apache/cassandra · error · InvalidRequestException

Can not create a keyspace with MetaReplicationStrategy

Error message

Can not create a keyspace with MetaReplicationStrategy

What it means

MetaReplicationStrategy (used for coordinated system metadata keyspaces) cannot be assigned to a user-created keyspace. CREATE KEYSPACE rejects any replication params that resolve to the meta replication strategy.

Solutions

1. Use SimpleStrategy or NetworkTopologyStrategy for user keyspaces.
2. Remove the MetaStrategy class from the replication map and pick a supported strategy.
3. Do not attempt to create keyspaces mirroring internal metadata replication; let Cassandra manage those.

Example fix

// before
CREATE KEYSPACE ks WITH replication = {'class': 'org.apache.cassandra.locator.MetaStrategy'};

// after
CREATE KEYSPACE ks WITH replication = {'class': 'NetworkTopologyStrategy', 'dc1': 3};

String cls = extractReplicationClass(cql); if (cls != null && cls.endsWith("MetaStrategy")) throw new IllegalArgumentException("MetaStrategy cannot be used for user keyspaces");

try { session.execute(ddl); } catch (InvalidQueryException e) { if (e.getMessage().contains("MetaReplicationStrategy")) { /* use a supported strategy */ } else throw e; }

When it happens

Trigger: `CREATE KEYSPACE ks WITH replication = {'class': 'org.apache.cassandra.locator.MetaStrategy'};` (or a subclass) — keyspaceMetadata.params.replication.isMeta() returns true in apply().

Common situations: Attempting to replicate the internal metadata keyspaces manually; copying replication configs out of internal schema/metadata keyspaces; experimentation with internal locator classes.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• Unable to use given strategy class: LocalStrategy is…
• Missing mandatory option
• Can not alter a keyspace to use MetaReplicationStrategy
• Cannot use keyspace inheriting fast path strategy with…
• Keyspace name ' ' doesn't match index name

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/0ee53f60a5a84522. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/cql3/statements/schema/CreateKeyspaceStatement.java:107

            if (ifNotExists)
                return schema;

            throw new AlreadyExistsException(keyspaceName);
        }

        // we deduplicate ReplicationParams here to use the same objects in KeyspaceMetadata
        // as we have as keys in metadata.placements to have a fast map lookup
        // ReplicationParams are immutable, so it is a safe optimization
        KeyspaceParams keyspaceParams = attrs.asNewKeyspaceParams();
        ReplicationParams replicationParams = metadata.placements().deduplicateReplicationParams(keyspaceParams.replication);
        keyspaceParams = keyspaceParams.withSwapped(replicationParams);
        KeyspaceMetadata keyspaceMetadata = KeyspaceMetadata.create(keyspaceName, keyspaceParams);

        if (keyspaceMetadata.params.replication.klass.equals(LocalStrategy.class))
            throw ire("Unable to use given strategy class: LocalStrategy is reserved for internal use.");

        if (keyspaceMetadata.params.replication.isMeta())
            throw ire("Can not create a keyspace with MetaReplicationStrategy");

        keyspaceMetadata.params.validate(keyspaceName, state, metadata);
        keyspaceMetadata.replicationStrategy.validateExpectedOptions(metadata);

        expandedCql = keyspaceMetadata.toCqlString(false, true, ifNotExists);
        verifyExpandedCql(expandedCql);
        return schema.withAddedOrUpdated(keyspaceMetadata);
    }

    SchemaChange schemaChangeEvent(KeyspacesDiff diff)
    {
        return new SchemaChange(Change.CREATED, keyspaceName);
    }

    public void authorize(ClientState client)
    {
        client.ensureAllKeyspacesPermission(Permission.CREATE);
    }

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