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Businesses often use mobile text messages (SMS) as a cost effective and universal way of communicating concise information to their customers. Today, these messages are usually sent via SMS brokers, which forward them further to the next stakeholder, typically the various mobile operators, and then the messages eventually reach the intended recipients. Infoflex Connect AB delivers an SMS gateway application to the brokers with the main responsibility of reliable message delivery within set quality thresholds. However, the protocols used for SMS communication are not designed for reliability and thus messages may be lost. In this position paper we deduce requirements for a new protocol for routing messages through the SMS gateway application running at a set of broker nodes, in order to increase the reliability. The requirements cover important topics for the required communication protocol such as event ordering, message handling and system membership. The specification of such requirements sets the foundation for the forthcoming design and implementation of such a protocol and its evaluation.

Mobile text messages (SMS) are sometimes used for authentication, which requires short and reliable delivery times. The observed round-trip times when sending an SMS message provide valuable information on the quality of the connection. In this industry paper, we propose a method for detecting round-trip time anomalies, where the exact distribution is unknown, the variance is several orders of magnitude, and there are lots of shorter spikes that should be ignored. In particular, we show that using an adaption of Double Seasonal Exponential Smoothing to reduce the content dependent variations, followed by the Remedian to find short-term and long-term medians, successfully identifies larger groups of outliers. As training data for our method we use log files from a live SMS gateway. In order to verify the effectiveness of our approach, we utilize simulated data. Our contributions are a description on how to isolate content dependent variations, and the sequence of steps to find significant anomalies in big data.

To keep internet based services available despite inevitable local internet and power outages, their data must be replicated to one or more other sites. For most systems using the store-and-forward architecture, data loss can also be prevented by using end-to-end acknowledgements. So far we have not found any sufficiently good solutions for replication of data in store-and-forward systems without acknowledgements and with geographically separated system nodes. We therefore designed a new replication protocol, which could take advantage of the lack of a global order between the messages and the acceptance of a slightly higher risk for duplicated deliveries than existing protocols. We tested a proof-of-concept implementation of the protocol for throughput and latency in a controlled experiment using 7 nodes in 4 geographically separated areas, and observed the throughput increasing superlinearly with the number of nodes up to almost 3500 messages per second. It is also, to the best of our knowledge, the first replication protocol with a bandwidth usage that scales according to the number of nodes allowed to fail and not the total number of nodes in the system.

Background: The Enterprise Messaging Gateway(EMG) from Infoflex Connect (ICAB) is a monolithic system used to deliver mobile text messages (SMS) world-wide. The companies using it have diverse requirements on both functionality and quality attributes and would thus benefit from more versatile customizations, e.g. regarding authorization and data replication.

Objective: ICAB needed help in assessing the current architecture of EMG in order to find candidates for architectural changes as well as fulfilling the needs of variability in meeting the wide range of customer requirements.

Method: We analysed EMG using a lightweight version of ATAM (Architectural Trade-off Analysis Method) to get a better understanding of how different architectural decisions would affect the trade-offs between the quality requirements from the identified stakeholders.

Result: Using the results of this structured approach, it was easy for ICAB to identify the functionality that needed to be improved. It also became clear that the selected component should be converted into a set of microservices, each one optimized for a specific set of customers.

Limitation: The stakeholder requirements were gathered intermittently during a long period of continuous engagement, but there is a chance some of their requirements were still not communicated to us.

Conclusion: Even though this ATAM study was performed internally at ICAB without direct involvement from any external stakeholders, documenting elicited quality attribute requirements and relating them to the EMG architecture provided new, unexpected, and valuable understandings of the system with a rather small effort.