Status

Current state: Under Discussion

Discussion thread: here [Change the link from the KIP proposal email archive to your own email thread]

JIRA: KAFKA-15186 - Getting issue details... STATUS

Motivation

All Kafka component register AppInfo  metrics to track the application start time or commit-id etc. These metrics are useful for monitoring and debugging. However, the AppInfo doesn't provide client-id, which is an important information for custom metrics reporter. 

As the AppInfoParser  class registers a JMX MBean with the provided client-id but when it adds metrics to the Metrics registry the client-id is not included.

Public Interfaces

This approach would required modifying org.apache.kafka.common.utils.AppInfoParser.AppInfoMBean  interface to add a new method getClientId() .

Proposed Changes

The following code is a demonstration of how we will add to the getClientId method:

public interface AppInfoMBean {
    String getVersion();
    String getCommitId();
    Long getStartTimeMs();
    String getClientId();
}

Also updated AppInfoParser to include a new field CLIENT_ID, so that when reading /kafka/kafka-version.properties, the clientId can be retrieved.

public class AppInfoParser {
    private static final Logger log = LoggerFactory.getLogger(AppInfoParser.class);
    private static final String VERSION;
    private static final String COMMIT_ID;
	private static final String CLIENT_ID;

    protected static final String DEFAULT_VALUE = "unknown";

    static {
        Properties props = new Properties();
        try (InputStream resourceStream = AppInfoParser.class.getResourceAsStream("/kafka/kafka-version.properties")) {
            props.load(resourceStream);
        } catch (Exception e) {
            log.warn("Error while loading kafka-version.properties: {}", e.getMessage());
        }
        VERSION = props.getProperty("version", DEFAULT_VALUE).trim();
        COMMIT_ID = props.getProperty("commitId", DEFAULT_VALUE).trim();
		CLIENT_ID = props.getProperty("clientId", DEFAULT_VALUE).trim();
    }

	public static String getClientId() {
        return CLIENT_ID;
    }
}

Compatibility, Deprecation, and Migration Plan

Since this is a newly introduced behavior, there are no compatibility concerns.

Test Plan

change unit test or Integration test to verify the new method.

Rejected Alternatives

n/a