package dispatchcloud
import (
- "bytes"
"errors"
- "log"
- "os/exec"
- "strings"
- "time"
+ "sort"
"git.curoverse.com/arvados.git/sdk/go/arvados"
)
-var (
- ErrConstraintsNotSatisfiable = errors.New("constraints not satisfiable by any configured instance type")
- ErrInstanceTypesNotConfigured = errors.New("site configuration does not list any instance types")
- discountConfiguredRAMPercent = 5
-)
+var ErrInstanceTypesNotConfigured = errors.New("site configuration does not list any instance types")
+
+var discountConfiguredRAMPercent = 5
+
+// ConstraintsNotSatisfiableError includes a list of available instance types
+// to be reported back to the user.
+type ConstraintsNotSatisfiableError struct {
+ error
+ AvailableTypes []arvados.InstanceType
+}
// ChooseInstanceType returns the cheapest available
// arvados.InstanceType big enough to run ctr.
needRAM := ctr.RuntimeConstraints.RAM + ctr.RuntimeConstraints.KeepCacheRAM
needRAM = (needRAM * 100) / int64(100-discountConfiguredRAMPercent)
- err = ErrConstraintsNotSatisfiable
+ ok := false
for _, it := range cc.InstanceTypes {
switch {
- case err == nil && it.Price > best.Price:
- case it.Scratch < needScratch:
- case it.RAM < needRAM:
+ case ok && it.Price > best.Price:
+ case int64(it.Scratch) < needScratch:
+ case int64(it.RAM) < needRAM:
case it.VCPUs < needVCPUs:
+ case it.Preemptible != ctr.SchedulingParameters.Preemptible:
case it.Price == best.Price && (it.RAM < best.RAM || it.VCPUs < best.VCPUs):
// Equal price, but worse specs
default:
// Lower price || (same price && better specs)
best = it
- err = nil
+ ok = true
}
}
- return
-}
-
-// SlurmNodeTypeFeatureKludge ensures SLURM accepts every instance
-// type name as a valid feature name, even if no instances of that
-// type have appeared yet.
-//
-// It takes advantage of some SLURM peculiarities:
-//
-// (1) A feature is valid after it has been offered by a node, even if
-// it is no longer offered by any node. So, to make a feature name
-// valid, we can add it to a dummy node ("compute0"), then remove it.
-//
-// (2) To test whether a set of feature names are valid without
-// actually submitting a job, we can call srun --test-only with the
-// desired features.
-//
-// SlurmNodeTypeFeatureKludge does a test-and-fix operation
-// immediately, and then periodically, in case slurm restarts and
-// forgets the list of valid features. It never returns (unless there
-// are no node types configured, in which case it returns
-// immediately), so it should generally be invoked with "go".
-func SlurmNodeTypeFeatureKludge(cc *arvados.Cluster) {
- if len(cc.InstanceTypes) == 0 {
- return
- }
- var features []string
- for _, it := range cc.InstanceTypes {
- features = append(features, "instancetype="+it.Name)
- }
- for {
- slurmKludge(features)
- time.Sleep(time.Minute)
- }
-}
-
-var (
- slurmDummyNode = "compute0"
- slurmErrBadFeature = "Invalid feature"
- slurmErrNoNodes = "node configuration is not available"
-)
-
-func slurmKludge(features []string) {
- cmd := exec.Command("srun", "--test-only", "--constraint="+strings.Join(features, "&"), "false")
- out, err := cmd.CombinedOutput()
- switch {
- case err == nil || bytes.Contains(out, []byte(slurmErrNoNodes)):
- // Evidently our node-type feature names are all valid.
-
- case bytes.Contains(out, []byte(slurmErrBadFeature)):
- log.Printf("temporarily configuring node %q with all node type features", slurmDummyNode)
- for _, nodeFeatures := range []string{strings.Join(features, ","), ""} {
- cmd = exec.Command("scontrol", "update", "NodeName="+slurmDummyNode, "Features="+nodeFeatures)
- log.Printf("running: %q %q", cmd.Path, cmd.Args)
- out, err := cmd.CombinedOutput()
- if err != nil {
- log.Printf("error: scontrol: %s (output was %q)", err, out)
- }
+ if !ok {
+ availableTypes := make([]arvados.InstanceType, 0, len(cc.InstanceTypes))
+ for _, t := range cc.InstanceTypes {
+ availableTypes = append(availableTypes, t)
}
-
- default:
- log.Printf("warning: expected srun error %q, %q, or success, but output was %q", slurmErrBadFeature, slurmErrNoNodes, out)
+ sort.Slice(availableTypes, func(a, b int) bool {
+ return availableTypes[a].Price < availableTypes[b].Price
+ })
+ err = ConstraintsNotSatisfiableError{
+ errors.New("constraints not satisfiable by any configured instance type"),
+ availableTypes,
+ }
+ return
}
+ return
}