apache/cassandra · warning

Addresses differ: !=

Error message

Addresses differ: {} != {}

What it means

WARN log from Directory.dumpDiff(Directory) indicating the addresses maps (NodeId to InetAddress) differ between two Directory snapshots. Divergent addresses mean one view maps a node ID to a different IP, or knows an address the other does not — often a symptom of node replacement or a peers-map divergence. Diagnostic output, not an exception.

Solutions

1. Complete or replay the Replace transformation so both views record the new address for the node ID
2. Replay missed cluster metadata log entries on the stale node
3. Check broadcast_address/broadcast_address settings are correct on each node so registration addresses match expectations
4. Restart the diverging node to resync cluster metadata from the CMS

// Confirm replacement operations are fully committed before diffing addresses
if (dirA.addresses().entrySet().stream()
        .allMatch(e -> e.getValue().equals(dirB.addresses().get(e.getKey()))))
    // addresses agree; nothing to diff
    return;

When it happens

Trigger: dumpDiff(other) when Objects.equals(addresses, other.addresses) is false; commonly after a node was replaced (new IP, same logical node) in one view, or an address change was committed but not yet replicated.

Common situations: Replacement of a failed node with a new IP while another member still holds the old address; snapshots compared across a replace operation; incorrect broadcast_address configuration causing address registration mismatches.

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

• Did not get response from
• Endpoints by dc differ
• Last modified differ
• Locations differ: !=
• nextId differ: !=

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/5e788073aaeffecb. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/tcm/membership/Directory.java:935

            dumpDiff(logger, states, other.states);
        }
        if (!Objects.equals(endpointsByDC, other.endpointsByDC))
        {
            logger.warn("Endpoints by dc differ: {} != {}", endpointsByDC, other.endpointsByDC);
            dumpDiff(logger, endpointsByDC.asMap(), other.endpointsByDC.asMap());
        }
        if (!Objects.equals(racksByDC, other.racksByDC))
        {
            logger.warn("Racks by dc differ: {} != {}", racksByDC, other.racksByDC);
        }
        if (!Objects.equals(versions, other.versions))
        {
            logger.warn("Versions differ: {} != {}", versions, other.versions);
            dumpDiff(logger, versions, other.versions);
        }
        if (!Objects.equals(addresses, other.addresses))
        {
            logger.warn("Addresses differ: {} != {}", addresses, other.addresses);
            dumpDiff(logger, addresses, other.addresses);
        }
    }

    public static <K, V> void dumpDiff(Logger logger, Map<K, V> l, Map<K, V> r)
    {
        for (K k : Sets.intersection(l.keySet(), r.keySet()))
        {
            V lv = l.get(k);
            V rv = r.get(k);
            if (!Objects.equals(lv, rv))
                logger.warn("Values for key {} differ: {} != {}", k, lv, rv);
        }
        for (K k : Sets.difference(l.keySet(), r.keySet()))
            logger.warn("Value for key {} is only present in the left set: {}", k, l.get(k));
        for (K k : Sets.difference(r.keySet(), l.keySet()))
            logger.warn("Value for key {} is only present in the right set: {}", k, r.get(k));

View on GitHub (pinned to 88fd0f6a0e)