TCP Broken pipe on disconnect / reconnect

[souyamafountlab]

🐞 Bug Report

Affected Services [REQUIRED]

The issue is located in: device-modbus-go

Is this a regression?

Kinda.

The code at v3.1 used to open and close connection for each read request, which would give problems at high freqnency polls for certain devices. The current fix of using a client map keeps a persistent connection. Now in case the connection ever drops even temporarily, read/write requests fails until the container is restarted.

Description and Minimal Reproduction [REQUIRED]

Connect any modbus device over TCP and start polling such as through autoevents. Disconnect and reconnect the device to the network.

🔥 Exception or Error

level=ERROR ts=2025-01-15T11:51:55.458149687Z app=device-modbus source=executor.go:55 msg="AutoEvent - error occurs when reading resource DI8: error reading Regex DeviceResource(s) DI8 for DVC_1 -> write tcp 172.18.0.10:55972->XXX.XXX.XXX.XXX:502: write: broken pipe"
2025/01/15 17:21:55 modbus: sending 0b 32 00 00 00 06 03 02 00 0d 00 01
level=INFO ts=2025-01-15T11:51:55.459155047Z app=device-modbus source=driver.go:137 msg="Read command failed. Cmd:DI13 err:write tcp 172.18.0.10:55972->XXX.XXX.XXX.XXX:502: write: broken pipe \n"
level=ERROR ts=2025-01-15T11:51:55.459204454Z app=device-modbus source=executor.go:55 msg="AutoEvent - error occurs when reading resource DI13: error reading Regex DeviceResource(s) DI13 for DVC_1 -> write tcp 172.18.0.10:55972->XXX.XXX.XXX.XXX:502: write: broken pipe"
2025/01/15 17:21:55 modbus: sending 0b 33 00 00 00 06 03 02 00 0c 00 01
level=INFO ts=2025-01-15T11:51:55.459254348Z app=device-modbus source=driver.go:137 msg="Read command failed. Cmd:DI12 err:write tcp 172.18.0.10:55972->XXX.XXX.XXX.XXX:502: write: broken pipe \n"
level=ERROR ts=2025-01-15T11:51:55.459301749Z app=device-modbus source=executor.go:55 msg="AutoEvent - error occurs when reading resource DI12: error reading Regex DeviceResource(s) DI12 for DVC_1 -> write tcp 172.18.0.10:55972->XXX.XXX.XXX.XXX:502: write: broken pipe"
2025/01/15 17:21:55 modbus: sending 0b 34 00 00 00 06 03 02 00 09 00 01
level=INFO ts=2025-01-15T11:51:55.459347214Z app=device-modbus source=driver.go:137 msg="Read command failed. Cmd:DI9 err:write tcp 172.18.0.10:55972->XXX.XXX.XXX.XXX:502: write: broken pipe \n"

🌍 Your Environment

Deployment Environment:

EdgeX Version [REQUIRED]:
Latest code at commit 2f075c7

Anything else relevant?

[cloudxxx8]

If the command is failed, the connection should be removed from the cache to allow re-establish connection next time.