:_mod-docs-content-type: ASSEMBLY

// This assembly is included in the following assemblies:
//
// assembly-config.adoc

[id='assembly-using-multiple-cluster-operator-replicas-{context}']
= Running multiple Cluster Operator replicas with leader election

[role="_abstract"]
The default Cluster Operator configuration enables leader election to run multiple parallel replicas of the Cluster Operator.
One replica is elected as the active leader and operates the deployed resources.
The other replicas run in standby mode.
When the leader stops or fails, one of the standby replicas is elected as the new leader and starts operating the deployed resources.

By default, Strimzi runs with a single Cluster Operator replica that is always the leader replica. 
When a single Cluster Operator replica stops or fails, Kubernetes starts a new replica.

Running the Cluster Operator with multiple replicas is not essential.
But it's useful to have replicas on standby in case of large-scale disruptions caused by major failure. 
For example, suppose multiple worker nodes or an entire availability zone fails. 
This failure might cause the Cluster Operator pod and many Kafka pods to go down at the same time.  
If subsequent pod scheduling causes congestion through lack of resources, this can delay operations when running a single Cluster Operator.  

//cluster operator config for leader election
include::../../modules/operators/con-configuring-cluster-operator-leader-election.adoc[leveloffset=+1]
// Configuring Cluster Operator replicas
include::../../modules/operators/proc-configuring-multiple-cluster-operators.adoc[leveloffset=+1]