Rank Table Configuration (Atlas A2 training product/Atlas A2 inference product)

For the Atlas A2 training product/Atlas A2 inference product, the following is an example of configuring the rank table file when there are two AI servers and each AI server has two devices:

The rank table file is in JSON format. The comments in the JSON file provided in this section are for reference only. Delete the comments when you use it.

{
    "status":"completed",  // Rank table availability flag. The value completed indicates that the rank table is available.
    "version":"1.0",       // Rank table template version. Set this option to 1.0.
    "server_count":"2",    // Number of AI servers participating in training. In this example, there are two AI servers.
    "server_list":
    [
        {
            "server_id":"node_0",  // AI server ID, which is of the string type. Ensure that the ID is globally unique.
            "device":[             // List of devices on the AI server
                {
                    "device_id":"0",            // Physical ID of the processor
                    "device_ip":"192.168.1.8",  // NIC IP address of the processor
                    "device_port":"16667",      // Listening port of the processor's NIC
                    "rank_id":"0"               // Rank ID, which starts from 0 and must be globally unique.
                },
                {
                    "device_id":"1",
                    "device_ip":"192.168.1.9", 
                    "device_port":"16667",
                    "rank_id":"1"
                }
            ]
        },
        {
            "server_id":"node_1",
            "device":[
                {
                    "device_id":"0",
                    "device_ip":"192.168.2.8",
                    "device_port":"16667",
                    "rank_id":"2"
                },
                {
                    "device_id":"1",
                    "device_ip":"192.168.2.9", 
                    "device_port":"16667",
                    "rank_id":"3"
                }
            ]
        }
    ]
}

**Table 1** Rank table file description
Level-1 Configuration Item	Level-2 Configuration Item	Level-3 Configuration Item	Description
status			Mandatory. Rank table availability flag. completed: The rank table is available. initializing: The rank table is unavailable.
version			Mandatory. Version of a rank table template. Set the value to 1.0.
server_count			Mandatory. Number of AI servers that participate in collective communication.
server_list			Mandatory. List of AI servers that participate in collective communication.
	server_id		Mandatory. AI server ID. The value is a string with a maximum of 64 characters. Ensure that the value is globally unique. Example: node_0
	device		Mandatory. List of devices on the AI server.
		device_id	Mandatory. Physical ID of the AI processor, that is, the serial number of the device on the AI server. You can run the ls /dev/davinci* command to obtain the physical ID of the AI processor. For example, /dev/davinci0 indicates that the physical ID of the AI processor is 0. The value ranges from 0 to Actual number of devices – 1. Note: device_id takes precedence over the environment variable ASCEND_DEVICE_ID.
		device_ip	Optional. IP address of the integrated NIC on the AI processor, which is globally unique and must be in the IPv4 or IPv6 format. Note: In the multi-server scenario, device_ip is required. In the single-server scenario, device_ip is optional. You can run the cat /etc/hccn.conf command on the current AI server to obtain the NIC IP address. address_0=xx.xx.xx.xx netmask_0=xx.xx.xx.xx netdetect_0=xx.xx.xx.xx address_xx shows the NIC IP address, in which xx is the physical ID of AI processor (device_id). The IP address following address_xx is the one you need to set for the device.
		device_port	Optional. Communication port of the device NIC. The value ranges from 1 to 65535. Ensure that the port is not occupied by other processes. Ports 1–1023 are reserved. Do not use these ports. Set this field for a service with one device and multiple processes. Assign each process a unique port number to avoid conflicts.
		rank_id	Mandatory. Unique ID of a rank. The value ranges from 0 to number of devices – 1. You are advised to sort rank_id based on the physical connection sequence of devices, that is, arrange devices by physical connection proximity. Otherwise, the performance may be affected. For example, if device_ip is set in ascending order based on physical connections, you are advised to set rank_id in ascending order. rank_id must be sequentially allocated within each AI server and cannot be interleaved across servers. Correct: The rank_id set is {0, 1, 2, 3} for server 1, and {4, 5, 6, 7} for server 2. Incorrect: The rank_id set is {0, 1, 2, 7} for server 1, and {3, 4, 5, 6} for server 2.

Parent topic: Cluster Configuration