apache/cassandra · error · IllegalArgumentException

Replication factor should not be set if previous operation i

Error message

Replication factor should not be set if previous operation is resumed

What it means

nodetool cms takes --resume to continue a previously interrupted CMS reconfiguration. execute() throws IllegalArgumentException when extra positional args (replication factors) are passed along with --resume, since a resumed operation already carries its own target RF.

Source

Thrown at src/java/org/apache/cassandra/tools/nodetool/CMSAdmin.java:150

        {
            if (status)
            {
                Map<String, List<String>> status = probe.getCMSOperationsProxy().reconfigureCMSStatus();
                if (status == null)
                {
                    output.out.println("No active reconfiguration");
                }
                else
                {
                    for (Map.Entry<String, List<String>> e : status.entrySet())
                        output.out.printf("%s: %s%n", e.getKey(), e.getValue());
                }
                return;
            }
            if (resume)
            {
                if (!args.isEmpty())
                    throw new IllegalArgumentException("Replication factor should not be set if previous operation is resumed");

                probe.getCMSOperationsProxy().resumeReconfigureCms();
                return;
            }

            if (cancel)
            {
                probe.getCMSOperationsProxy().cancelReconfigureCms();
                return;
            }

            if (args.isEmpty())
                throw new IllegalArgumentException("Replication factor is empty");

            Map<String, Integer> parsedRfs = new HashMap<>(args.size());
            for (String rf : args)
            {
                if (!rf.contains(":"))

View on GitHub (pinned to 88fd0f6a0e)

Solutions

1. Call 'nodetool cms --resume' with no positional args
2. If you want to change the RF, start a fresh reconfiguration with the RF args instead of resuming
3. Cancel the stuck reconfiguration first (cms --cancel), then invoke cms with the new RF

Example fix

// before
nodetool cms --resume 3
// after
nodetool cms --resume

if (resume && rfArgs.size() > 0)
    throw new IllegalArgumentException("--resume takes no RF arguments; omit them or start a fresh reconfigure");

When it happens

Trigger: Running 'nodetool cms --resume rf1=x' or 'nodetool cms --resume <dc>:3' — resume combined with any replication factor arguments.

Common situations: Script building a cms command with args always appended; operator resuming after editing the RF args expecting them to apply; copy-pasting a full 'cms --rf' command and adding --resume.

Related errors

• Replication factor is empty
• Simple placement can only specify a single replication facto
• Can not parse replication factor from %s
• Cannot combine -dc and -hosts options.
• You need to run primary range repair on all nodes in the clu

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/d353c946e17fb036. Report an issue: GitHub.