Add tips/directions for prod setups with cadence-cassandra-tool (cade…

…nce-workflow#788)

* Add tips/directions for prod setups with cadence-cassandra-tool

* Add link to cassandra consistency calculator

tools/cassandra/README.md

@@ -10,6 +10,15 @@ This package contains the tooling for cadence cassandra operations.
 make install-schema
 ```
 
+## Setting up schema for production use
+The default Makefile sets up a replication factor of 1.  This should be used for developer setups when running Cadence server on a laptop. For production clusters we recommend to use a replication factor of 3. Please use 'cadence-cassandra-tool' to create both the cadence and cadence_visibility keyspaces. It already has an option to configure the replication factor.
+
+```
+cadence-cassandra-tool --ep $CASSANDRA_SEEDS create -k $KEYSPACE --rf $RF
+```
+
+See https://www.ecyrd.com/cassandracalculator for an easy way to determine how many nodes and what replication factor you will want to use.  Note that Cadence by default uses `Quorum` for read and write consistency.
+
 ## Setting up schema on a new cluster manually
 ```
 ./cadence-cassandra-tool -ep 127.0.0.1 -k cadence setup-schema -v 0.0 -- this sets up just the schema version tables with initial version of 0.0
@@ -28,4 +37,5 @@ You can only upgrade to a new version after the initial setup done above.
 
 ./cadence-cassandra-tool -ep 127.0.0.1 -k cadence_visibility update-schema -d ./schema/visibility/versioned -v x.x -y -- executes a dryrun of upgrade to version x.x
 ./cadence-cassandra-tool -ep 127.0.0.1 -k cadence_visibility update-schema -d ./schema/visibility/versioned -v x.x    -- actually executes the upgrade to version x.x
-```
+```
+