From e1e21944ac57319e87a0b3f0e0635bbc31370fd8 Mon Sep 17 00:00:00 2001 From: Lance Leonard Date: Wed, 14 Jul 2021 09:06:09 -0700 Subject: [PATCH] Jira DOC-814: RC - Clarify high-availability article (#1448) * Quick edits to rework plan names. * Initial draft of updates. --- content/rc/databases/high-availability.md | 26 +++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/content/rc/databases/high-availability.md b/content/rc/databases/high-availability.md index 22cf03e4ea4..64a3cab65bc 100644 --- a/content/rc/databases/high-availability.md +++ b/content/rc/databases/high-availability.md @@ -11,25 +11,39 @@ aliases: Database replication helps ensure high availability. When replication is enabled, your dataset is duplicated to create a replica, which stays in sync with the primary dataset. Replication allows for automatic failover and greater fault tolerance. This can prevent data loss in the event of a hardware or zone failure. +## Options and plan support + Redis Enterprise Cloud supports three levels of replication: - _No replication_ means that you will have a single copy of your database. - _Single-zone replication_ means that your database will have a primary and a replica located in the same zone of a cloud region. - _Multi-zone replication_ means that the primary and its replicas are stored in different zones of a cloud region. This means that your database can remain online even if an entire zone becomes unavailable. -Your replication options depend on which subscription plan you're using: +Your replication options depend on your [subscription plan]({{}}): - _Free_ plans do not support replication. - _Fixed_ plans let you choose between no replication, single-zone replication, or multi-zone replication when creating a subscription. +- _Flexible_ and _Annual_ plans allow multi-zone or single-zone subscriptions by default. You can also disable replication. + +## Performance impact + +Replication can affect performance as traffic increases to synchronize all copies. + +Database storage costs also increase: + +- For Fixed plans, single-zone and multi-zone replication effectively doubles storage costs + +- For Flexible and Annual plans, replication requires additional shards + +## Zone setting maintenance -Zone settings cannot be changed once a subscription has been created. This means you can't convert a multi-zone subscription to a single zone (or vice-versa). +Zone settings can only be defined when a subscription is created. You cannot change these settings once the subscription becomes active. -If this becomes necessary, create a new subscription with the preferred settings and then migrate data from the original subscription.``` -- _Flexible_ plans allow multi-zone or single-zone subscriptions by default. Each type allows replication to be disabled entirely. +This means you can't convert a multi-zone subscription to a single zone (or vice-versa). - Once the subscription is created, though, you cannot switch zone settings. +To use different zone settings, create a new subscription with the preferred settings and then migrate data from the original subscription. -To learn more about Redis Enterprise Cloud subscriptions, see [Manage subscriptions]({{}}). +## More info To learn more about high availability and replication, see: - [Highly Available Redis](https://redislabs.com/redis-enterprise/technology/highly-available-redis/)