apache/cassandra · error · IllegalStateException

CompactionStress does not support secondary indexes

Error message

CompactionStress does not support secondary indexes

What it means

CompactionStress loads existing SSTables into a ColumnFamilyStore so compaction strategies can be exercised offline. It explicitly skips registering the SSTables with any indexes; if the loaded table already has secondary indexes defined (indexManager.hasIndexes()), the tool throws IllegalStateException because compaction-stress cannot reproduce index-driven behavior and would produce misleading results. This is a deliberate unsupported-feature guard, not a corruption indicator.

Source

Thrown at tools/stress/src/org/apache/cassandra/stress/CompactionStress.java:160

                    continue;

                try
                {
                    SSTableReader sstable = SSTableReader.openNoValidation(entry.getKey(), components, cfs);
                    sstables.add(sstable);
                }
                catch (Exception e)
                {
                    JVMStabilityInspector.inspectThrowable(e);
                    System.err.println(String.format("Error Loading %s: %s", entry.getKey(), e.getMessage()));
                }
            }

            cfs.disableAutoCompaction();

            // We want to add the SSTables without firing their indexing by any eventual unsupported 2i
            if (cfs.indexManager.hasIndexes())
                throw new IllegalStateException("CompactionStress does not support secondary indexes");

            //Register with cfs
            cfs.addSSTables(sstables);
        }

        return cfs;
    }

    StressProfile getStressProfile()
    {
        try
        {
            File yamlFile = new File(profile);
            return StressProfile.load(yamlFile.exists() ? yamlFile.toURI() : URI.create(profile));
        }
        catch ( IOError e)
        {
            e.printStackTrace();

View on GitHub (pinned to 88fd0f6a0e)

Solutions

1. Remove or drop the secondary indexes from the schema used for the stress run (edit the schema DDL / options provided to compactionstress).
2. Run compactionstress on a copy of the table whose schema has no indexes defined.
3. If you need to test index compaction behavior, use a full cluster with real writes instead of compactionstress.
4. Wrap the invocation to catch IllegalStateException and print guidance that 2i tables are unsupported.

Example fix

// before
CREATE TABLE ks.t (k int PRIMARY KEY, v text);
CREATE INDEX t_v_idx ON ks.t (v);
// after
CREATE TABLE ks.t (k int PRIMARY KEY, v text); // no index for compactionstress

// before running compactionstress, inspect schema for indexes:
// cqlsh -e "DESCRIBE TABLE ks.t" | grep -i "CREATE INDEX"
boolean hasIndexes = schemaDDL.toUpperCase().contains("CREATE INDEX");
if (hasIndexes) throw new IllegalStateException("compactionstress unsupported for indexed tables");

try {
    compactionStress.initCf(...);
} catch (IllegalStateException e) {
    if (e.getMessage().contains("secondary indexes")) {
        System.err.println("Drop indexes from the schema or use a full cluster for this table.");
        return;
    }
    throw e;
}

When it happens

Trigger: Running compactionstress against a table (schema loaded from the sstable's schema or a provided schema) that has secondary indexes defined, i.e. cfs.indexManager.hasIndexes() returns true after the SSTables are inspected in initCf.

Common situations: Pointing compactionstress at SSTables dumped from a production table that has 2i/SAI indexes defined in its schema; forgetting that indexes are part of the table schema even if the dumped files contain no index data.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Unsupported disk access mode for compaction_read_disk_access
• concurrent_compactors should be strictly greater than 0, but
• Invalid value of compaction_throughput:
• compaction_throughput: is too large; it should be less than
• max_concurrent_automatic_sstable_upgrades can't be negative

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/afb01b8ecffdaa30. Report an issue: GitHub.