From 48a45eda50c7a8fc0e118dc4d14a3daf82146c08 Mon Sep 17 00:00:00 2001 From: Jonathan Ellis Date: Tue, 26 Jul 2016 10:54:31 -0500 Subject: [PATCH] update cassandra.yaml comments post-CASSANDRA-10243 --- conf/cassandra.yaml | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/conf/cassandra.yaml b/conf/cassandra.yaml index 7f2a6fa9d2..db4cd37632 100644 --- a/conf/cassandra.yaml +++ b/conf/cassandra.yaml @@ -656,12 +656,15 @@ cross_node_timeout: false # more than one replica on the same "rack" (which may not actually # be a physical location) # -# IF YOU CHANGE THE SNITCH AFTER DATA IS INSERTED INTO THE CLUSTER, -# YOU MUST RUN A FULL REPAIR, SINCE THE SNITCH AFFECTS WHERE REPLICAS -# ARE PLACED. -# -# IF THE RACK A REPLICA IS PLACED IN CHANGES AFTER THE REPLICA HAS BEEN -# ADDED TO A RING, THE NODE MUST BE DECOMMISSIONED AND REBOOTSTRAPPED. +# CASSANDRA WILL NOT ALLOW YOU TO SWITCH TO AN INCOMPATIBLE SNITCH +# ONCE DATA IS INSERTED INTO THE CLUSTER. This would cause data loss. +# This means that if you start with the default SimpleSnitch, which +# locates every node on "rack1" in "datacenter1", your only options +# if you need to add another datacenter are GossipingPropertyFileSnitch +# (and the older PFS). From there, if you want to migrate to an +# incompatible snitch like Ec2Snitch you can do it by adding new nodes +# under Ec2Snitch (which will locate them in a new "datacenter") and +# decommissioning the old ones. # # Out of the box, Cassandra provides # - SimpleSnitch: