What causes "Invalid host/port configuration. Host: ${host} Port: ${port}" in zhisheng17/flink-learning?

Set metrics.reporter. .host= and metrics.reporter. .port=9091 in flink-conf.yaml.

zhisheng17/flink-learning · error · IllegalArgumentException

Invalid host/port configuration. Host: ${host} Port: ${port}

Error message

Invalid host/port configuration. Host: ${host} Port: ${port}

What it means

PrometheusPushGatewayReporter validates its host and port config in open(). It throws IllegalArgumentException when hostFromConfig is null/empty or the configured port is less than 1, because a Pushgateway endpoint cannot be built without them.

Source

Thrown at flink-learning-extends/flink-metrics/flink-metrics-prometheus/src/main/java/org/apache/flink/metrics/prometheus/PrometheusPushGatewayReporter.java:68

	private Map<String, String> groupingKey;
	private String appId;
	private String taskName;
	private String taskId;

	@Override
	public void open(MetricConfig config) {
		super.open(config);

		String host = config.getString(HOST.key(), HOST.defaultValue());
		int port = config.getInteger(PORT.key(), PORT.defaultValue());
		String clusterMode = config.getString(CLUSTER_MODE.key(), CLUSTER_MODE.defaultValue());
		String configuredJobName = config.getString(JOB_NAME.key(), JOB_NAME.defaultValue());
		boolean randomSuffix = config.getBoolean(RANDOM_JOB_NAME_SUFFIX.key(), RANDOM_JOB_NAME_SUFFIX.defaultValue());
		deleteOnShutdown = config.getBoolean(DELETE_ON_SHUTDOWN.key(), DELETE_ON_SHUTDOWN.defaultValue());
		groupingKey = parseGroupingKey(config.getString(GROUPING_KEY.key(), GROUPING_KEY.defaultValue()));

		if (host == null || host.isEmpty() || port < 1) {
			throw new IllegalArgumentException(
				"Invalid host/port configuration. Host: " + host + " Port: " + port);
		}

		Properties properties = System.getProperties();
		taskName = properties.getProperty("taskName", null);
		taskId = properties.getProperty("taskId", null);

		String jobNamePrefix = "";
		if (!StringUtils.isNullOrWhitespaceOnly(clusterMode) && clusterMode
			.toUpperCase()
			.equals(ClusterMode.YARN.name())) {
			//yarn cluster
			appId = System.getenv("_APP_ID");
			if (!StringUtils.isNullOrWhitespaceOnly(appId)) {
				jobNamePrefix = appId + "_jobmanager";
			} else {
				String pwd = System.getenv("PWD");
				String[] values = pwd.split(File.separator);

View on GitHub (pinned to d731cee761)

Solutions

Set metrics.reporter.<name>.host=<pushgateway-host> and metrics.reporter.<name>.port=9091 in flink-conf.yaml.
Ensure the keys use the exact same <name> prefix as metrics.reporter.<name>.factory.class.
Verify the Pushgateway is running and reachable at host:9091.
Restart the Flink cluster/job so the reporter picks up new config.

Example fix

# before
metrics.reporter.promgateway.factory.class: org.apache.flink.metrics.prometheus.PrometheusPushGatewayReporterFactory
# after
metrics.reporter.promgateway.factory.class: org.apache.flink.metrics.prometheus.PrometheusPushGatewayReporterFactory
metrics.reporter.promgateway.host: pushgateway-host
metrics.reporter.promgateway.port: 9091

Defensive patterns

Strategy: validation

Validate before calling

String host = config.getString("metrics.reporter.promgateway.host", "");
int port = config.getInteger("metrics.reporter.promgateway.port", -1);
if (host == null || host.isEmpty() || port < 1)
    throw new IllegalStateException("promgateway reporter needs non-empty host and port >= 1");

Try / catch

try {
    reporter.open(metrics);
} catch (IllegalArgumentException e) {
    LOG.error("PushGateway reporter misconfigured: {}", e.getMessage());
    throw e; // config error should fail fast
}

Prevention

Always set host and port keys with the same reporter name prefix
Validate flink-conf.yaml reporter blocks in CI
Use port 9091 (Pushgateway default) unless customized
Watch for YAML indentation errors that silently drop keys

When it happens

Trigger: flink-conf.yaml metrics.reporter.<name>.host missing or empty, or .port set to 0/negative/garbage; config keys misspelled so defaults (null/0) are used.

Common situations: Misconfigured flink-conf.yaml reporter block; port typo like 'port: -1'; enabling the reporter without adding its host/port options; YAML indentation putting keys under the wrong reporter prefix.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

AI-assisted analysis of zhisheng17/flink-learning@d731cee761 (2026-09-06). Data as JSON: /api/errors/e23a9b676b43ae33. Report an issue: GitHub.