apache/cassandra · error · RuntimeException

Error setting log for on level . Please check logback confi

Error message

Error setting log for  on level . Please check logback configuration.

What it means

NodeProbe wraps any exception thrown while changing a class's logging level via the StorageService JMX MBean (ssProxy.setLoggingLevel) into a RuntimeException. This means the requested class qualifier or log level was rejected by the server-side logback configuration, or the JMX call itself failed. The original cause is attached as the exception cause.

Source

Thrown at src/java/org/apache/cassandra/tools/NodeProbe.java:2423

    public TabularData getCompactionHistory()
    {
        return compactionProxy.getCompactionHistory();
    }

    public void reloadTriggers()
    {
        spProxy.reloadTriggerClasses();
    }

    public void setLoggingLevel(String classQualifier, String level)
    {
        try
        {
            ssProxy.setLoggingLevel(classQualifier, level);
        }
        catch (Exception e)
        {
            throw new RuntimeException("Error setting log for " + classQualifier + " on level " + level + ". Please check logback configuration.", e);
        }
    }

    public Map<String, String> getLoggingLevels()
    {
        return ssProxy.getLoggingLevels();
    }

    public long getPid()
    {
        return NativeLibrary.getProcessID();
    }

    public void resumeBootstrap(PrintStream out) throws IOException
    {
        BootstrapMonitor monitor = new BootstrapMonitor(out);
        try
        {

View on GitHub (pinned to 88fd0f6a0e)

Solutions

1. Verify the class qualifier matches a real logger name (fully-qualified class or package), e.g. org.apache.cassandra.db.
2. Use a valid logback level: DEBUG, TRACE, INFO, WARN, or ERROR (VERBOSITY is a log4j-era level).
3. Inspect the exception cause (`nodetool` output or server log) to see the underlying logback error.
4. Confirm JMX connectivity (nodetool status works) and that logback.xml is valid on the node.

Example fix

// before
nodetool setlogginglevel org.apache.cassandra.db.Bootstrap VERBOSITY
// after
nodetool setlogginglevel org.apache.cassandra.db DEBUG

Set<String> valid = Set.of("TRACE","DEBUG","INFO","WARN","ERROR");
if (!valid.contains(level.toUpperCase())) throw new IllegalArgumentException("Invalid log level: " + level);
if (!classQualifier.matches("[a-zA-Z0-9_.]+")) throw new IllegalArgumentException("Invalid logger class: " + classQualifier);

try { probe.setLoggingLevel(cls, level); }
catch (RuntimeException e) { logger.error("setLoggingLevel failed for {} at {}: {}", cls, level, e.getCause(), e); }

When it happens

Trigger: Calling `nodetool setlogginglevel <class> <level>` (or NodeProbe.setLoggingLevel) with a class name that does not exist, a level that is not a valid logback level (TRACE/DEBUG/INFO/WARN/ERROR), or when the JMX connection fails mid-call.

Common situations: Typo in the logger class/package name; using a custom level like VERBOSITY with logback (which no longer accepts it, unlike log4j); logback reconfiguration errors on the node; stale JMX connection.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• Error while refreshing system.size_estimates
• Unknown Cache metric name
• Unknown BufferPool metric name
• throw new IOException(e)
• Argument must have keyspace and table values.

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/d942f8184e93b5e9. Report an issue: GitHub.