alibaba/spring-cloud-alibaba · error · IllegalArgumentException

ZookeeperDataSource server-addr is empty

Error message

ZookeeperDataSource server-addr is empty

What it means

Thrown by ZookeeperDataSourceProperties.preCheck when serverAddr is empty. Unlike other datasource properties, serverAddr has a default value ('localhost:2181'), so this error only fires when the property is explicitly set to empty OR cleared and the environment fallback also yields empty. The check first tries the env property 'spring.cloud.sentinel.datasource.zk.server-addr' as a fallback before throwing.

Source

Thrown at spring-cloud-alibaba-starters/spring-cloud-alibaba-sentinel-datasource/src/main/java/com/alibaba/cloud/sentinel/datasource/config/ZookeeperDataSourceProperties.java:54

	}

	private String serverAddr = "localhost:2181";

	private @Nullable String path;

	private @Nullable String groupId;

	private @Nullable String dataId;

	@Override
	public void preCheck(String dataSourceName) {
		if (StringUtils.isEmpty(serverAddr)) {
			Environment env = this.getEnv();
			if (env != null) {
				serverAddr = env.getProperty("spring.cloud.sentinel.datasource.zk.server-addr", "");
			}
			if (StringUtils.isEmpty(serverAddr)) {
				throw new IllegalArgumentException(
						"ZookeeperDataSource server-addr is empty");
			}
		}
	}

	public String getServerAddr() {
		return serverAddr;
	}

	public void setServerAddr(String serverAddr) {
		this.serverAddr = serverAddr;
	}

	public @Nullable String getPath() {
		return path;
	}

	public void setPath(@Nullable String path) {

View on GitHub (pinned to 115d590110)

Solutions

1. Set spring.cloud.sentinel.datasource.<name>.zk.server-addr=<zk-host:port> to a valid Zookeeper address, or set the global fallback spring.cloud.sentinel.datasource.zk.server-addr.
2. Remove any explicit empty-string override that clears the 'localhost:2181' default.
3. If using a placeholder (${ZK_ADDR}), ensure the environment variable is set to a non-empty value.

Example fix

# before (broken — server-addr explicitly empty)
spring:
  cloud:
    sentinel:
      datasource:
        ds1:
          zk:
            server-addr: ""
            path: /sentinel/rules

# after (fixed)
spring:
  cloud:
    sentinel:
      datasource:
        ds1:
          zk:
            server-addr: zk.local:2181
            path: /sentinel/rules

// Ensure serverAddr is set for zk Sentinel datasource
// Note: defaults to 'localhost:2181' but can be explicitly cleared
String serverAddr = props.getZk().getServerAddr();
if (!StringUtils.hasText(serverAddr)) {
    // Try the global fallback
    serverAddr = env.getProperty("spring.cloud.sentinel.datasource.zk.server-addr", "localhost:2181");
    props.getZk().setServerAddr(serverAddr);
}

When it happens

Trigger: Configuring a Sentinel datasource of type 'zk' with serverAddr explicitly set to empty string, or the default was overridden to empty AND spring.cloud.sentinel.datasource.zk.server-addr is also unset or empty. Since the field defaults to 'localhost:2181', this requires actively clearing it.

Common situations: 1) Developer sets spring.cloud.sentinel.datasource.<name>.zk.server-addr to an empty string or a placeholder that resolves to empty. 2) A profile override clears the default by setting server-addr to blank. 3) Programmatic configuration that sets serverAddr to null or empty after construction.

Related errors

• serverAddr, groupId, and dataId must not be null
• serverAddr and path must not be null
• ConsulDataSource server-host is empty
• ConsulDataSource ruleKey can not be empty
• [Sentinel Starter] DataSource {} file cannot be null

AI-assisted analysis of alibaba/spring-cloud-alibaba@115d590110 (2026-08-14). Data as JSON: /api/errors/446956827e43ea18. Report an issue: GitHub.