The Context Guide is a visual representation of Application Perspective services and related underlying infrastructure. Behind the scenes it is driven by Instana's powerful Dynamic Graph--a core component of Instana in which all the physical components of your infrastructure are tracked and associated with their logical counterparts and automatically kept up-to-date when changes occur.
The Dynamic Graph is a core concept underpinning the Context Guide and is discussed in detail here
The visualization of the Dynamic Graph is done through the Stack button. The Stack lists the various Application Perspective services and infrastructure linked to those services. The Kubernetes tab of the Context Guide will list Kubernetes resources like Cluster, Deployment and Pod. The Context Guide Infrastructure tab will list physical infrastructure like Host, Process, Docker Container, Java Virtual Machine or others.
One of the key features of the Context Guide is the way in which infrastructure is grouped by the high-level type in which an item might logically be expected to fall. For example, Clusters and Containers are visually represented in distinct sections within the Context Guide. Grouping items by their high-level types is particularly useful in presenting an overview of the various components in your infrastructure at a glance.
To illustrate the power of showing the context of a particular infrastructure component, open the Context Guide Stack for a Kubernetes Namespace. The cluster in which this namespace resides is listed, as are the the nodes on which are scheduled pods of deployments in this namespace. Putting these various pieces of your infrastructure together into the Stack is a powerful way to quickly navigate between components related to one another.
The Upstream information is helpful to identify the impacted services and applications when the current entity is experiencing issues like high latency or errors. The Upstream tab shows services and application that the current entity is directly called by. Calls from upstream services that are not monitored by Instana will be grouped under "Not Monitored By Instana".
The Downstream information is helpful for finding out what services and applications the current entity depends on that are experiencing similar issues and may be the root cause. The Downstream tab shows services and applications that the current entity is directly calling.
The Upstream and the Downstream information are always based on all calls of a given application perspective no matter what its default or currently selected application scope is.