apache/shenyu · error · IllegalArgumentException

Redis node URL cannot be null or empty

Error message

Redis node URL cannot be null or empty

What it means

RedisConnectionFactory.parseRedisNode() validates each node string used to build a Lettuce RedisNode. A null, blank, or whitespace-only node URL carries no host information, so an IllegalArgumentException is raised before any connection is attempted.

Solutions

1. Remove the blank entry from the Redis node configuration and supply a valid host (optionally host:port)
2. If a value comes from an env var, verify it is set before the admin/bootstrap starts
3. Trim and filter empty strings from the node list before constructing the connection factory

Example fix

// before
String[] nodes = redisUrl.split(",");
// after
List<String> nodes = Arrays.stream(redisUrl.split(","))
    .map(String::trim)
    .filter(s -> !s.isEmpty())
    .collect(Collectors.toList());

// validate node list before building the connection factory
List<String> nodes = configuredNodes == null ? List.of()
    : Arrays.stream(configuredNodes).map(String::trim).filter(s -> !s.isEmpty()).toList();
if (nodes.isEmpty()) throw new IllegalArgumentException("At least one Redis node URL is required");

try {
    factory.create(nodes);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("cannot be null or empty")) {
        logger.error("Redis node list contains a blank entry, check configuration", e);
    }
    throw e;
}

When it happens

Trigger: Passing null/empty entries in a Redis cluster/sentinel/standalone node list (e.g. shenyu.redis.node or cluster nodes config) so parseRedisNode receives an empty string after trimming.

Common situations: Environment-variable interpolation leaving the value empty; YAML list with a blank '-' entry; a node removed from config but a trailing comma left in a comma-separated string.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

• Port cannot be empty in Redis node URL: " + url
• Host is empty in Redis node URL: " + url
• client register param must config the appName or contextPath
• The configuration shenyu.discovery.serverList in xml/yml…
• OpenAPI pathKey cannot be null or empty

AI-assisted analysis of apache/shenyu@567142e072 (2026-09-12). Data as JSON: /api/errors/9e2bdbbe80202b13. Report an issue: GitHub.

Appendix: source

Thrown at shenyu-infra/shenyu-infra-redis/src/main/java/org/apache/shenyu/infra/redis/RedisConnectionFactory.java:139

        if (Objects.nonNull(redisConfigProperties.getPassword())) {
            config.setPassword(RedisPassword.of(redisConfigProperties.getPassword()));
        }
        config.setDatabase(redisConfigProperties.getDatabase());
        return config;
    }

    private List<RedisNode> createRedisNode(final String url) {
        List<RedisNode> redisNodes = new ArrayList<>();
        List<String> nodes = Lists.newArrayList(Splitter.on(";").split(url));
        for (String node : nodes) {
            redisNodes.add(parseRedisNode(node));
        }
        return redisNodes;
    }

    private RedisNode parseRedisNode(final String url) {
        if (Objects.isNull(url) || url.trim().isEmpty()) {
            throw new IllegalArgumentException("Redis node URL cannot be null or empty");
        }
        
        String trimmedUrl = url.trim();
        String host = trimmedUrl;
        int port = 6379;
        int bracketIndex = trimmedUrl.lastIndexOf("]");
        
        if (bracketIndex > -1) {
            // IPv6 address format: [::1] or [::1]:6379
            if (!trimmedUrl.startsWith("[")) {
                throw new IllegalArgumentException("Invalid IPv6 format in Redis node URL: " + url);
            }
            int closingBracket = trimmedUrl.indexOf("]");
            if (closingBracket == -1 || closingBracket != bracketIndex) {
                throw new IllegalArgumentException("Invalid IPv6 format in Redis node URL: " + url);
            }
            
            // Extract IPv6 address (remove brackets)

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