MQTT connection lost, again and again

Hello guys I need some help can’t figure out whats wrong. The connection to my MQTT server always breaks off. I don’t know why. The server and openhab has been restarted. I am using mqtt 1.x binding. It has been running for over a year without any problems.

Thanks for your help

log

2019-06-15 22:39:45.106 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting connection helper to periodically try restoring connection to broker 'mqtt'
2019-06-15 22:39:55.107 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting MQTT broker connection 'mqtt'
2019-06-15 22:40:05.222 [WARN ] [t.mqtt.internal.MqttBrokerConnection] - MQTT connection to 'mqtt' was lost: Connection lost : ReasonCode 32109 : Cause : null
2019-06-15 22:40:05.222 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting connection helper to periodically try restoring connection to broker 'mqtt'
2019-06-15 22:40:15.222 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting MQTT broker connection 'mqtt'
2019-06-15 22:40:25.285 [WARN ] [t.mqtt.internal.MqttBrokerConnection] - MQTT connection to 'mqtt' was lost: Connection lost : ReasonCode 32109 : Cause : null
2019-06-15 22:40:25.285 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting connection helper to periodically try restoring connection to broker 'mqtt'
2019-06-15 22:40:35.285 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting MQTT broker connection 'mqtt'
2019-06-15 22:40:45.871 [WARN ] [t.mqtt.internal.MqttBrokerConnection] - MQTT connection to 'mqtt' was lost: Connection lost : ReasonCode 32109 : Cause : null
2019-06-15 22:40:45.871 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting connection helper to periodically try restoring connection to broker 'mqtt'
2019-06-15 22:40:55.871 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting MQTT broker connection 'mqtt'
2019-06-15 22:41:06.029 [WARN ] [t.mqtt.internal.MqttBrokerConnection] - MQTT connection to 'mqtt' was lost: Connection lost : ReasonCode 32109 : Cause : null
2019-06-15 22:41:06.029 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting connection helper to periodically try restoring connection to broker 'mqtt'
2019-06-15 22:41:16.030 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting MQTT broker connection 'mqtt'
2019-06-15 22:41:26.109 [WARN ] [t.mqtt.internal.MqttBrokerConnection] - MQTT connection to 'mqtt' was lost: Connection lost : ReasonCode 32109 : Cause : null
2019-06-15 22:41:26.109 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting connection helper to periodically try restoring connection to broker 'mqtt'
2019-06-15 22:41:36.110 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting MQTT broker connection 'mqtt'
2019-06-15 22:41:46.161 [WARN ] [t.mqtt.internal.MqttBrokerConnection] - MQTT connection to 'mqtt' was lost: Connection lost : ReasonCode 32109 : Cause : null
2019-06-15 22:41:46.161 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting connection helper to periodically try restoring connection to broker 'mqtt'
2019-06-15 22:41:56.161 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting MQTT broker connection 'mqtt'
2019-06-15 22:42:06.238 [WARN ] [t.mqtt.internal.MqttBrokerConnection] - MQTT connection to 'mqtt' was lost: Connection lost : ReasonCode 32109 : Cause : null
2019-06-15 22:42:06.238 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting connection helper to periodically try restoring connection to broker 'mqtt'
2019-06-15 22:42:16.239 [INFO ] [t.mqtt.internal.MqttBrokerConnection] - Starting MQTT broker connection 'mqtt'

mqtt.cfg

mqtt.url=tcp://<ip>:1883
mqtt.clientId=openhab2

mqtt.config

mqtt.clientId="openhab2"
mqtt.url="tcp://<ip>:1883"
service.pid="org.openhab.mqtt"

thank you for your answer.I think the connection problems have been eliminated by themselves. The log file is free of messages. I hope it does not change.