nicolargo/glances · warning · ValueError

replication_factor must be a positive integer

Error message

replication_factor must be a positive integer

What it means

The Cassandra export requires replication_factor to parse as an int >= 1; anything else (0, negative, non-numeric string) raises this ValueError, which is caught in the same __init__, logged as 'Cassandra configuration error', and results in the export being disabled (export_enable = False). Glances itself continues to run.

Source

Thrown at glances/exports/glances_cassandra/__init__.py:69

        self.username = None
        self.password = None

        # Load the Cassandra configuration file section
        self.export_enable = self.load_conf(
            'cassandra',
            mandatories=['host', 'port', 'keyspace'],
            options=['protocol_version', 'replication_factor', 'table', 'username', 'password'],
        )
        if not self.export_enable:
            sys.exit(2)

        # Validate CQL identifiers to prevent injection via config values
        try:
            self.keyspace = _validate_cql_identifier(self.keyspace, 'keyspace')
            self.table = _validate_cql_identifier(self.table, 'table')
            self.replication_factor = int(self.replication_factor)
            if self.replication_factor < 1:
                raise ValueError("replication_factor must be a positive integer")
        except ValueError as e:
            logger.error(f"Cassandra configuration error: {e}")
            self.export_enable = False
            return

        # Init the Cassandra client
        self.cluster, self.session = self.init()

    def init(self):
        """Init the connection to the Cassandra server."""
        if not self.export_enable:
            return None

        # if username and/or password are not set the connection will try to connect with no auth
        auth_provider = PlainTextAuthProvider(username=self.username, password=self.password)

        # Cluster
        try:

View on GitHub (pinned to a240d8dfb3)

Solutions

1. Set a positive integer, e.g. export_cassandra_replication_factor=1 (or 3 for production clusters).
2. Verify the key in glances.conf is spelled export_cassandra_replication_factor and holds a bare integer.
3. Check glances.log for 'Cassandra configuration error' to confirm validation failed and the export was disabled.

Example fix

# before
[export_cassandra]
replication_factor=0

# after
[export_cassandra]
replication_factor=1

rf = int(config.get('replication_factor', 1))
assert rf >= 1, 'replication_factor must be >= 1'

def is_valid_replication_factor(v) -> bool:
    try:
        return int(v) >= 1
    except (TypeError, ValueError):
        return False

When it happens

Trigger: Setting export_cassandra_replication_factor to 0, -1, 'two', or omitting a default that resolves falsy in glances.conf. Also triggered if the config value has stray whitespace or quotes that break int().

Common situations: Single-node test clusters where users set replication_factor=0 thinking it means 'no replication'; config typos like replication_factor = 1; environments with more than one datacenter but a simple-int config.

Related errors

• Invalid CQL identifier for '{name}': {value!r}. Only letters

AI-assisted analysis of nicolargo/glances@a240d8dfb3 (2026-08-27). Data as JSON: /api/errors/6cae6c85ae2c9adf. Report an issue: GitHub.