| = cassandra-topologies.properties file |
| |
| The `PropertyFileSnitch` `snitch` option uses the |
| `cassandra-topologies.properties` configuration file to determine which |
| `datacenters` and racks cluster nodes belong to. If other snitches are |
| used, the xref:configuration/cass_rackdc_file.adoc[cassandra-rackdc.properties] must be used. The snitch determines |
| network topology (proximity by rack and datacenter) so that requests are |
| routed efficiently and allows the database to distribute replicas |
| evenly. |
| |
| Include every node in the cluster in the properties file, defining your |
| datacenter names as in the keyspace definition. The datacenter and rack |
| names are case-sensitive. |
| |
| The `cassandra-topologies.properties` file must be copied identically to |
| every node in the cluster. |
| |
| == Example |
| |
| This example uses three datacenters: |
| |
| [source,bash] |
| ---- |
| # 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 |
| |
| # datacenter Three |
| |
| 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 |
| ---- |
