Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[scheduler] Honor false for distinct hosts constraint #16907

Merged
merged 4 commits into from
Apr 17, 2023
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions .changelog/16907.txt
Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
```release-note:bug
scheduler: honor false value for distinct_hosts constraint
```
5 changes: 4 additions & 1 deletion jobspec2/hcl_conversions.go
Original file line number Diff line number Diff line change
Expand Up @@ -235,8 +235,11 @@ func decodeConstraint(body hcl.Body, ctx *hcl.EvalContext, val interface{}) hcl.
c.RTarget = constraint
}

if d := v.GetAttr(api.ConstraintDistinctHosts); !d.IsNull() && d.True() {
// The shortcut form of the distinct_hosts constraint is a cty.Bool
// so it can not use the `attr` func defined earlier
if d := v.GetAttr(api.ConstraintDistinctHosts); !d.IsNull() {
c.Operand = api.ConstraintDistinctHosts
c.RTarget = fmt.Sprint(d.True())
}

if property := attr(api.ConstraintDistinctProperty); property != "" {
Expand Down
9 changes: 8 additions & 1 deletion scheduler/feasible.go
Original file line number Diff line number Diff line change
Expand Up @@ -572,7 +572,14 @@ func (iter *DistinctHostsIterator) SetJob(job *structs.Job) {
func (iter *DistinctHostsIterator) hasDistinctHostsConstraint(constraints []*structs.Constraint) bool {
for _, con := range constraints {
if con.Operand == structs.ConstraintDistinctHosts {
return true
// distinct_hosts defaults to true
if con.RTarget == "" {
return true
}
enabled, err := strconv.ParseBool(con.RTarget)
// If the value is unparsable as a boolean, fall back to the old behavior
// of enforcing the constraint when it appears.
return err != nil || enabled
}
}

Expand Down
99 changes: 99 additions & 0 deletions scheduler/feasible_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -1437,6 +1437,105 @@ func TestDistinctHostsIterator_JobDistinctHosts(t *testing.T) {
}
}

func TestDistinctHostsIterator_JobDistinctHosts_Table(t *testing.T) {
ci.Parallel(t)

// Create a job with a distinct_hosts constraint and a task group.
tg1 := &structs.TaskGroup{Name: "bar"}
job := &structs.Job{
ID: "foo",
Namespace: structs.DefaultNamespace,
Constraints: []*structs.Constraint{{
Operand: structs.ConstraintDistinctHosts,
}},
TaskGroups: []*structs.TaskGroup{tg1},
}
makeJobAllocs := func(js []*structs.Job) []*structs.Allocation {
na := make([]*structs.Allocation, len(js))
for i, j := range js {
allocID := uuid.Generate()
na[i] = &structs.Allocation{
Namespace: structs.DefaultNamespace,
TaskGroup: j.TaskGroups[0].Name,
JobID: j.ID,
Job: j,
ID: allocID,
}
}
return na
}

n1 := mock.Node()
n2 := mock.Node()
n3 := mock.Node()

testCases := []struct {
name string
RTarget string
expectLen int
expectNodes []*structs.Node
}{
{
name: "unset",
RTarget: "",
expectLen: 1,
expectNodes: []*structs.Node{n3},
},
{
name: "true",
RTarget: "true",
expectLen: 1,
expectNodes: []*structs.Node{n3},
},
{
name: "false",
RTarget: "false",
expectLen: 3,
expectNodes: []*structs.Node{n1, n2, n3},
},
{
name: "unparsable",
RTarget: "not_a_bool",
expectLen: 1,
expectNodes: []*structs.Node{n3},
},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
tc := tc
ci.Parallel(t)

_, ctx := testContext(t)
static := NewStaticIterator(ctx, []*structs.Node{n1, n2, n3})

j := job.Copy()
j.Constraints[0].RTarget = tc.RTarget

oj := j.Copy()
oj.ID = "otherJob"

plan := ctx.Plan()
// Add allocations so that some of the nodes will be ineligible
// to receive the job when the distinct_hosts constraint
// is active. This will require the job be placed on n3.
//
// Another job is placed on all of the nodes to ensure that there
// are no unexpected interactions.
plan.NodeAllocation[n1.ID] = makeJobAllocs([]*structs.Job{j, oj})
plan.NodeAllocation[n2.ID] = makeJobAllocs([]*structs.Job{j, oj})
plan.NodeAllocation[n3.ID] = makeJobAllocs([]*structs.Job{oj})

proposed := NewDistinctHostsIterator(ctx, static)
proposed.SetTaskGroup(tg1)
proposed.SetJob(j)

out := collectFeasible(proposed)
must.Len(t, tc.expectLen, out, must.Sprintf("Bad: %v", out))
must.SliceContainsAll(t, tc.expectNodes, out)
})
}
}

func TestDistinctHostsIterator_JobDistinctHosts_InfeasibleCount(t *testing.T) {
ci.Parallel(t)

Expand Down