PBM-1312: set default num-parallal-collection for restore to be (cpu/2)

Author: defbin

cmd/pbm-agent/restore.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"runtime"
 	"time"
 
 	"github.com/percona/percona-backup-mongodb/pbm/backup"
@@ -114,7 +115,7 @@ func (a *Agent) Restore(ctx context.Context, r *ctrl.RestoreCmd, opid ctrl.OPID,
 			return
 		}
 
-		var numParallelColls int
+		numParallelColls := runtime.NumCPU() / 2
 		if r.NumParallelColls != nil && *r.NumParallelColls > 0 {
 			numParallelColls = int(*r.NumParallelColls)
 		}

pbm/restore/logical.go

@@ -1193,7 +1193,7 @@ func (r *Restore) snapshot(ctx context.Context, input io.Reader) error {
 		return errors.Wrap(err, "unable to get PBM config settings")
 	}
 
-	rf, err := snapshot.NewRestore(r.brief.URI, cfg)
+	rf, err := snapshot.NewRestore(r.brief.URI, cfg, r.numParallelColls)
 	if err != nil {
 		return err
 	}

pbm/snapshot/restore.go

@@ -42,7 +42,7 @@ var ExcludeFromRestore = []string{
 
 type restorer struct{ *mongorestore.MongoRestore }
 
-func NewRestore(uri string, cfg *config.Config) (io.ReaderFrom, error) {
+func NewRestore(uri string, cfg *config.Config, numParallelColls int) (io.ReaderFrom, error) {
 	topts := options.New("mongorestore",
 		"0.0.1",
 		"none",
@@ -76,6 +76,9 @@ func NewRestore(uri string, cfg *config.Config) (io.ReaderFrom, error) {
 	if cfg.Restore.NumInsertionWorkers > 0 {
 		numInsertionWorkers = cfg.Restore.NumInsertionWorkers
 	}
+	if numParallelColls < 1 {
+		numParallelColls = 1
+	}
 
 	mopts := mongorestore.Options{}
 	mopts.ToolOptions = topts
@@ -87,6 +90,7 @@ func NewRestore(uri string, cfg *config.Config) (io.ReaderFrom, error) {
 		BypassDocumentValidation: true,
 		Drop:                     true,
 		NumInsertionWorkers:      numInsertionWorkers,
+		NumParallelCollections:   numParallelColls,
 		PreserveUUID:             preserveUUID,
 		StopOnError:              true,
 		WriteConcern:             "majority",