limit concurrent slurm commands

[arvados.git] / services / crunch-dispatch-slurm / slurm.go

diff --git a/services/crunch-dispatch-slurm/slurm.go b/services/crunch-dispatch-slurm/slurm.go
index 9e9f45270f82d3450d27e380fe63924177e5501d..782be7d8c4e7226ced947bcd26c983ecb6b31de3 100644 (file)
--- a/services/crunch-dispatch-slurm/slurm.go
+++ b/services/crunch-dispatch-slurm/slurm.go
@@ -20,7 +20,15 @@ type Slurm interface {
        Renice(name string, nice int64) error
 }
 
-type slurmCLI struct{}
+type slurmCLI struct{
+       runSemaphore chan bool
+}
+
+func NewSlurmCLI() *slurmCLI {
+       return &slurmCLI{
+              runSemaphore: make(chan bool, 3),
+       }
+}
 
 func (scli *slurmCLI) Batch(script io.Reader, args []string) error {
        return scli.run(script, "sbatch", args)
@@ -64,6 +72,8 @@ func (scli *slurmCLI) Renice(name string, nice int64) error {
 }
 
 func (scli *slurmCLI) run(stdin io.Reader, prog string, args []string) error {
+       scli.runSemaphore <- true
+       defer func() { <-scli.runSemaphore }()
        cmd := exec.Command(prog, args...)
        cmd.Stdin = stdin
        out, err := cmd.CombinedOutput()