apache/cassandra · error · IllegalArgumentException

ParamType id must be non-negative

Error message

ParamType id must be non-negative

What it means

The ParamType enum constructor validates that each message-parameter type has a non-negative wire id, since ids index into a lookup array for serialization. A negative id is a programming error in the enum definition and throws IllegalArgumentException at class initialization.

Solutions

1. Assign a unique non-negative id to the new ParamType constant
2. Check merge conflicts in ParamType.java and restore correct ids
3. Pick an id not already used by any ParamType (see the idToTypeMap construction)
4. Add a CI test that forces ParamType class initialization to catch bad ids early

Example fix

// before
ParamType CUSTOM(-1, serializer),
// after
ParamType CUSTOM(9, serializer), // unique, non-negative id

// at class-init/CI time
for (ParamType t : ParamType.values()) if (t.id < 0) throw new IllegalStateException("bad id: " + t);

When it happens

Trigger: Defining/patching a ParamType constant with a negative id — only reachable when modifying the enum source (contributor/fork error), not by normal API use.

Common situations: Developers adding custom parameters in forks or backport patches; merge conflicts that mangle id assignments in the ParamType enum.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Two ParamType-s that map to the same id: + type.id
• Cannot instantiate a non-virtual table
• Attempted to encode a response with an unset stream id:
• Cannot convert value
• Cannot decode string as UTF8: '" +…

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/16d53c28bff43dfc. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/net/ParamType.java:71

    LOCAL_READ_SIZE_FAIL             (10, Int64Serializer.serializer),
    LOCAL_READ_SIZE_WARN             (11, Int64Serializer.serializer),
    ROW_INDEX_READ_SIZE_FAIL         (12, Int64Serializer.serializer),
    ROW_INDEX_READ_SIZE_WARN         (13, Int64Serializer.serializer),
    CUSTOM_MAP                       (14, CustomParamsSerializer.serializer),
    TOO_MANY_REFERENCED_INDEXES_WARN (16, Int32Serializer.serializer),
    TOO_MANY_REFERENCED_INDEXES_FAIL (17, Int32Serializer.serializer),
    WRITE_SIZE_WARN                  (18, WriteThresholdMapSerializer.serializer),
    WRITE_TOMBSTONE_WARN             (19, WriteThresholdMapSerializer.serializer),
    ACCORD_TRACING                   (20, AccordRemoteTracing.tracingSerializer),
    ;

    final int id;
    final IVersionedSerializer serializer;

    ParamType(int id, IVersionedSerializer serializer)
    {
        if (id < 0)
            throw new IllegalArgumentException("ParamType id must be non-negative");

        this.id = id;
        this.serializer = serializer;
    }

    private static final ParamType[] idToTypeMap;

    static
    {
        ParamType[] types = values();

        int max = -1;
        for (ParamType t : types)
            max = max(t.id, max);

        ParamType[] idMap = new ParamType[max + 1];

        for (ParamType type : types)

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