Change default stress batch size to 5000

10000 is too large and causes a lot of allocations.  5000 doubles the
throughput.

stress/stress_test.go

@@ -554,8 +554,8 @@ func Test_NewConfigWithoutFile(t *testing.T) {
 	if wc.Precision != "n" {
 		t.Errorf("Expected n got %s", wc.Precision)
 	}
-	if wc.BatchSize != 10000 {
-		t.Errorf("Expected 10000 got %v", wc.BatchSize)
+	if wc.BatchSize != 5000 {
+		t.Errorf("Expected 5000 got %v", wc.BatchSize)
 	}
 	if wc.BatchInterval != "0s" {
 		t.Errorf("Expected 0s got %v", wc.BatchInterval)

stress/template.go

@@ -36,7 +36,7 @@ var s = `
       address = "localhost:8086"
       database = "stress"
       precision = "n"
-      batch_size = 10000
+      batch_size = 5000
       batch_interval = "0s"
       concurrency = 10
       ssl = false