Logging of dependency libraries

Paul_Smedley · July 23, 2025, 9:14am

Hey All,

As some may have seen, I’m working on a binding for roborock vacuums. Right now, I’m only supporting cloud connections via the roborock mqtt servers.

Things initially work with status updates and commands both working. After some time, the status updates stop working, whilst mqtt seems to remain connected. (ie publishing commands still works, and running tcpdump on port 8883 generates enough incoming traffic to suggest that messages are still being received, but not being handled (for whatever reason).

I’m interested in seeing any logging from hivemq. I ran ‘openhab-cli console’ and used:

log:set TRACE com.hivemq.client.mqtt

To set the logging for hivemq - but nothing appears in openhab.log and I don’t see the output anywhere else?

Is it indeed possible to generate logging for the dependency libraries?

Cheers,

Paul

splatch · July 23, 2025, 11:01am

Double check if logging configuration permits trace logs to reach file. Sometimes appender may be set to ignore levels below certain threshold.
Within karaf/openhab shell you may try doing log:tail to tap it via embedded appender which retains entries only in memory and have no filters.

moe313 · July 23, 2025, 12:21pm

Hi Paul,

Great work on the Roborock binding — very cool project!

Regarding your issue with logging the HiveMQ MQTT client, you’re on the right track using:

bash

CopyEdit

log:set TRACE com.hivemq.client.mqtt

However, in many OpenHAB deployments, especially if you’re using the bundled HiveMQ client through the org.openhab.core.io.transport.mqtt module, the logging class might need to be more specific.

Try setting the TRACE log level for the following packages as well:

pgsql

CopyEdit

log:set TRACE org.openhab.core.io.transport.mqtt
log:set TRACE com.hivemq
log:set TRACE com.hivemq.client.internal

Also, ensure that the logs aren’t being filtered or redirected. You can verify by checking:

userdata/logs/openhab.log
userdata/logs/events.log
Or by watching live output with log:tail in the console.

If that still doesn’t give results, it could be that HiveMQ uses SLF4J and the logging backend isn’t hooked properly for the client logs. In that case, you might need to explicitly configure log4j2.xml under userdata/etc/ to include those packages with TRACE level.

Let me know if that helps — happy to dig deeper with you!

Cheers,

Paul_Smedley · July 23, 2025, 8:50pm

Thanks folks, I’ll try some of these ideas this evening.

Looks like hivemq natively uses Logback by default - Logging · hivemq/hivemq-community-edition Wiki · GitHub

wborn · July 24, 2025, 5:46am

That’s a wiki about their broker which we don’t use. We use their MQTT client which uses SLF4J when available:

github.com/hivemq/hivemq-mqtt-client

src/main/java/com/hivemq/client/internal/logging/InternalLoggerFactory.java

a7ae5ca95

/*
 * Copyright 2018-present HiveMQ and the HiveMQ Community
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.hivemq.client.internal.logging;

import com.hivemq.client.internal.util.ClassUtil;
import org.jetbrains.annotations.NotNull;

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Paul_Smedley · July 24, 2025, 6:50am

Thanks Wouter, should SLF4J be available by default?

I’m loading it at https://github.com/psmedley/openhab-addons/blob/roborock/bundles/org.openhab.binding.roborock/src/main/java/org/openhab/binding/roborock/internal/RoborockAccountHandler.java#L60

Paul_Smedley · July 24, 2025, 7:47am

I think I’ve tried all this to no avail. log4j2.xml has the hivemq entries after configuration by the gui, log:tail in the console doesn’t show anything, and there are no references to hivemq in any logs on /var/log/openhab/*.log

FYI my roborock binding isn’t using org.openhab.core.io.transport.mqtt, it’s using hivemq directly.

wborn · July 24, 2025, 1:03pm

The logging probably works fine. However there doesn’t seem to be much trace/debug logging, see:

https://github.com/hivemq/hivemq-mqtt-client/issues/411

logger usages:

Paul_Smedley · July 24, 2025, 7:40pm

I’m not seeing ANY logging from hivemq…

wborn · July 24, 2025, 8:20pm

Did you read the links? It only logs errors or warnings.

Paul_Smedley · July 24, 2025, 8:49pm

I had a better read now on the laptop, was looking on the phone earlier. Given the problems I’m seeing, I’m still surprised there is nothing from hivemq

wborn · July 25, 2025, 5:46am

You could also enable logging for the OH MQTT transport which may help with debugging issues:

org.openhab.core.io.transport.mqtt

Paul_Smedley · July 25, 2025, 8:39am

Thanks Wouter - I enabled org.openhab.core.io.transport.mqtt but still no mqtt logging. I guess I need to try run the binding under a debugger - new territory for me with java apps.

system · September 5, 2025, 12:39am

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