apache/cassandra · error · IllegalArgumentException

Attempted to use message version " + messagingVersion + "…

Error message

Attempted to use message version " + messagingVersion + " which is smaller than " + versions[0] + " can handle (" + versions[0].messageVersion() + ")

What it means

Maps a cluster messaging version to the best supported Accord serializer Version. Because the enum only supports versions whose messageVersion is >= versions[0], a messaging version below the minimum cannot be negotiated and the method throws IllegalArgumentException. The scan relies on versions being ordered ascending, returning the first Version whose messageVersion is <= the requested one.

Solutions

1. Complete the rolling upgrade so all nodes meet the minimum messaging version required by Accord.
2. Disable Accord on nodes below the minimum messaging version.
3. Check the versions array ordering/support floor if modifying the enum, and document the minimum messaging version.

if (messagingVersion < Version.values()[0].messageVersion())
    throw new IllegalStateException("messagingVersion " + messagingVersion + " below Accord minimum " + Version.values()[0].messageVersion());

try {
    Version v = Version.findBestMatchForMessagingVersion(messagingVersion);
} catch (IllegalArgumentException e) {
    logger.error("Messaging version too low for Accord; upgrade peer", e);
    disableAccordForPeer();
}

When it happens

Trigger: Calling Version.findBestMatchForMessagingVersion(messagingVersion) with a value smaller than the lowest supported Accord messaging version.

Common situations: A pre-upgrade node (older messaging version) attempting to exchange Accord messages with fully upgraded nodes; cluster with mixed Cassandra versions where Accord is enabled but the old node's messaging version is too low.

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

• Expected version 0 for unversioned serializer
• Unknown version: " + version
• Unsupported record version
• Unsupported record version
• accord.cache_size option was set incorrectly to

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/de5876cf0706b36a. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/service/accord/serializers/Version.java:92

        {
            case 1: return V1;
            default:
                throw new IllegalArgumentException("Unknown version: " + version);
        }
    }

    public static Version findBestMatchForMessagingVersion(int messagingVersion)
    {
        Version[] versions = values();
        for (int i = versions.length - 1; i >= 0; i--)
        {
            Version v = versions[i];
            // If network version bumped (12 to 13), the accord serializers may not have been changed; use the largest
            // version smaller than or equal to this version
            if (v.messageVersion() <= messagingVersion)
                return v;
        }
        throw new IllegalArgumentException("Attempted to use message version " + messagingVersion + " which is smaller than " + versions[0] + " can handle (" + versions[0].messageVersion() + ")");
    }

    @Override
    public int messageVersion()
    {
        return messagingVersion.value;
    }

    public List<Version> greaterThanOrEqual()
    {
        Version[] all = Version.values();
        if (ordinal() == all.length - 1)
            return Collections.singletonList(this);
        List<Version> values = new ArrayList<>(all.length - ordinal());
        for (int i = ordinal(); i < all.length; i++)
            values.add(all[i]);
        return values;
    }

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