attrs.type}"
operator = "is_set"
}
```
This commit allows the ConstraintChecker to test values that do not exist.
This is useful when wanting to _exclude_ given nodes from executing a
job, for example, if you wanted to give canary nodes an attribute, and
not run critical services on them, you may specify something like the
below, but not want to tag all other nodes with the inverse.
```hcl
constraint {
attribute = "${node.attr.canary}
operator = "!="
value = "1"
}
```
This also requires all constraint checkers to allow for nil target
values, as they will no longer be short circuited by resolving a target.
Also changes the logic for score when there is more than one task
requesting a device. Since inter task affinities are already normalized,
we take the average of the scores across tasks.
The old logic for cancelling duplicate blocked evaluations by job id had
the issue where the newer evaluation could have additional node classes
that it is (in)eligible for that we would not capture. This could make
it such that cluster state could change such that the job would make
progress but no evaluation was unblocked.
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).
This PR changes behavior of the scheduler such that a task group with a
deployment that is failed or paused will not cause the scheduler to skip
migrations.
The reason for this change is that it causes a bad UX when draining
nodes with allocations that are part of a failed/paused deployment.
These operations should not be coupled in any way and this remedies
that.
Prior behavior was still correct, but required either jobs to
transistion to a healthy state or for the node to hit its drain
deadline.
Nick Ethier