App Record and Replay - Getting Started

Overview

When using the App Record and Replay service the following EdgeX services are required to be running:

1. Source device service(s). These are the device service(s) generating the events that will be recorded.
   • This guide uses Device Virtual as the source device service. In a real use case the source device service(s) will be connected to actual devices.
2. Core EdgeX services
3. Application or Supporting service that will process the Events
   • This guide uses the standard App Rules Engine as the app service which is processing the events.

Running Services

The simplest way to run all the required services is to use the Compose Builder tool from a terminal window

1. Clone https://github.com/edgexfoundry/edgex-compose/tree/main

2. Change to the compose-builder folder

3. Run the services

   make run no-secty ds-virtual as-record-replay
   

This runs, in non-secure mode, all the standard EdgeX services along with the Device Virtual and App Record Replay services. App Rules Engine is part of the standard services and is used in this guide for processing the events.

Postman

A sample Postman collection is provided to simplify controlling this service via its REST API. See the Postman Collection section for more details.

Debug Logging

Optionally, the debug logging can be enabled on the App Record Replay service. This is accomplished by setting LogLevel value via the Consul UI at http://localhost:8500/ui/dc1/kv/edgex/v3/app-record-replay/Writable/LogLevel/edit to DEBUG

App service debug logging is very verbose, so when viewing the logs for this service, it is useful to filter the log messages for those that start with "ARR ". If you are using Portainer to view the service logs, simply place the "ARR " text in the search text box.

To see that the replayed events are being "processed" we also need to enable debug logging for App Rules Engine. Set the LogLevel value via the Consul UI at http://localhost:8500/ui/dc1/kv/edgex/v3/app-rules-engine/Writable/LogLevel/edit to DEBUG

For App Rules Engine we want to filter for messages showing the events received. Filtering the log messages for "match the incoming topic" text will accomplish this.

Recording a Session

Start a Recording

Before starting a recording session first review the Start Recording POST API in the API Reference section. Be sure to view both examples.

The source device service(s) need to be producing events prior to or shortly after the recording is starting. In this guide, Device Virtual is already producing events. So all that is need is to start the recording session by using the Start Recording request from the Postman collection referenced above. Edit the RecordRequest to set the duration and/or eventLimit and optionally any of the filters. The existing example filters can be removed so that all events are recorded.

After above is completed simply press Send in Postman to start the recording session .

level=DEBUG ts=2023-10-02T18:21:36.311518009Z app=app-record-replay source=manager.go:116 msg="ARR Start Recording: Filter for profile names [Random-Integer-Device Random-Float-Device Random-UnsignedInteger-Device] function added to the functions pipeline"
level=DEBUG ts=2023-10-02T18:21:36.311552809Z app=app-record-replay source=manager.go:122 msg="ARR Start Recording: Filter out profile names [Random-Binary-Device Random-Boolean-Device] function added to the functions pipeline"
level=DEBUG ts=2023-10-02T18:21:36.311561009Z app=app-record-replay source=manager.go:128 msg="ARR Start Recording: Filter for device names [Random-Float-Device Random-Integer-Device Random-UnsignedInteger-Device] function added to the functions pipeline"
level=DEBUG ts=2023-10-02T18:21:36.311565609Z app=app-record-replay source=manager.go:134 msg="ARR Start Recording: Filter out device names [Random-Binary-Device Random-Boolean-Device] function added to the functions pipeline"
level=DEBUG ts=2023-10-02T18:21:36.311570208Z app=app-record-replay source=manager.go:140 msg="ARR Start Recording: Filter for source names [UInt8 Int8 Float32] function added to the functions pipeline"
level=DEBUG ts=2023-10-02T18:21:36.311574708Z app=app-record-replay source=manager.go:146 msg="ARR Start Recording: Filter out source names [UInt16 Int16 Float64] function added to the functions pipeline"
level=DEBUG ts=2023-10-02T18:21:36.311581508Z app=app-record-replay source=manager.go:170 msg="ARR Start Recording: CountEvents, Batch and ProcessBatchedData functions added to the functions pipeline"
level=DEBUG ts=2023-10-02T18:21:36.311655007Z app=app-record-replay source=manager.go:181 msg="ARR Start Recording: Recording of Events has started with EventLimit=10 and Duration=1m0s"
level=DEBUG ts=2023-10-02T18:21:42.25263302Z app=app-record-replay source=manager.go:651 msg="ARR Event Count: received event to be recorded. Current event count is 1"
level=DEBUG ts=2023-10-02T18:21:42.329114999Z app=app-record-replay source=manager.go:651 msg="ARR Event Count: received event to be recorded. Current event count is 2"
level=DEBUG ts=2023-10-02T18:21:57.336936895Z app=app-record-replay source=manager.go:651 msg="ARR Event Count: received event to be recorded. Current event count is 3"
level=DEBUG ts=2023-10-02T18:22:12.253729459Z app=app-record-replay source=manager.go:651 msg="ARR Event Count: received event to be recorded. Current event count is 4"
level=DEBUG ts=2023-10-02T18:22:12.335495342Z app=app-record-replay source=manager.go:651 msg="ARR Event Count: received event to be recorded. Current event count is 5"
level=DEBUG ts=2023-10-02T18:22:27.337831668Z app=app-record-replay source=manager.go:651 msg="ARR Event Count: received event to be recorded. Current event count is 6"
level=DEBUG ts=2023-10-02T18:22:42.254128347Z app=app-record-replay source=manager.go:673 msg="ARR Process Recorded Data: Recording of Events has ended and functions pipeline has been removed"
level=DEBUG ts=2023-10-02T18:22:42.254513348Z app=app-record-replay source=manager.go:696 msg="ARR Process Recorded Data: 6 events in 1m5.942835741s have been saved for replay"

