"errors"
"log"
"os/exec"
+ "regexp"
+ "sort"
+ "strconv"
"strings"
"time"
)
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
)
+// ConstraintsNotSatisfiableError includes a list of available instance types
+// to be reported back to the user.
+type ConstraintsNotSatisfiableError struct {
+ error
+ AvailableTypes []arvados.InstanceType
+}
+
+var pdhRegexp = regexp.MustCompile(`^[0-9a-f]{32}\+(\d+)$`)
+
+// estimateDockerImageSize estimates how much disk space will be used
+// by a Docker image, given the PDH of a collection containing a
+// Docker image that was created by "arv-keepdocker". Returns
+// estimated number of bytes of disk space that should be reserved.
+func estimateDockerImageSize(collectionPDH string) int64 {
+ m := pdhRegexp.FindStringSubmatch(collectionPDH)
+ if m == nil {
+ log.Printf("estimateDockerImageSize: '%v' did not match pdhRegexp, returning 0", collectionPDH)
+ return 0
+ }
+ n, err := strconv.ParseInt(m[1], 10, 64)
+ if err != nil || n < 122 {
+ log.Printf("estimateDockerImageSize: short manifest %v or error (%v), returning 0", n, err)
+ return 0
+ }
+ // To avoid having to fetch the collection, take advantage of
+ // the fact that the manifest storing a container image
+ // uploaded by arv-keepdocker has a predictable format, which
+ // allows us to estimate the size of the image based on just
+ // the size of the manifest.
+ //
+ // Use the following heuristic:
+ // - Start with the length of the mainfest (n)
+ // - Subtract 80 characters for the filename and file segment
+ // - Divide by 42 to get the number of block identifiers ('hash\+size\ ' is 32+1+8+1)
+ // - Assume each block is full, multiply by 64 MiB
+ return ((n - 80) / 42) * (64 * 1024 * 1024)
+}
+
+// EstimateScratchSpace estimates how much available disk space (in
+// bytes) is needed to run the container by summing the capacity
+// requested by 'tmp' mounts plus disk space required to load the
+// Docker image.
+func EstimateScratchSpace(ctr *arvados.Container) (needScratch int64) {
+ for _, m := range ctr.Mounts {
+ if m.Kind == "tmp" {
+ needScratch += m.Capacity
+ }
+ }
+
+ // Account for disk space usage by Docker, assumes the following behavior:
+ // - Layer tarballs are buffered to disk during "docker load".
+ // - Individual layer tarballs are extracted from buffered
+ // copy to the filesystem
+ dockerImageSize := estimateDockerImageSize(ctr.ContainerImage)
+
+ // The buffer is only needed during image load, so make sure
+ // the baseline scratch space at least covers dockerImageSize,
+ // and assume it will be released to the job afterwards.
+ if needScratch < dockerImageSize {
+ needScratch = dockerImageSize
+ }
+
+ // Now reserve space for the extracted image on disk.
+ needScratch += dockerImageSize
+
+ return
+}
+
// ChooseInstanceType returns the cheapest available
// arvados.InstanceType big enough to run ctr.
func ChooseInstanceType(cc *arvados.Cluster, ctr *arvados.Container) (best arvados.InstanceType, err error) {
return
}
- needScratch := int64(0)
- for _, m := range ctr.Mounts {
- if m.Kind == "tmp" {
- needScratch += m.Capacity
- }
- }
+ needScratch := EstimateScratchSpace(ctr)
needVCPUs := ctr.RuntimeConstraints.VCPUs
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
}
}
+ if !ok {
+ availableTypes := make([]arvados.InstanceType, 0, len(cc.InstanceTypes))
+ for _, t := range cc.InstanceTypes {
+ availableTypes = append(availableTypes, t)
+ }
+ 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
}