Overview


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1. What is Kiali?

Kiali provides answers to the questions: What are the microservices in my Istio service mesh, and how are they connected?

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Figure 1. Kiali Graph

 
A Microservice Architecture breaks up the monolith into many smaller pieces that are composed together. Patterns to secure the communication between services like fault tolerance (via timeout, retry, circuit breaking, etc.) have come up as well as distributed tracing to be able to see where calls are going.

A service mesh can now provide these services on a platform level and frees the application writers from those tasks. Routing decisions are done at the mesh level.

Kiali works with Istio, in OpenShift or Kubernetes, to visualize the service mesh topology, to provide visibility into features like circuit breakers, request rates and more. It offers insights about the mesh components at different levels, from abstract Applications to Services and Workloads.

     Kiali also includes Jaeger Tracing to provide distributed tracing out of the box.

2. What does it do?

2.1. Graph View

Kiali provides an interactive graph view of your namespace in real time, being able to display the interactions at several levels (applications, versions, workloads), with contextual information and charts on the selected graph node or edge.

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Figure 2. Kiali Graph

 

2.2. Applications

The Applications menu entry shows all the applications running in our environment.

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Figure 3. List of Applications

 
Kiali provides detailed information related to the application, such as its health or the list of its workloads. The health summary comes with detailed information of multiple indicators in a tooltip.  

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Figure 4. Application Info

 
Kiali also displays Istio metrics associated with an application.  

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Figure 5. Application Metrics

 

2.3. Workloads

The Workloads menu entry shows the list of workloads with their health, error rate and labels validations.  

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Figure 6. List of Workloads

 
By selecting a workload, the related information is displayed along with the associated pods and services.  

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Figure 7. Workload Info

 

2.4. Services

The Services menu entry shows the list of services with their health and error rate.

When selecting a single service, its details page includes service ip, ports, endpoints, workloads, destination rules, virtual services and more details.

Inbound/outbound metrics are displayed for this service and a more detailed view is available in a linked Grafana dashboard.

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Figure 8. Service Info

 

2.5. Istio Config

The Istio Config menu entry displays a list of all of the available Istio configuration objects that exist in the user’s environment.

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Figure 9. List of Istio Configs

 
You can inspect the configuration yaml around a specific Istio object.  

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Figure 10. Valid Configuration of Istio Config

 
Kiali will highlight configuration errors.  

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Figure 11. Invalid Configuration of Istio Config

 

2.5.1. Validations performed

This section lists all the validations that Kiali performs on all Istio configurations. Most of these validations are done in addition to/on top of the existing ones performed by Istio’s Galley component (except those marked as deprecated)

Table 1. List of destination rule validations
Validation message Severity Description Source Example

More than one Destination Rules for same host subset combination

warning

Warning shown when 2 Destination Rules points to the same host and shares one or more subsets

source code

001.yaml

Host doesn’t have a valid service

error

When one destination rule has a host that doesn’t exist

source code

002.yaml

Table 2. List of virtual service validations
Validation message Severity Description Source Example

VirtualService is pointing to a non-existent gateway

error

When the virtual service has a specified a gateway that doesn’t exist

source code

101.yaml

DestinationWeight on route doesn’t have a valid service (host not found)

error

When a destination weight has a host that doesn’t exist

source code

102.yaml

VirtualService doesn’t define any route protocol

error

When a Virtual Service doesn’t define neither tcp, http, tls routes

source code

103.yaml

More than one Virtual Service for same host

warning

When two virtual services points to same host

source code

104.yaml

Subset not found

warning

When there is no subset defined in any destination rule

source code

105.yaml

Destination field is mandatory

error

When a Destination field within a DestinationWeight is empty

source code

106.yaml

(Deprecated) Weight must be a number

error

When a destination weight is not a number

source code

107.yaml

(Deprecated) Weight should be between 0 and 100

error

When a destination weight is > 100 or < 0

source code

108.yaml

(Deprecated) Weight sum should be 100

error

When the sum of all the weight for a protocol doesnt sum 100

source code

109.yaml

(Deprecated) All routes should have weight

error

When one destinationWeight has no weight, but all the rest have

source code

110.yaml

Table 3. List of Gateway validations
Validation message Severity Description Source Example

More than one Gateway for the same host port combination

warning

When two or more gateways (from same or different namespace) point to the same host-port combination

source code

201.yaml

2.6. Distributed Tracing

Clicking on Distributed Tracing menu item will open a new tab with the Jaeger UI for tracing services.