apache/cassandra · error · java.io.IOException

When specifying the Keyspace table list (using…

Error message

When specifying the Keyspace table list (using -kt,--kt-list,-kc,--kc.list), you must not also specify keyspaces to snapshot

What it means

When snapshotting a specific keyspace-table list via -kt/--kt-list/-kc/--kc.list, you cannot additionally pass positional keyspace arguments or a --table filter; the table list is exclusive with the other selection mechanisms. Snapshot.execute() throws IOException when both are provided.

Solutions

Use only -kt/--kc.list with the full keyspace.table list, dropping positional keyspaces and --table.
Or drop -kt and select tables with positional keyspaces plus --table instead.
Update automation scripts to use one selection style consistently.

Example fix

// before
nodetool snapshot -kt ks1.tbl1,ks2.tbl2 ks1 --table tbl1
// after
nodetool snapshot -kt ks1.tbl1,ks2.tbl2

Defensive patterns

Strategy: validation

Validate before calling

if (ktList != null && !ktList.isEmpty() && (!keyspaces.isEmpty() || table != null)) throw new IllegalArgumentException('-kt is mutually exclusive with positional keyspaces and --table');

Try / catch

try { snapshot(ktList, keyspaces, table); } catch (IOException e) { if (e.getMessage().contains("you must not also specify keyspaces")) dropRedundantSelectors(); else throw e; }

Prevention

Pick one table-selection style (-kt list OR keyspaces/--table) per command
Audit scripts migrating from old syntax to -kt for leftover positional args

When it happens

Trigger: Running e.g. `nodetool snapshot -kt ks1.tbl1 ks2` or `nodetool snapshot -kt ks1.tbl1 --table tbl2`, i.e. keyspaces list or table non-empty while ktList is set.

Common situations: Users combining the modern -kt syntax with the older positional keyspace/--table syntax in the same command, often when converting old scripts.

Related errors

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/94cd779be27b80da. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/tools/nodetool/Snapshot.java:90

            options.put(SnapshotOptions.SKIP_FLUSH, Boolean.toString(skipFlush));
            if (null != ttl) {
                DurationSpec.LongNanosecondsBound d = new DurationSpec.LongNanosecondsBound(ttl);
                options.put(SnapshotOptions.TTL, d.toString());
            }

            if (!snapshotName.isEmpty() && snapshotName.contains(File.pathSeparator()))
            {
                throw new IOException("Snapshot name cannot contain " + File.pathSeparator());
            }
            // Create a separate path for kclist to avoid breaking of already existing scripts
            if (null != ktList && !ktList.isEmpty())
            {
                ktList = ktList.replace(" ", "");
                if (keyspaces.isEmpty() && null == table)
                    sb.append('[').append(ktList).append(']');
                else
                {
                    throw new IOException(
                            "When specifying the Keyspace table list (using -kt,--kt-list,-kc,--kc.list), you must not also specify keyspaces to snapshot");
                }
                if (!snapshotName.isEmpty())
                    sb.append(" with snapshot name [").append(snapshotName).append(']');
                sb.append(" and options ").append(options);
                out.println(sb);
                probe.takeMultipleTableSnapshot(snapshotName, options, ktList.split(","));
                out.println("Snapshot directory: " + snapshotName);
            }
            else
            {
                if (keyspaces.isEmpty())
                    sb.append("[all keyspaces]");
                else
                    sb.append('[').append(join(keyspaces, ", ")).append(']');

                if (!snapshotName.isEmpty())
                    sb.append(" with snapshot name [").append(snapshotName).append(']');

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