apache/iceberg · error · UncheckedIOException

Failed to write Spark view dependencies

Error message

Failed to write Spark view dependencies

What it means

SparkViewDependenciesParser.toJson() wraps Jackson serialization in try/catch and rethrows IOException as UncheckedIOException('Failed to write Spark view dependencies', e). It indicates the JSON tree could not be serialized, which is practically an internal failure since JsonNode-based generation rarely throws.

Source

Thrown at spark/v4.2/spark/src/main/java/org/apache/iceberg/spark/source/SparkViewDependenciesParser.java:74

        nameParts = ((TableDependency) dependency).nameParts();
      } else if (dependency instanceof FunctionDependency) {
        dependencyNode.put(TYPE, FUNCTION);
        nameParts = ((FunctionDependency) dependency).nameParts();
      } else {
        throw new IllegalArgumentException(
            "Unsupported Spark view dependency: " + dependency.getClass().getName());
      }

      ArrayNode namePartsNode = dependencyNode.putArray(NAME_PARTS);
      for (String namePart : nameParts) {
        namePartsNode.add(namePart);
      }
    }

    try {
      return MAPPER.writeValueAsString(dependenciesNode);
    } catch (IOException e) {
      throw new UncheckedIOException("Failed to write Spark view dependencies", e);
    }
  }

  static DependencyList fromJson(String json) {
    JsonNode node;
    try {
      node = MAPPER.readTree(json);
    } catch (IOException e) {
      throw new UncheckedIOException("Failed to parse Spark view dependencies", e);
    }

    Preconditions.checkArgument(
        node.isArray(), "Cannot parse Spark view dependencies from non-array: %s", node);
    ImmutableList.Builder<Dependency> dependenciesBuilder = ImmutableList.builder();
    for (JsonNode dependency : node) {
      String type = string(TYPE, dependency);
      String[] nameParts = stringArray(NAME_PARTS, dependency);
      switch (type) {

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Read the cause (getCause()) to see the underlying IOException/JsonMappingException
2. Check for duplicate/mismatched Jackson jars on the classpath (jackson-databind version conflicts)
3. Avoid mutating the dependenciesNode with non-serializable values in custom code paths
4. If persistent, capture the full stack trace and report with the Iceberg/Spark versions

try { json = SparkViewDependenciesParser.toJson(deps); } catch (UncheckedIOException e) { log.error("View dependency serialization failed: {}", e.getCause(), e); throw e; }

When it happens

Trigger: MAPPER.writeValueAsString(dependenciesNode) throwing IOException during view metadata persistence — e.g. JsonMappingException on an incompatible node structure from custom code injecting bad values.

Common situations: Corrupt or custom-built JsonNode graphs; ObjectMapper misconfiguration via shading/classpath conflicts with duplicate Jackson versions.

Understand the failure class

Background: "JSON serialization failed", "not JSON serializable", "Failed to serialize": why JSON marshaling errors happen and how to fix them — this error's family across 46 libraries.

Related errors

• Failed to write Spark view query column names
• Failed to parse Spark view dependencies
• Unsupported Spark view dependency type:
• Failed to read StreamingOffset from json
• Renaming a view is not supported by catalog: ${catalogName}

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/e9602dea67edc229. Report an issue: GitHub.