apache/cassandra · warning

Locked ranges differ

Error message

Locked ranges differ: {} != {}

What it means

ClusterMetadata's equivalence/diff check compares this metadata against another snapshot. When lockedRanges differs, it logs 'Locked ranges differ: {} != {}' as a warning (not thrown). This diagnostic runs when validating/reconciling two ClusterMetadata views (e.g. loading from log vs. computed state) and indicates the locked-ranges component diverged between them.

Solutions

1. Re-run the comparison after quiescing range-locking operations (finish active repairs) to see if the difference is transient
2. Restart/realign the node's TCM state (force refresh from the current epoch)
3. Check preceding 'Placements differ' / other diff warnings to characterize the divergence; report to the project if reproducible (likely a TCM bug)
4. Verify all CMS members are on the same epoch and no node has a stale log

// before diffing metadata, ensure no in-flight range operations
if (ClusterMetadata.current().lockedRanges.size() > 0)
    logger.warn("Active range locks may cause diff mismatch; quiesce repairs first");

When it happens

Trigger: Replaying the TCM commit log or comparing an in-memory ClusterMetadata against a serialized/recomputed copy where lockedRanges (range locks held by operations like repairs) do not match.

Common situations: Concurrent range-locking operations (repairs/maintenance) during snapshot/replay; a bug in diffing or serialization; partial log replay after crash.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• Couldn't commit the transformation. Is the node shutting…
• Illegal state:
• Initializing with cluster metadata from
• Last modified differ
• nextId differ: !=

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/d6c789e14f8ac9bc. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/tcm/ClusterMetadata.java:1263

        }
        if (!directory.equals(other.directory))
        {
            logger.warn("Directories differ:");
            directory.dumpDiff(other.directory);
        }
        if (!tokenMap.equals(other.tokenMap))
        {
            logger.warn("Token maps differ:");
            tokenMap.dumpDiff(other.tokenMap);
        }
        if (!placements.equals(other.placements))
        {
            logger.warn("Placements differ:");
            placements.dumpDiff(other.placements);
        }
        if (!lockedRanges.equals(other.lockedRanges))
        {
            logger.warn("Locked ranges differ: {} != {}", lockedRanges, other.lockedRanges);
        }
        if (!inProgressSequences.equals(other.inProgressSequences))
        {
            logger.warn("In progress sequences differ: {} != {}", inProgressSequences, other.inProgressSequences);
        }
        if (!extensions.equals(other.extensions))
        {
            logger.warn("Extensions differ: {} != {}", extensions, other.extensions);
        }
        if (!cmsMembership.equals(other.cmsMembership))
        {
            logger.warn("CMS Membership differ: {} != {}", cmsMembership, other.cmsMembership);
        }
    }

    @Override
    public int hashCode()
    {

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