Version Information
Release Notes, Update information, Certifications and Frequently Asked Questions.
Concepts
Your first step into modern and powerful process visualization.
Deployment
Topics, you need to know, before using WinCC OA.
Security
Go beyond the norm in cybersecurity.
Engineering
Powerful tools for easy or complex engineering tasks.
Data Management
Classify, structure and archive your data.
Business Logic / Control
Endless possibilities in data processing for your projects.
Data Visualization
User interfaces, Trends and Reports for every purpose and device.
Southbound Interfaces
The process connection to the actual machines/sensors.
Northbound Interfaces
Your portal to the cloud or supervising systems.
Web Connectivity / Network Interfaces
Data exchange, APIs and web technologies
User Management
All about authorization, authentication and login-customization.
Availability
How to get your system uptime to the maximum.
- Redundancy
  The high availability requirements of plant constructors and operators as well as the process and data security can be covered with the redundancy concept of WinCC OA.
- Redundant network connections
  In order to achieve a better fault tolerance WinCC OA Managers can connect to other WinCC OA Managers running on different computers via redundant network connections (this means connecting through two network connections (= IP connection)).
- Alive mechanism of manager connections
  The alive mechanism in WinCC OA serves for connection controlling between the single managers. Each manager sends alive messages at definable intervals.
- Error tolerance and stability
  Continuous improvements are made concerning the error tolerance and reliability. This page gives an overview and description of the changes. Additional information can be found in the further chapters of the documentation.
- Kubernetes Health Check
  An introduction to health checks with Kubernetes for WinCC OA.
- Message Compression
  The message compression compresses WinCC OA messages. Data compression means encoding information using fewer bits than an unencoded representation would use through use of specific encoding schemes.
- Identification Caching
  The identification caching provides you an advantage especially when using remote user interfaces and distributed systems. Identification caching allows the identification to be sent as “delta” instead of the whole identification. Thus, only the changes are sent by the Data and the Dist managers.
Reporting
Create state of the art project reports without limits.
Addons
Useful tools and enhancements for special demands.
Reference Tables
Detailed and extensive content for special project adaptation.
Videos & Tutorials
Explore the capabilities of WinCC OA with our carefully selected collection of video tutorials and guides.
WinCC OA Documentation
Basic information about terms and functions within the documentation.
Disclaimer
A brief clarification of liability exclusions or legal notices.

Kubernetes Health Check

An introduction to health checks with Kubernetes for WinCC OA.

Overview

A health check queries the status of running managers. A health check command is used during startup of a container. If the container is "healthy", the health check returns 0. The health check is meaningful since when a docker container is "healthy", you can interact with it and do not need to wait any longer. A Health check can be added to the end of a dockerfile as follows:

HEALTHCHECK --interval=5s --timeout=5s --start-period=10s --retries=20 CMD "${BIN_DIR}
WCCILpmon" -config ${OAPROJ}config/config -status || exit 1

You can find a health probe example for OA running in Docker (or Kubernetes). The files are located in wincc_oa_path/data/containerization/examples/kubernetes/healthProbes.

How does the Health Check work with WinCC OA

To enable Kubernetes to monitor the health status of WinCC OA components/containers, you can use the provided

liveness.sh script

Kubernetes executes liveness.sh directly within the container to perform a liveness test.

The test is realized internally by executing the following command in the directory $OAINST/bin/:

WCCILpmon -config $OAPROJ/config/config -command MGRLIST:STATI -log +stdout

Please make sure that the environment variables $OAINST and $OAPROJ_NAME are set in your containers, or adapt the script to your specific needs. The following logic is then used to evaluate the health state of the WinCC OA runtime:

Figure 1. Logic to evaluate the Health State

Standby and startup tests can be disabled (or implemented according to your own requirements). The startup tests are not required as we do not expect inconsistent startup times of the WinCC OA runtime. Below you can find a configuration example:

Figure 2. Configuration Example

Note: For larger projects, the values may not be sufficient and should be adapted to your needs.

When adjusting the values, note that Kubernetes uses the values in the following order:

Wait for initialDelaySeconds
Perform readiness check and wait timeoutSeconds for a timeout
If the number of continued successes is greater than successThreshold, return success

Or

If the number of continued failures is greater than failureThreshold, failure is returned

otherwise wait periodSeconds and start a new readiness check.