apache/cassandra · error · IllegalArgumentException

Invalid value for %s: %s

Error message

Invalid value for %s: %s

What it means

When resolving training parameters (max dictionary size, max total sample size), internalTrainingParameterResolution parses the user-supplied value as a DataStorageSpec.IntBytesBound. If parsing or validation of the resolved value fails for any reason, the method wraps it into an IllegalArgumentException with the message 'Invalid value for <parameter>: <value>'.

Source

Thrown at src/java/org/apache/cassandra/db/compression/CompressionDictionaryTrainingConfig.java:158

    private static int internalTrainingParameterResolution(CompressionParams compressionParams,
                                                           String userSuppliedValue,
                                                           String parameterName,
                                                           String defaultParameterValue)
    {
        String resolvedValue = null;
        try
        {
            if (userSuppliedValue == null)
                resolvedValue = compressionParams.getOtherOptions().getOrDefault(parameterName, defaultParameterValue);
            else
                resolvedValue = userSuppliedValue;

            return new DataStorageSpec.IntBytesBound(resolvedValue).toBytes();
        }
        catch (Throwable t)
        {
            throw new IllegalArgumentException(String.format("Invalid value for %s: %s", parameterName, resolvedValue));
        }
    }

    /**
     * Validates value of a parameter for training purposes. The value to validate should
     * be accepted by {@link DataStorageSpec.IntKibibytesBound}. This method is used upon validation
     * of input parameters in the implementations of dictionary compressor.
     *
     * @param parameterName name of a parameter to validate
     * @param resolvedValue value to validate
     * @return resolved value in bytes
     */
    static int validateSizeBasedTrainingParameter(String parameterName, String resolvedValue)
    {
        try
        {
            return new DataStorageSpec.IntBytesBound(resolvedValue).toBytes();
        }

View on GitHub (pinned to 88fd0f6a0e)

Solutions

1. Pass a valid DataStorageSpec string, e.g. '64MiB' or '1024KiB', within the allowed bound for the parameter.
2. Omit the parameter so the configured default is used instead of an invalid override.
3. Check the accepted unit and maximum (IntKibibytesBound) documented for the parameter.
4. Verify quoting when passing values through nodetool/JMX so unit suffixes are not stripped.

Example fix

// before
params.put("max_dictionary_size", "100 MB"); // unparsable / out of bound
// after
params.put("max_dictionary_size", "100MiB");
manager.train(true, params);

try { new DataStorageSpec.IntBytesBound(value); } catch (IllegalArgumentException e) { throw new IllegalArgumentException("bad training param: " + value, e); }

try { manager.train(force, params); } catch (IllegalArgumentException e) { if (e.getMessage().startsWith("Invalid value for")) { /* fix the parameter string and retry */ } else throw e; }

When it happens

Trigger: Passing a training parameter (e.g. max_dictionary_size, max_total_sample_size) whose value cannot be parsed by DataStorageSpec.IntBytesBound — non-numeric strings, negative values, values exceeding the IntKibibytesBound maximum, wrong units, or empty strings.

Common situations: Passing plain integers where a storage spec string is expected or vice versa ('100MB' vs '100'); exceeding the KiB-bound maximum; typos like '100 Mb'; passing parameters via JMX/nodetool where quoting strips or mangles units; locale-dependent decimal separators.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• Table <keyspaceName>.<tableName> does not support dictionary
• No SSTables available for training in table <keyspaceName>.<
• The next training or importing can occur only at least after
• Training already in progress for table <keyspaceName>.<table
• compressed_read_ahead_buffer_size must be at least 256KiB (s

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/8c69bfebc19181bc. Report an issue: GitHub.