def dedup_alert(self, alert, history):
        """
        Update alert status, service, value, text, timeout and rawData, increment duplicate count and set
        repeat=True, and keep track of last receive id and time but don't append to history unless status changes.
        """
        query = {
            'environment': alert.environment,
            'resource': alert.resource,
            'event': alert.event,
            'severity': alert.severity,
            'customer': alert.customer
        }

        now = datetime.utcnow()
        update = {
            '$set': {
                'status': alert.status,
                'service': alert.service,
                'value': alert.value,
                'text': alert.text,
                'timeout': alert.timeout,
                'rawData': alert.raw_data,
                'repeat': True,
                'lastReceiveId': alert.id,
                'lastReceiveTime': now
            },
            '$addToSet': {'tags': {'$each': alert.tags}},
            '$inc': {'duplicateCount': 1}
        }

        # only update those attributes that are specifically defined
        attributes = {'attributes.' + k: v for k, v in alert.attributes.items()}
        update['$set'].update(attributes)

        if alert.update_time:
            update['$set']['updateTime'] = alert.update_time

        if history:
            update['$push'] = {
                'history': {
                    '$each': [history.serialize],
                    '$slice': -abs(current_app.config['HISTORY_LIMIT'])
                }
            }

        return self.get_db().alerts.find_one_and_update(
            query,
            update=update,
            return_document=ReturnDocument.AFTER
        )