human
Complete this python program:
def OperationRetriesCriteria(operation_rate, retry_rate):
assistant
#Here is the Python program you requested.

    """Monitor the rate of operation retries on the server.  The number of operation retries
    will be compared to the total number of operations run.
    """
    alerts = []
    warnings = []
    def _ComputeThreshold(x):
        return (math.ceil(math.sqrt(x)) / 3)
    if (retry_rate['cluster_total'] > _ComputeThreshold(operation_rate['cluster_total'])):
        warnings.append(CLUSTER_TOKEN)
    for (m, v) in operation_rate['machine_data'].iteritems():
        if (retry_rate['machine_data'][m] > _ComputeThreshold(v)):
            warnings.append(m)
    return (alerts, warnings)