Streaming Telemetry Dial-In Mode
Overview
Dial-in mode in streaming telemetry enables collectors to initiate connections with OcNOS routers to receive operational data of interest. In this mode, the collector sends a Subscribe Remote Procedure Call (RPC) request to the gNMI server (OcNOS target device), specifying the data paths to monitor. The server then streams the requested telemetry data to the collector, facilitating proactive network monitoring and troubleshooting.
Feature Characteristics
The gNMI-based Dial-in mode telemetry for the management plane supports three types of telemetry subscriptions: Poll, Once, and Stream. It enables the "STREAM" type subscription with "SAMPLING" mode for the Subscribe RPC. The gNMI-based collector connects to the OcNOS target device and invokes the Subscribe RPC, specifying the set of path(s) of interest. Two key components are involved in this process:
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gNMI Server (OcNOS Target): The gNMI server operates within the OcNOS device, serving as the source of telemetry data. It supports the gNMI protocol, allowing gNMI-based clients (collectors) to request and receive streaming data. The server streams the requested data to the client according to the specified parameters. |
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gNMI Client (Collector): The gNMI client, also known as the collector, runs outside the OcNOS target device and is responsible for receiving and gathering telemetry data. In this context, it is the entity that connects to the OcNOS target device to collect data using the gNMI protocol. The collector initiates the Subscribe RPC to specify the data of interest. |
Figure 5 illustrates the gNMI client's (Collector) Subscribe request and response (RPC) interaction with the gNMI server (OcNOS Target).
Figure 5. Sample Subscribe Request
Example Message Flow: Subscribe Request and Response
Figure 6 illustrates a sample gnmic Subscribe Request and Subscribe Response between the collector and the OcNOS target device.
Step 1: Subscription Request Initiation
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The gnmic collector server initiates a Subscribe Request by sending a Subscribe RPC in Stream type. |
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This subscription request aims explicitly to gather data related to interface state counters and CPU state. |
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A fixed 30/45-second sampling interval is set for data collection. |
Step 2: Data Collection and Processing
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The gNMI server, within the OcNOS router, is responsible for data collection. |
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At regular 30/45-second intervals, it retrieves data from the sensor path, focusing on interface state counters and CPU State. |
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The received data undergoes a validation process, and the data is transformed into the required encoding type. |
Step 3: Continuous Subscription Response Streaming
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The gNMI Server responds to the subscription request by continuously streaming Subscribe Response data. |
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This streaming process maintains the same 30/45-second interval as the data collection. |
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The collected data is streamed in real-time to the gnmic collector server. |
Figure 6. Message Flow: Subscribe Request and Response
Benefits
Proactive Network Monitoring: Obtain real-time insights into network health and performance, and how to enable quicker response to issues.
Resource Utilization Monitoring: Monitor CPU and memory utilization to optimize resource allocation and performance.
Predictive Troubleshooting: Identify patterns and potential issues before they impact the network, reducing downtime.
Automation and Resilience: Use telemetry data to automate network management tasks and design a more resilient network.
Prerequisites
Before configuring Dial-In mode, ensure that:
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A supported OcNOS router running a compatible release. |
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Access to the management interface of the router. |
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Any gNMI client that complies with gNMI specifications can be used as a client. |
