﻿---
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://docs-v3-preview.elastic.dev/elastic/docs-content/pull/4170/deploy-manage/tools/cross-cluster-replication/ccr-bi-directional-upgrade
products:
  - Elasticsearch
---

# 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://docs-v3-preview.elastic.dev/elastic/docs-content/pull/4170/deploy-manage/tools/cross-cluster-replication/ccr-pause-replication) and [pause auto-follow patterns](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/4170/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.