Support Library Service#

The Support Library Service is a critical component of the SECU4 streaming architecture, providing robust data buffering and interpolation capabilities for real-time telemetry data processing.

Overview#

The Support Library Service acts as an intermediary layer between the Stream API and data consumers, offering:

Reading
Buffering
Interpolation

Architecture#

Note: The gRPC interface for the Support Library is planned and will be implemented soon.

Support Library Architecture

Key Features#

Buffering Module#

The buffering module provides two distinct data handling approaches:

Sample Data Buffering#

Single parameter per SampleData object
Multiple samples and timestamps per parameter
Supports various data types:
- Events
- Markers
- CAN Data
- Errors

Timestamp Data Buffering#

Multiple parameters per timestamp
Unified timestamp-based processing
Same data type support as Sample Data

Interpolation Module#

The interpolation module provides:

Default statistical processing:
- First value
- Last value
- Mean
- Minimum
- Maximum
Custom processor support
Configurable processing frequencies

Configuration#

Buffering Configuration#

var bufferingConfig = new BufferingConfiguration(
    subscribedParameters: parameters,
    bufferingWindowLength: 3000,
    slidingWindowPercentage: 5,
    includeMarkerData: true,
    includeEventData: true,
    includeErrorData: true,
    includeCanData: true
);

Parameter	Description	Default
`SubscribedParameters`	List of parameters to subscribe to	null (all parameters)
`BufferingWindowLength`	Window length in milliseconds	3000 ms
`SlidingWindowPercentage`	Window sliding interval percentage	5%
`IncludeMarkerData`	Include marker data	false
`IncludeEventData`	Include event data	false
`IncludeErrorData`	Include error data	false
`IncludeCanData`	Include CAN data	false

Interpolation Configuration#

supportLibApi.InterpolationSubscribe(
    subscriptionKey: "unique-key",
    parameterIdentifiers: parameters,
    subscriptionFrequencyHz: 2,
    handler: interpolationResultHandler,
    deliveryFrequencyHz: 2
);

Parameter	Description
`SubscriptionKey`	Unique identifier for the interpolation
`ParameterIdentifiers`	List of parameters to process
`SubscriptionFrequencyHz`	Data processing frequency
`Handler`	Result handler implementation
`DeliveryFrequencyHz`	Result delivery frequency

Integration#

Stream API Integration#

var streamApiConfig = new StreamingApiConfiguration(
    StreamCreationStrategy.TopicBased,
    "localhost:9092",
    new List<string>()
);

Session Reading Configuration#

The Support Library provides robust session reading capabilities from the broker through the PacketReadingConfiguration:

var packetReadingConfig = new PacketReadingConfiguration(
    sessionIdentifierPattern: "*",  // Matches all sessions
    readingType: ReadingType.Live,
    streams: new List<string>
    {
        "Chassis"  // Example stream
    });

Parameter	Description
`SessionIdentifierPattern`	Pattern to match session identifiers (e.g., "*" for all sessions)
`ReadingType`	Type of reading (e.g., Live)
`Streams`	List of streams to read from the broker

The session reading configuration allows you to: - Filter specific sessions using pattern matching - Choose between different reading types (e.g., Live) - Select specific streams to read from - Integrate with the buffering and interpolation modules for data processing

Best Practices#

Buffering Configuration
- Adjust window length based on data rate
- Consider memory usage when including additional data types
- Monitor system performance with different sliding window percentages
Interpolation Configuration
- Match frequencies to data requirements
- Consider system resources when processing multiple parameters
- Use appropriate handlers for different data types
Error Handling
- Implement proper error logging
- Handle connection failures gracefully
- Monitor buffer overflow conditions

Example Usage#

// Initialize components
var supportLibApi = new SupportLibApiFactory().Create(
    streamApiConfig,
    packetReadingConfig,
    bufferingConfig,
    logger,
    sampleDataHandler,
    timestampDataHandler
);

// Start processing
supportLibApi.Initiate();
Task.Run(() => supportLibApi.Start());

// Subscribe to data
supportLibApi.BufferingSubscribe(subscribedParameters);
supportLibApi.InterpolationSubscribe(subscriptionKey, parameters, 2, handler, 2);

Troubleshooting#

Common issues and solutions:

High Memory Usage
- Reduce buffering window length
- Filter subscribed parameters
- Adjust sliding window percentage
Data Latency
- Check Stream API connection
- Verify buffer configuration
- Monitor system resources

Stream API Documentation