dotnet/orleans · error · ArgumentException

Table name "{tableName}" is invalid according to the followi

Error message

Table name "{tableName}" is invalid according to the following rules: 1. Table names may contain only alphanumeric characters. 2. Table names cannot begin with a numeric character. 3. Table names must be from 3 to 63 characters long.

What it means

ArgumentException from AzureTableUtils.ValidateTableName when the table name does not match ^[A-Za-z][A-Za-z0-9]{2,62}$, the documented Azure Table Service naming rule. Names must be alphanumeric, start with a letter, and be 3-63 characters long. Validation runs at manager construction, so it surfaces before any storage I/O.

Source

Thrown at src/Azure/Shared/Storage/AzureTableUtils.cs:194

        public static bool IsNotFoundError(HttpStatusCode httpStatusCode)
        {
            // Status and Error Codes
            // http://msdn.microsoft.com/en-us/library/dd179382.aspx

            if (httpStatusCode == HttpStatusCode.NotFound) return true;
            if (httpStatusCode == HttpStatusCode.NotImplemented) return true; // New table: Azure table schema not yet initialized, so need to do first create
            return false;
        }

        [GeneratedRegex("^[A-Za-z][A-Za-z0-9]{2,62}$")]
        private static partial Regex TableNameRegex();

        internal static void ValidateTableName(string tableName)
        {
            // Regular expression from documentation: https://learn.microsoft.com/rest/api/storageservices/understanding-the-table-service-data-model#table-names
            if (!TableNameRegex().IsMatch(tableName))
            {
                throw new ArgumentException($"Table name \"{tableName}\" is invalid according to the following rules:"
                    + " 1. Table names may contain only alphanumeric characters."
                    + " 2. Table names cannot begin with a numeric character."
                    + " 3. Table names must be from 3 to 63 characters long.");
            }
        }

        /// <summary>
        /// Remove any characters that can't be used in Azure PartitionKey or RowKey values.
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public static string SanitizeTableProperty(string key)
        {
            // Remove any characters that can't be used in Azure PartitionKey or RowKey values
            // http://www.jamestharpe.com/web-development/azure-table-service-character-combinations-disallowed-in-partitionkey-rowkey/
            key = key
                .Replace('/', '_')        // Forward slash
                .Replace('\\', '_')       // Backslash

View on GitHub (pinned to fca799fa70)

Solutions

1. Sanitize your ServiceId/ClusterId so the resulting table name is alphanumeric and 3-63 chars, starting with a letter.
2. Provide a custom table-name policy or configure the relevant UseXxxAzureStorage().TableName to a valid literal.
3. Validate candidate names at startup with the same regex: Regex.IsMatch(name, @"^[A-Za-z][A-Za-z0-9]{2,62}$").

Example fix

// before
var tableName = $"{serviceId}-{clusterId}"; // '-' is illegal

// after
var tableName = Utils.SanitizeTableProperty($"{serviceId}{clusterId}");
// ensure length 3..63 and first char a letter; consider prefix 'o' if needed

if (!Regex.IsMatch(tableName, @"^[A-Za-z][A-Za-z0-9]{2,62}$"))
    throw new ArgumentException($"Invalid table name: {tableName}");
new AzureTableDataManager<T>(tableName, ...);

static bool IsValidTableName(string name) => Regex.IsMatch(name, @"^[A-Za-z][A-Za-z0-9]{2,62}$");

When it happens

Trigger: Constructing any AzureTableDataManager-derived manager (membership, reminders, grain directory, streaming, persistence) with a TableName containing illegal characters, starting with a digit, or being too short/long. The regex is source-generated.

Common situations: Deriving the table name from a ClusterId/ServiceId that contains hyphens, dots, or underscores; a ServiceId that is empty or 1-2 chars; using a lowercased/upper-cased variant that starts with a number; or a custom ITableNameProvider returning an invalid value.

Related errors

• Too many rows for bulk update - max {this.StoragePolicyOptio
• Key length {0} is too long to be an Azure table key. Key={1}
• Unknown Playground:Storage:Provider value '{storageProvider}
• The table version entry must have a membership version.
• Value cannot be null. (Parameter 'clusterId')

AI-assisted analysis of dotnet/orleans@fca799fa70 (2026-08-13). Data as JSON: /api/errors/eb6bb25a86e18222. Report an issue: GitHub.