From 07f6c4ac592ebbba90fd15214bf69a80145acf0d Mon Sep 17 00:00:00 2001 From: Patrick Devine Date: Tue, 7 Feb 2017 16:44:57 -0800 Subject: [PATCH] Add storage section and clarify sizing guidelines --- .../dtr/2.1/guides/high-availability/index.md | 27 ++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/datacenter/dtr/2.1/guides/high-availability/index.md b/datacenter/dtr/2.1/guides/high-availability/index.md index 67126e1332..130bf8a716 100644 --- a/datacenter/dtr/2.1/guides/high-availability/index.md +++ b/datacenter/dtr/2.1/guides/high-availability/index.md @@ -34,11 +34,15 @@ the DTR cluster. When sizing your DTR installation for high-availability, follow these rules of thumb: -* Don't create a DTR cluster with just two replicas. Your cluster -won't tolerate any failures, and it's possible that you experience performance -degradation. +* Don't create a DTR cluster with an even number replicas. Your cluster +won't tolerate any failures if the cluster splits in half. This is +very difficult to recover from. * When a replica fails, the number of failures tolerated by your cluster decreases. Don't leave that replica offline for long. +* When you want to fix your DTR cluster, make certain that you remove any +broken replicas before you try to add a new replica. The DTR bootstrapper +will try to prevent you from doing this, as it could lead to multiple +failed nodes and failure of the entire DTR cluster. * Adding too many replicas to the cluster might also lead to performance degradation, as data needs to be replicated across all replicas. @@ -64,6 +68,23 @@ To have high-availability on UCP and DTR, you need a minimum of: ![](../images/high-availability-2.png) +## Storage considerations + +DTR does not provide clustering for the storage which underlies your image +repositories. In order for DTR to work correctly in HA mode, you will either +need to use object storage or NFS. + +Supported object stores include: + +* AWS S3 +* Azure Cloud Storage +* OpenStack Swift +* Google Cloud Storage +* S3 Compatible storage (Scality, Minio, etc.) + +Object storage can be configured directly through the Admin screen in the +DTR UI, and NFS can be configured during installation through the CLI. + ## Load balancing DTR does not provide a load balancing service. You can use an on-premises