Config File Definitions

Definitions describe config files that LCM needs to generate configs for the target nodes. The LCM UI uses these to generate forms, but an API consumer can use them to know what the valid properties are for each config file. As with most of the LCM API, definitions are discoverable. The running API can be navigated by going to /api/v1/lcm/definitions/.

Routes

GET /api/v1/lcm/definitions/

Gets a list of all of the DSE versions supported by OpsCenter and LCM, with links to the definitions for each version.

Example

curl http://localhost:8888/api/v1/lcm/definitions/

Output:

{
    "dse": [
        {
            "version": "4.7.0",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.7.0/"
        },
        {
            "version": "4.7.1",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.7.1/"
        },
        {
            "version": "4.7.2",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.7.2/"
        },
        {
            "version": "4.7.3",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.7.3/"
        },
        {
            "version": "4.7.4",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.7.4/"
        },
        {
            "version": "4.7.5",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.7.5/"
        },
        {
            "version": "4.7.6",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.7.6/"
        },
        {
            "version": "4.7.7",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.7.7/"
        },
        {
            "version": "4.7.8",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.7.8/"
        },
        {
            "version": "4.8.0",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.8.0/"
        },
        {
            "version": "4.8.1",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.8.1/"
        },
        {
            "version": "4.8.2",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.8.2/"
        },
        {
            "version": "4.8.3",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.8.3/"
        },
        {
            "version": "4.8.4",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.8.4/"
        },
        {
            "version": "4.8.5",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.8.5/"
        },
        {
            "version": "4.8.6",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.8.6/"
        },
        {
            "version": "4.8.7",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.8.7/"
        },
        {
            "version": "4.8.8",
            "href": "http://localhost:8888/api/v1/lcm/definitions/4.8.8/"
        },
        {
            "version": "5.0.0",
            "href": "http://localhost:8888/api/v1/lcm/definitions/5.0.0/"
        }
    ]

}

GET /api/v1/lcm/definitions/{version}/

Gets the definitions for a specific version of DSE.

At the top level are file-id keys. These loosely look like the filename, when there is an actual distinctive filename. Examples: cassandra-yaml for /etc/dse/cassandra/cassandra.yaml.

There are a number of properties you may notice missing from cassandra-yaml - these are node-specific properties like listen_address and rpc_address, and should be configured via the fields on Node.

The value for each definitions key is an object with the following attributes:

renderer

Used internally by LCM to generate the output for the config file.

display-name

Used by LCM UI.

groupings

Used by LCM UI.

properties

Each key represents the name of a config file property. Some properties are simple scalar values, but they can also be nested objects or lists. See Property Fields below for more info.

Example:

curl http://localhost:8888/api/v1/lcm/definitions/4.8.6/

Output:

Go to the actual endpoint on your OpsCenter machine in a browser (we recommend using a JSON viewer plugin for easy reading). A single definitions response can be rather large, and is subject to change during operation when OpsCenter automatically downloads updated definitions.

Property Fields

When using definitions as a reference for building a Config Profile it will be important to understand the different types of properties, and how they translate into a config structure. Note that much of the property meta-data is related to the LCM UI. Here we will only cover the attributes that are important for generating properly formed config profiles.

Default Values

When the field has a default_value, that value will be rendered in the config file by LCM automatically. You do not need to include such values in your config profile unless you intend to override the default.

Scalar Types

The simplest properties are scalar values (int, float, string, etc)

Type	JSON
int	{"property": 14}
float	{"property": 0.1
string	{"property": "value"}
boolean	{"property": true}

Dict Type

Nested properties are defined as property type dict. In this case the value will be a JSON object. All dict type properties will have a fields attribute defining the object keys and what types their values are. This is best show with an example:

Property Definition

{
    "request_scheduler_options": {

        "conditional": [
            {
                "eq": "org.apache.cassandra.scheduler.RoundRobinScheduler"
            }
        ],
        "depends": "request_scheduler",
        "type": "dict",
        "required": false,
        "fields": {
            "default_weight": {
                "default_value": 5,
                "type": "int",
                "required": true
            },
            "throttle_limit": {
                "default_value": 80,
                "type": "int",
                "required": true,
                "unit": "requests"
            }
        }
    }
}

Sample Profile

{
    "datastax-version":"5.0.0",
    "name":"dev",
    "comment":"development profile",
    "json":{
        "cassandra-yaml":{
            "request_scheduler_options":{
                "default_weight":6,
                "throttle_limit": 90
            }
        }
    }
}

List Type

Some config file property values are lists. A list type definition will have a value_type attribute, indicating the type of the values in the list. The value_type could be any of the valid property types defined in this document.

Property Definition

{
    "data_file_directories": {

        "value_type": "string",
        "default_value": [
            "/var/lib/cassandra/data"
        ],
        "type": "list",
        "required": true
    }
}

Sample Profile

{
    "datastax-version":"5.0.0",
    "name":"dev",
    "comment":"development profile",
    "json":{
        "cassandra-yaml":{
             "data_file_directories": ["/mnt/data1","/mnt/data2"]
        }
    }
}

User-defined Type

A user_defined type is almost the same as a dict type (the value is an object), but the keys are defined by the user.

Property Definition

{
    "request_scheduler_options": {
        "conditional": [
            {
                "eq": "org.apache.cassandra.scheduler.RoundRobinScheduler"
            }
        ],
        "depends": "request_scheduler",
        "type": "dict",
        "required": false,
        "fields": {
            "weights": {
                "value_type": "int",
                "type": "user_defined",
                "required": false,
                "key_name": "keyspace"
            }
        }
    }
}

Sample Profile

{
    "datastax-version":"5.0.0",
    "name":"dev",
    "comment":"development profile",
    "json":{
        "cassandra-yaml":{
            "request_scheduler_options":{
                "keyspace_1": 1,
                "keyspace_2": 1
            }
        }
    }
}