The Grafana data source plugin for Instana is designed to query and retrieve metric data directly from the Instana backend. This communication is facilitated through the Instana Web REST API. By definition, a REST (Representational State Transfer) API operates over the HTTP (Hypertext Transfer Protocol) or HTTPS protocol. The Grafana plugin acts as an HTTP client, sending requests to the Instana API endpoints to fetch the necessary data for visualization in Grafana dashboards.

A. gRPC: This is a high-performance RPC framework. The Instana Web REST API, which the Grafana plugin uses, is based on HTTP, not gRPC.

B. SOP: Same-Origin Policy is a web browser security mechanism that restricts cross-origin HTTP requests, not a protocol for fetching data.

D. JDBC: Java Database Connectivity (JDBC) is an API for connecting Java applications to databases. The Grafana plugin connects to the Instana application API, not directly to a database via JDBC.

1. IBM Documentation - Grafana plugin: "The Instana data source plugin for Grafana uses our Web REST API to fetch infrastructure metrics from Instana and to make them available in your Grafana dashboards." (Source: IBM Documentation, Instana Observability, Section: Integrating > Dashboards > Grafana plugin).

2. IBM Documentation - Web REST API: This section details the various HTTP-based endpoints available for interacting with Instana, which is the foundation for the Grafana plugin's data retrieval mechanism. (Source: IBM Documentation, Instana Observability, Section: Developing > Web REST API).

The recommended and most robust method for installing the Instana host agent on Kubernetes is by using the Instana Agent Operator. The Operator is a Kubernetes-native application that automates the deployment and lifecycle management of the agent. It simplifies installation, configuration, and updates by managing the agent DaemonSet across all schedulable nodes in the cluster. This approach aligns with best practices for managing applications on Kubernetes, providing a declarative and automated way to ensure the agent is always running and correctly configured.

A. Homebrew: This is a package manager for macOS and Linux, designed for installing software on a single workstation, not for deploying agents across a Kubernetes cluster.

B. Binary: While the agent is a binary, this is not a valid installation method for Kubernetes. A direct binary installation is impractical for managing deployments on a multi-node, dynamic cluster.

D. RPM: This is a package management system for Red Hat-based Linux distributions. It is used for single-host installations and is not the standard method for deploying applications on Kubernetes.

1. IBM Instana Observability Documentation: "Installing the Instana agent on Kubernetes". This official documentation explicitly lists the Operator as the recommended installation method. It states, "The recommended way to install the Instana agent on Kubernetes is by using the Instana Agent Operator." The page details the steps for deploying the agent using the Operator, Helm Chart, or a YAML file (DaemonSet), with the Operator being the primary recommendation.

Source: IBM Documentation, Instana Observability, "Installing the Instana agent on Kubernetes".

2. IBM Instana Observability Documentation: "Host agent installation". This page provides an overview of installation methods for various platforms. For Kubernetes, it directs users to the specific Kubernetes installation guide, which prioritizes the Operator method. The sections for other operating systems like Linux detail the use of package managers (like RPM and DEB), clearly distinguishing them from the Kubernetes approach.

Source: IBM Documentation, Instana Observability, "Host agent installation".

The Infrastructure map in IBM Instana provides a dynamic and interactive visualization of all monitored systems. Its primary purpose is to offer a high-level overview of the entire infrastructure landscape. A key organizational feature of this map is the grouping of systems by availability zones, which helps in understanding the physical or logical layout and health of the infrastructure at a glance. Users can interact with the map by zooming, panning, and selecting specific hosts or zones to investigate further details and metrics.

A. This is partially correct but incomplete. The map does show relations, but its defining feature is the overview of all systems grouped by zones, which this option omits.

B. The map is dynamic and interactive, reflecting real-time data. A static image would not serve the purpose of live infrastructure monitoring, making this option incorrect.

D. This describes the Application Perspective or Dependency Map, which visualizes the relationships and calls between services, not the underlying infrastructure hosts and zones.

1. IBM Instana Observability Documentation, "Visualizing infrastructure": "The Infrastructure map provides an overview of all monitored systems. It helps you to understand the layout of your system and provides a high-level overview of your infrastructure... The map is organized by zones... The map is interactive. You can zoom, pan, and click on individual systems to see more details." (IBM Documentation, Visualizing infrastructure, Infrastructure map section).

Instana enforces a default rate limit on its Web REST API to ensure service stability and fair usage across all tenants. This limit is set at 5,000 calls per hour for each individual API token. When an API call is made, Instana checks the usage associated with the token provided in the Authorization header. If the number of calls exceeds this limit within the hour, subsequent requests will be rejected with an HTTP 429 Too Many Requests status code until the rate limit window resets.

A. 10,000: This value is incorrect; the default hourly limit is half of this amount.

C. 6,000: This is not the specified default rate limit in the official Instana documentation.

D. 1,000: This value is significantly lower than the actual default limit of 5,000 calls per hour.

1. IBM Documentation for Instana Observability. "Web REST API". Section: Rate Limiting. The documentation states, "The rate limit for API calls is 5000 calls per hour per API token." This is the primary source defining the default value.

The X-Instana-Service is a specific HTTP header that Instana sensors are pre-configured to automatically recognize and process. If this header is present in an incoming request, its value is used to name the service for that particular transaction, overriding any other service naming configurations. This mechanism allows for dynamic service naming on a per-request basis. The collection and use of this header are a built-in, automatic feature of the Instana instrumentation and do not require additional custom configuration in the agent.

A. x-client-id: This is an example of a generic custom header. Instana does not collect arbitrary HTTP headers by default and requires explicit configuration to capture them.

B. Instana-probe: This is not a standard, documented Instana header that is automatically collected for general tracing or service monitoring purposes.

C. Instana-id: This is not a standard Instana header. Trace context, including trace and span IDs, is propagated via the X-INSTANA-T and X-INSTANA-S headers.

1. IBM Documentation, Instana Observability on SaaS, "Naming services": This document explicitly states, "You can set a service name for a specific request by using the X-Instana-Service HTTP header. When you set the header on a request, it will take precedence over all other service naming configurations." This confirms the header is automatically processed for service naming.

2. IBM Documentation, Instana Observability on SaaS, "Monitoring custom HTTP headers": This source clarifies the default behavior for other headers: "By default, Instana does not collect HTTP headers as it can contain sensitive data. However, the feature can be enabled on-demand..." This directly contrasts with the automatic handling of X-Instana-Service and shows why option A is incorrect.