apache/cassandra · error · IllegalArgumentException

data center(s) {datacenters} not found

Error message

data center(s) {datacenters} not found

What it means

After validating the local DC, createRepairTask checks that every requested datacenter actually has live endpoints registered in cluster metadata; any DC name with no known nodes causes IllegalArgumentException listing the missing names.

Source

Thrown at src/java/org/apache/cassandra/service/StorageService.java:3229

    }

    public TokenFactory getTokenFactory()
    {
        return ClusterMetadata.current().partitioner.getTokenFactory();
    }

    private FutureTask<Object> createRepairTask(final int cmd, final String keyspace, final RepairOption options, List<ProgressListener> listeners)
    {
        if (!options.getDataCenters().isEmpty() && !options.getDataCenters().contains(DatabaseDescriptor.getLocalDataCenter()))
        {
            throw new IllegalArgumentException("the local data center must be part of the repair; requested " + options.getDataCenters() + " but DC is " + DatabaseDescriptor.getLocalDataCenter());
        }
        Set<String> existingDatacenters = ClusterMetadata.current().directory.allDatacenterEndpoints().keys().elementSet();
        List<String> datacenters = new ArrayList<>(options.getDataCenters());
        if (!existingDatacenters.containsAll(datacenters))
        {
            datacenters.removeAll(existingDatacenters);
            throw new IllegalArgumentException("data center(s) " + datacenters.toString() + " not found");
        }

        RepairCoordinator task = new RepairCoordinator(this, cmd, options, keyspace);
        task.addProgressListener(progressSupport);
        for (ProgressListener listener : listeners)
            task.addProgressListener(listener);

        if (options.isTraced())
            return new FutureTaskWithResources<>(() -> ExecutorLocals::clear, task);
        return new FutureTask<>(task);
    }

    public RepairCoordinator newRepairCoordinator(String keyspace, RepairOption options)
    {
        int cmd = nextRepairCommand.incrementAndGet();
        return new RepairCoordinator(this, cmd, options, keyspace);
    }

View on GitHub (pinned to 88fd0f6a0e)

Solutions

1. Check exact DC names with nodetool describecluster or SELECT datacenter FROM system.peers (and local)
2. Fix the -dc spelling/case in the command or script
3. Wait for the new DC's nodes to join gossip, or remove the defunct DC name from the repair request

Example fix

// before
nodetool repair -dc DataCenter1 my_keyspace
// after
nodetool repair -dc datacenter1 my_keyspace   # name verified via nodetool describecluster

Set<String> existing = ClusterMetadata.current().directory.allDatacenterEndpoints().keys().elementSet();
List<String> missing = requestedDcs.stream().filter(dc -> !existing.contains(dc)).collect(toList());
if (!missing.isEmpty()) throw new IllegalArgumentException("unknown DCs: " + missing);

try { ss.repairAsync(ks, opt); } catch (IllegalArgumentException e) { /* re-derive DC names from cluster metadata */ }

When it happens

Trigger: `nodetool repair -dc <name>` where <name> is misspelled, renamed, or refers to a DC whose nodes are all down/decommissioned; calling StorageService.repairAsync programmatically with a stale DC name.

Common situations: Typos in -dc (case-sensitive); DC renamed in cassandra-rackdc.properties after a migration; scripted repairs referencing decommissioned datacenters; running repair before all nodes of a new DC have joined.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• the local data center must be part of the repair; requested
• Validation failed in {endpoint}
• REVOKE operation is not supported by AllowAllAuthorizer
• %s is not a valid data resource name
• %s is not a valid function resource name

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/292a0da632ce8947. Report an issue: GitHub.