alibaba/nacos · error · NacosApiException

DATA_ACCESS_ERROR

DATA_ACCESS_ERROR

Error message

Failed to create ARD Skill artifact

What it means

Thrown when packaging a Skill into a ZIP artifact fails. skillArtifact() first queries the skill, then calls SkillUtils.toZipBytes(result.getSkill()) inside a try/catch. Any Exception (typically IOException from ZIP serialization or a malformed skill model) is wrapped as DATA_ACCESS_ERROR with HTTP 500. This is a server-side processing failure, not a client input error.

Source

Thrown at ai-registry-adaptor/src/main/java/com/alibaba/nacos/airegistry/service/ard/ArdArtifactService.java:105

        if (AiResourceConstants.RESOURCE_TYPE_MCP.equals(resourceType)) {
            McpServerDetailInfo detail = mcpServerOperationService.getMcpServerDetail(namespaceId,
                resourceName, mcpName, version);
            return new ArdArtifact(ArdProtocolConstants.MEDIA_TYPE_MCP, detail);
        }
        throw new NacosApiException(NacosException.INVALID_PARAM,
            ErrorCode.PARAMETER_VALIDATE_ERROR,
            "Unsupported ARD artifact resourceType: " + resourceType);
    }
    
    private ArdArtifact skillArtifact(String namespaceId, String resourceName, String version)
        throws NacosException {
        SkillQueryResult result =
            skillClientOperationService.querySkill(namespaceId, resourceName, version, null, null);
        try {
            return new ArdArtifact(ArdProtocolConstants.MEDIA_TYPE_SKILL_PACKAGE,
                SkillUtils.toZipBytes(result.getSkill()));
        } catch (Exception e) {
            throw new NacosApiException(NacosException.SERVER_ERROR,
                ErrorCode.DATA_ACCESS_ERROR, e, "Failed to create ARD Skill artifact");
        }
    }
    
    private ArdArtifact promptArtifact(String namespaceId, String resourceType,
        String resourceName, String version) throws NacosException {
        AiResourceVersion resourceVersion =
            readableOnlineVersion(namespaceId, resourceType, resourceName, version);
        byte[] bytes = readResourceFile(resourceVersion, namespaceId, resourceType, resourceName,
            version, PromptUtils.PROMPT_MAIN_DATA_ID);
        PromptVersionInfo prompt = JacksonUtils.toObj(new String(bytes, StandardCharsets.UTF_8),
            PromptVersionInfo.class);
        return new ArdArtifact(ArdProtocolConstants.MEDIA_TYPE_PROMPT, prompt);
    }
    
    private AiResourceVersion readableOnlineVersion(String namespaceId, String resourceType,
        String resourceName, String version) throws NacosException {
        AiResource meta = resourceManager.findMeta(namespaceId, resourceName, resourceType);

View on GitHub (pinned to 9b989acdf1)

Solutions

  1. Check the server logs for the wrapped cause (the original Exception is attached) to identify the serialization failure.
  2. Re-publish or repair the skill whose resourceName@version triggered the error, ensuring all required skill files are present.
  3. Verify the skill model version matches the SkillUtils.toZipBytes implementation (no client/server model skew).
  4. If transient I/O, retry the artifact request once.
Defensive patterns

Strategy: try-catch

Try / catch

try {
    ArdArtifact artifact = ardArtifactService.get(ns, "skill", name, version, null);
} catch (NacosApiException e) {
    if (ErrorCode.DATA_ACCESS_ERROR.equals(e.getErrorCode())) {
        log.error("Skill artifact packaging failed for {}@{}", name, version, e);
        // surface a retry or re-publish guidance to the operator
    } else {
        throw e;
    }
}

Prevention

When it happens

Trigger: Requesting an ARD artifact for a skill whose underlying Skill object cannot be serialized to a ZIP (e.g., a skill with missing required artifact files, a null/binary-incompatible skill model, or a filesystem/encoding error during zip construction). The skill must already exist (querySkill succeeded) but its content is malformed.

Common situations: A skill was registered with incomplete or corrupted artifact data; a version upgrade changed the Skill model shape so toZipBytes hits a null field; transient I/O pressure on the server during ZIP streaming; a skill published through a buggy importer.

Related errors

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/17212c0427439491. Report an issue: GitHub.