From 6b8224ef8548c62f35ce4e22f01fdb355331ae62 Mon Sep 17 00:00:00 2001 From: Nadav Har'El Date: Sun, 25 Aug 2019 15:12:00 +0300 Subject: [PATCH] alternator: document choice of RF After changing the choice of RF in a previous patch, let's update the relevant part of docs/alternator.md. Signed-off-by: Nadav Har'El Message-Id: <20190825121201.31747-1-nyh@scylladb.com> --- docs/alternator.md | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/docs/alternator.md b/docs/alternator.md index b315dd59d4..d55421e8c5 100644 --- a/docs/alternator.md +++ b/docs/alternator.md @@ -34,8 +34,12 @@ of a few seconds), or you should use a different mechanism to distribute different DynamoDB requests to different Scylla nodes, to balance the load. Alternator tables are stored as Scylla tables in the "alternator" keyspace. -This keyspace is initialized when Alternator first boots, with replication -factor hard-coded to 1 (FIXME: this will need to change). +This keyspace is initialized when the first Alternator table is created +(with a CreateTable request). The replication factor (RF) for this keyspace +and all Alternator tables is chosen at that point, depending on the size of +the cluster: RF=3 is used on clusters with three or more live nodes, and +RF=1 is used for smaller clusters. Such smaller clusters are, of course, +only recommended for tests because of the risk of data loss. ## Current compatibility with DynamoDB