---
layout: docs
page_title: high_availability Block - Nomad Autoscaler Agent Configuration
description: >-
  The "high_availability" block is used to configure the Nomad Autoscaler agent
  in high availability (HA) mode. In this mode, multiple agents participate in
  leadership election, with only the leader conducting autoscaling calculations
  and actions.
---

# `high_availability` Block

<Placement groups={['high_availability']} />

The `high_availability` block is used to configure the Nomad Autoscaler agent
in high availability (HA) mode. In this mode, multiple agents participate in
leadership election, with only the leader conducting autoscaling calculations
and actions.

```hcl
high_availability {
  enabled        = true
  lock_namespace = "prod"
  lock_path      = "custom/lock/path"
  lock_ttl       = "30s"
  lock_delay     = "15s"
}
```

## `high_availability` Parameters

- `enabled` `(bool: false)` - Specifies whether the Nomad Autoscaler agent will
  start in high availability mode. If enabled, the agent instance attempts to
  hold a lock over a Nomad variable and will only execute if the lock is
  successfully acquired.

- `lock_namespace` `(string: "default")` - Defines the namespace of the Nomad
  variable that will be used to sync the leader when running in high
  availability mode. This parameter needs to be the same on all Nomad
  Autoscaler agents expected to take part in the same leadership election
  process.

- `lock_path` `(string: "nomad-autoscaler/lock")` - Defines the path of the Nomad
  variable that will be used to sync the leader when running in high
  availability mode. This parameter needs to be the same on all Nomad Autoscaler
  agents expected to take part in the same leadership election process.

- `lock_ttl` `(string: "60s")` - Defines the lease period or TTL of the lock used
  to sync the leader when running in high availability mode. If the Nomad Autoscaler
  agent does not renew the lock within this period, the lock is considered lost.

- `lock_delay` `(string: "30s")` - Defines the period that the lock will be blocked
  after the TTL expired without being renewed. This helps prevent split brain
  situations.
