perf: set ResourceVersion=0 in deleteTaskResults to reduce etcd pressure. (cherry-pick #15115 for 3.7) (#15151)

Signed-off-by: shuangkun <[email protected]>
Co-authored-by: shuangkun tian <[email protected]>
Co-authored-by: Alan Clucas <[email protected]>

Author: 3 people

workflow/controller/operator.go

@@ -834,7 +834,13 @@ func (woc *wfOperationCtx) deleteTaskResults(ctx context.Context) error {
 		DeleteCollection(
 			ctx,
 			metav1.DeleteOptions{PropagationPolicy: &deletePropagationBackground},
-			metav1.ListOptions{LabelSelector: common.LabelKeyWorkflow + "=" + woc.wf.Name},
+			metav1.ListOptions{
+				LabelSelector: common.LabelKeyWorkflow + "=" + woc.wf.Name,
+				// DeleteCollection does a "list" operation to get the resources to delete, which by default does a strongly consistent read of the most recent version.
+				// This can be slow for Kubernetes versions before 1.34, so we set resourceVersion=0 to relax consistency and tell the k8s API to return any resource version.
+				// It's possible for this to miss some resources, but those should be GC'd when the parent workflow is deleted.
+				ResourceVersion: "0",
+			},
 		)
 }