PropertyFileSnitch
Determines the location of nodes by rack and datacenter.
This snitch determines proximity as determined by rack and datacenter. It uses the network details located in the cassandra-topology.properties file. When using this snitch, you can define your datacenter names to be whatever you want. Make sure that the datacenter names correlate to the name of your datacenters in the keyspace definition. Every node in the cluster should be described in the cassandra-topology.properties file, and this file should be exactly the same on every node in the cluster.
The location of the
cassandra-topology.properties file depends on the type of installation:
| Cassandra package installations | /etc/cassandra/cassandra-topology.properties |
| Cassandra tarball installations | install_location/conf/cassandra-topology.properties |
Procedure
If you had non-uniform IPs and two physical datacenters with two racks in
each, and a third logical datacenter for replicating analytics data, the
cassandra-topology.properties file might look like
this:
Note: datacenter and rack names are
case-sensitive.
# datacenter One
175.56.12.105=DC1:RAC1
175.50.13.200=DC1:RAC1
175.54.35.197=DC1:RAC1
120.53.24.101=DC1:RAC2
120.55.16.200=DC1:RAC2
120.57.102.103=DC1:RAC2
# datacenter Two
110.56.12.120=DC2:RAC1
110.50.13.201=DC2:RAC1
110.54.35.184=DC2:RAC1
50.33.23.120=DC2:RAC2
50.45.14.220=DC2:RAC2
50.17.10.203=DC2:RAC2
# Analytics Replication Group
172.106.12.120=DC3:RAC1
172.106.12.121=DC3:RAC1
172.106.12.122=DC3:RAC1
# default for unknown nodes
default =DC3:RAC1