Nit: unify the default `--maxParallelization` value for `weed shell` commands supporting this option (#6788)

weed/shell/command_ec_balance.go

@@ -35,7 +35,7 @@ func (c *commandEcBalance) Do(args []string, commandEnv *CommandEnv, writer io.W
 	collection := balanceCommand.String("collection", "EACH_COLLECTION", "collection name, or \"EACH_COLLECTION\" for each collection")
 	dc := balanceCommand.String("dataCenter", "", "only apply the balancing for this dataCenter")
 	shardReplicaPlacement := balanceCommand.String("shardReplicaPlacement", "", "replica placement for EC shards, or master default if empty")
-	maxParallelization := balanceCommand.Int("maxParallelization", 10, "run up to X tasks in parallel, whenever possible")
+	maxParallelization := balanceCommand.Int("maxParallelization", DefaultMaxParallelization, "run up to X tasks in parallel, whenever possible")
 	applyBalancing := balanceCommand.Bool("force", false, "apply the balancing plan")
 	if err = balanceCommand.Parse(args); err != nil {
 		return nil

weed/shell/command_ec_encode.go

@@ -66,7 +66,7 @@ func (c *commandEcEncode) Do(args []string, commandEnv *CommandEnv, writer io.Wr
 	collection := encodeCommand.String("collection", "", "the collection name")
 	fullPercentage := encodeCommand.Float64("fullPercent", 95, "the volume reaches the percentage of max volume size")
 	quietPeriod := encodeCommand.Duration("quietFor", time.Hour, "select volumes without no writes for this period")
-	maxParallelization := encodeCommand.Int("maxParallelization", 10, "run up to X tasks in parallel, whenever possible")
+	maxParallelization := encodeCommand.Int("maxParallelization", DefaultMaxParallelization, "run up to X tasks in parallel, whenever possible")
 	forceChanges := encodeCommand.Bool("force", false, "force the encoding even if the cluster has less than recommended 4 nodes")
 	shardReplicaPlacement := encodeCommand.String("shardReplicaPlacement", "", "replica placement for EC shards, or master default if empty")
 	applyBalancing := encodeCommand.Bool("rebalance", false, "re-balance EC shards after creation")

weed/shell/common.go

@@ -5,6 +5,11 @@ import (
 	"sync"
 )
 
+var (
+	// Default maximum parallelization/concurrency for commands supporting it.
+	DefaultMaxParallelization = 10
+)
+
 // ErrorWaitGroup implements a goroutine wait group which aggregates errors, if any.
 type ErrorWaitGroup struct {
 	maxConcurrency int