Creating a fault group input file

Use a text editor to create a fault group input file for the targeted cluster.

The following example shows how you can create a fault group input file for a cluster that has 8 racks with 8 nodes on each rack—for a total of 64 nodes in the cluster.

On the first line of the file, list the parent (top-level) fault groups, delimited by spaces.
```
rack1 rack2 rack3 rack4 rack5 rack6 rack7 rack8
```

On the subsequent lines, list the parent fault group followed by an equals sign (=). After the equals sign, list the nodes or fault groups delimited by spaces.

<parent> = <child_1> <child_2> <child_n...>

Such as:

rack1 = v_vmart_node0001 v_vmart_node0002 v_vmart_node0003 v_vmart_node0004
rack2 = v_vmart_node0005 v_vmart_node0006 v_vmart_node0007 v_vmart_node0008
rack3 = v_vmart_node0009 v_vmart_node0010 v_vmart_node0011 v_vmart_node0012
rack4 = v_vmart_node0013 v_vmart_node0014 v_vmart_node0015 v_vmart_node0016
rack5 = v_vmart_node0017 v_vmart_node0018 v_vmart_node0019 v_vmart_node0020
rack6 = v_vmart_node0021 v_vmart_node0022 v_vmart_node0023 v_vmart_node0024
rack7 = v_vmart_node0025 v_vmart_node0026 v_vmart_node0027 v_vmart_node0028
rack8 = v_vmart_node0029 v_vmart_node0030 v_vmart_node0031 v_vmart_node0032

After the first row of parent fault groups, the order in which you write the group descriptions does not matter. All fault groups that you define in this file must refer back to a parent fault group. You can indicate the parent group directly or by specifying the child of a fault group that is the child of a parent fault group.

Such as:

rack1 rack2 rack3 rack4 rack5 rack6 rack7 rack8
rack1 = v_vmart_node0001 v_vmart_node0002 v_vmart_node0003 v_vmart_node0004
rack2 = v_vmart_node0005 v_vmart_node0006 v_vmart_node0007 v_vmart_node0008
rack3 = v_vmart_node0009 v_vmart_node0010 v_vmart_node0011 v_vmart_node0012
rack4 = v_vmart_node0013 v_vmart_node0014 v_vmart_node0015 v_vmart_node0016
rack5 = v_vmart_node0017 v_vmart_node0018 v_vmart_node0019 v_vmart_node0020
rack6 = v_vmart_node0021 v_vmart_node0022 v_vmart_node0023 v_vmart_node0024
rack7 = v_vmart_node0025 v_vmart_node0026 v_vmart_node0027 v_vmart_node0028
rack8 = v_vmart_node0029 v_vmart_node0030 v_vmart_node0031 v_vmart_node0032

After you create your fault group input file, you are ready to run the fault_group_ddl_generator.py. This script generates the DDL statements you need to create fault groups in Vertica.

If your Vertica database is co-located on a Hadoop cluster, and that cluster uses more than one rack, you can use fault groups to improve performance. See Configuring rack locality.

Creating a fault group input file

See also