﻿---
title: Bi-directional index following
description: In a bi-directional configuration, each cluster contains both leader and follower indices. When upgrading clusters in this configuration, pause all index...
url: https://www.elastic.co/elastic/docs-builder/docs/2541/deploy-manage/tools/cross-cluster-replication/ccr-bi-directional-upgrade
products:
  - Elasticsearch
applies_to:
  - Elastic Cloud Hosted: Generally available
  - Elastic Cloud on Kubernetes: Generally available in 3.0+
  - Elastic Cloud Enterprise: Generally available in 4.0+
  - Self-managed Elastic deployments: Generally available in 9.0+
---

# Bi-directional index following
In a bi-directional configuration, each cluster contains both leader and follower indices.
When upgrading clusters in this configuration, [pause all index following](https://www.elastic.co/elastic/docs-builder/docs/2541/deploy-manage/tools/cross-cluster-replication/ccr-pause-replication) and [pause auto-follow patterns](https://www.elastic.co/elastic/docs-builder/docs/2541/deploy-manage/tools/cross-cluster-replication/ccr-auto-follow-pause) prior to upgrading both clusters.
After upgrading both clusters, resume index following and resume replication of auto-follow patterns.