Check Recording Status

The status of a recording session can be checked while it is running or after is has completed. Review the Recording Status GET API in the API Reference section and use the Recording Status request from the Postman collection referenced above. Press Send in Postman to get the recording status.

Recording currently running response:
{
    "inProgress": true,
    "eventCount": 1,
    "duration": 10057080770
}

Recording completed response:
{
    "inProgress": false,
    "eventCount": 6,
    "duration": 65942835741
}

Cancel Recording

A recording session can be canceled while it is running. Review the Cancel Recording DELETE API in the API Reference section and use the Cancel Recording request from the Postman collection referenced above. Press Send in Postman to cancel the recording session.

Replaying a Session

Start Replay

To start a replay session first review the Start Replay POST API in the API Reference section and then use the Start Replay request from the Postman collection referenced above.

Set the replayRate to desired value. Value must be greater than zero. Values less than 1 replay slower and values greater than 1 replay faster than originally recorded. Value of 1 replays at the originally recorded rate.

Optionally set the repeatCount which determines how many times to replay the recorded session. Defaults to once if not set or set to 0.

The source device services should be stopped from producing any new events prior to starting the replay session. In a real use case where the devices are no longer available, the device service(s) would not have any actual devices connected to generate events. In this guide we simply stop the Device Virtual container, which can be done from Portainer or with a docker CLI command.

docker stop edgex-device-virtual

After above is completed simply press Send in Postman to start the replay session .

Check Replay Status

The status of a replay session can be checked while it is running or after is has completed. Review the Replay Status GET API in the API Reference.md section and use the Replay Status request from the Postman collection referenced above. Press Send in Postman to get the replay status.

Replay currently running response:
{
    "running": true,
    "eventCount": 5,
    "duration": 2773407921,
    "repeatCount": 0,
    "Message": ""
}

Cancel Replay

A replay session can be canceled while it is running. Review the Cancel Replay DELETE API in the API Reference section and use the Cancel Replay request from the Postman collection referenced above. Press Send in Postman to cancel the replay session.

Export a Recorded Session

The current recorded session can be exported so that data can be saved to the file system. Review the Export GET API in the API Reference section and use the Export Recording requests from the Postman collection referenced above.

This API exports all the events, related devices and device profiles. It has an optional compression query parameter. Valid values are none, gzip and zlib . Defaults to none if not specified.

curl localhost:59712/api/v3/data?compression=gzip -o recording.gz
curl localhost:59712/api/v3/data?compression=zlib -o recording.zlib

Import a Record Session

This API allows a previously exported recording to be imported back into the service. Review the Import POST API in the API Reference section and use the Import Recording requests from the Postman collection referenced above.

This API has the optional overwrite query parameter, which specifies to overwrite existing Devices and Device Profiles or not. Defaults to true if not set.