apache/cassandra · error · InvalidRequestException

Cannot drop keyspace

Error message

Cannot drop keyspace '%s' as it contains accord tables which are currently being dropped. Please wait for those operations to complete before dropping the keyspace. (%s)

What it means

DROP KEYSPACE was rejected because the keyspace contains Accord-enabled tables currently in the process of being dropped (params.pendingDrop). Dropping the keyspace now would race with those in-flight table drops, so Cassandra refuses until they complete.

Solutions

Wait for the pending table drops to complete (tables are listed in the error), then retry DROP KEYSPACE.
Poll system_schema.tables or driver schema metadata until the listed tables disappear.
Retry DROP KEYSPACE with a backoff loop.

Example fix

// before
DROP KEYSPACE ks; // issued right after DROP TABLE ks.txn
// after
-- wait until pending tables vanish, then:
DROP KEYSPACE ks;

Defensive patterns

Strategy: retry

Validate before calling

boolean pending = schema.getKeyspace(ks).tables.stream()
    .anyMatch(t -> t.params.pendingDrop);
if (pending) scheduleRetryAfterSchemaAgreement();

Try / catch

catch (InvalidRequestException e) { if (e.getMessage().contains("currently being dropped")) { retryWithBackoff(); } else throw e; }

Prevention

Wait for schema agreement after dropping Accord tables before dropping the keyspace
Serialize keyspace teardown after table teardown
Monitor pendingDrop state in maintenance tooling

When it happens

Trigger: DROP KEYSPACE ks while any table in ks has params.pendingDrop == true, i.e. a DROP TABLE on an Accord transactional table was initiated but not finished.

Common situations: Re-issuing DROP KEYSPACE immediately after DROP TABLE on an Accord-backed table while the async drop propagates through the cluster; test teardown dropping keyspaces too quickly.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/6f799f5f1763dfae. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/cql3/statements/schema/DropKeyspaceStatement.java:68

    {
        return metadata.directory.commonSerializationVersion.isAtLeast(Version.V0);
    }

    @Override
    public Keyspaces apply(ClusterMetadata metadata)
    {
        Guardrails.dropKeyspaceEnabled.ensureEnabled(state);

        Keyspaces schema = metadata.schema.getKeyspaces();
        KeyspaceMetadata keyspace = schema.getNullable(keyspaceName);
        if (keyspace != null)
        {
            // check that no accord tables in the keyspace are currently in the process of being dropped
            List<TableMetadata> pendingDrop = keyspace.tables.stream()
                                                             .filter(t -> t.params.pendingDrop)
                                                             .collect(Collectors.toList());
            if (!pendingDrop.isEmpty())
                throw ire("Cannot drop keyspace '%s' as it contains accord tables which are currently being dropped. " +
                          "Please wait for those operations to complete before dropping the keyspace. (%s)",
                          keyspaceName, pendingDrop.stream()
                                                   .map(Object::toString)
                                                   .collect(Collectors.joining(",")));

            List<TableMetadata> accordTables = keyspace.tables.stream()
                                               .filter(TableMetadata::requiresAccordSupport)
                                               .collect(Collectors.toList());
            if (!accordTables.isEmpty())
                throw ire("Cannot drop keyspace '%s' as it contains accord tables. (%s)",
                          keyspaceName, accordTables.stream()
                                                   .map(Object::toString)
                                                   .collect(Collectors.joining(",")));
            return schema.without(keyspaceName);
        }

        if (ifExists)
            return schema;

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