[KAFKA-16381] use volatile to guarantee KafkaMetric#config visibility across threads

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 3.8.0
• Assignee: Johnny Hsu
• Reporter: Johnny Hsu
• Created: 17/Mar/24 16:02
• Updated: 23/Mar/24 03:38
• Resolved: 23/Mar/24 03:38

Description

In KafkaMetirc.java, the getter is 

```
@Override
public MetricName metricName()

{ return this.metricName; }

```

and there is a setter 

```
public void config(MetricConfig config) {
    synchronized (lock)

{     this.config = config;   }

}
```

Since it's possible to set and get in the mean time, we should have lock in the getter as well

Issue Links

• links to: GitHub Pull Request #15550