---
owner_slack: "#re-govuk"
title: Node classes without redundancy
layout: manual_layout
parent: "/manual.html"
section: Applications
important: true
last_reviewed_on: 2020-02-03
review_in: 6 months
---

Below we provide a list of node classes that are not configured to be highly available (HA). This means that short outages of these machines are architecturally considered acceptable.

Installation of a critical software component on a non-redundant node class has caused an incident in the past. This happened when `pgbouncer`, required for all Postgresql database accesses at the time, was installed on `db_admin`, a single EC2 instance. That single instance became unavailable and took down Postgres in Production.

**Please do not install new services or applications on any of the following machines unless it's OK for your service to be down 5% of the time:**

- db-admin
- transition-db-admin
- content-data-api-db-admin
- asset-master
- jumpbox
- ckan
- apt
- mirrorer
- licensing_backend

If in doubt, please discuss your requirements with RE GOV.UK (#re-govuk on Slack).

---
owner_slack: "#re-govuk"
title: Node classes without redundancy
layout: manual_layout
type: learn
parent: "/manual.html"
section: Applications
important: true
last_reviewed_on: 2020-02-03
review_in: 6 months
---

Below we provide a list of node classes that are not configured to be highly available (HA). This means that short outages of these machines are architecturally considered acceptable.

Installation of a critical software component on a non-redundant node class has caused an incident in the past. This happened when `pgbouncer`, required for all Postgresql database accesses at the time, was installed on `db_admin`, a single EC2 instance. That single instance became unavailable and took down Postgres in Production.

**Please do not install new services or applications on any of the following machines unless it's OK for your service to be down 5% of the time:**

- db-admin
- transition-db-admin
- content-data-api-db-admin
- asset-master
- jumpbox
- ckan
- apt
- mirrorer
- licensing_backend

If in doubt, please discuss your requirements with RE GOV.UK (#re-govuk on Slack).

Move "Node classes without redundancy" to Learn section
Move "Node classes without redundancy" to Learn section