O aumento crescente no número de processadores das arquiteturas paralelas que estão no topo dos rankings de desempenho, apesar de permitir uma maior capacidade de processamento, também traz consigo um aumento na taxa de falhas diretamente proporcional ao número de processadores. Atualmente, as técnicas de tolerância a falhas com recuperação retroativa são as mais empregadas em aplicações MPI, principalmente a técnica de checkpoint coordenado. No entanto, previsões afirmam que essa última técnica será inadequada para as arquiteturas emergentes. Em contrapartida, as técnicas de log de mensagens possuem características que as tornam mais apropriadas no novo cenário que se estabelece. O presente trabalho consiste em uma proposta de log de mensagens pessimista remoto com checkpoint não-coordenado e a avaliação de desempenho da comunicação MPI sobre Publish/Subscriber no qual se baseia o log de mensagens. O trabalho compreende: um estudo das técnicas de tolerância a falhas mais empregadas em ambientes de alto desempenho e a motivação para a escolha dessa variante de log de mensagens; a proposta de log de mensagens; uma implementação de comunicação Open MPI sobre OpenAMQ e sua respectiva avaliação de desempenho com comunicação tradicional TCP/IP e com o log de mensagens pessimista local da distribuição do Open MPI. Os benchmarks utilizados foram o NetPIPE, o NAS Parallel Benchmarks e a aplicação Virginia Hydrodynamics (VH-1). / The growing number of processors in parallel architectures at the top of performance rankings allows a higher processing capacity. However, it also brings an increase in the fault rate which is directly proportional to the number of processors. Nowadays, coordinated checkpoint is the most widely used rollback technique for system recovery in the occurrence of faults in MPI applications. Nevertheless, projections point that this technique will be inappropriate for the emerging architectures. On the other hand, message logging seems to be more appropriate to this new scenario. This work consists in a proposal of pessimistic message logging (remote based) with non-coordinated checkpoint and the performance evaluation of an MPI communication mechanism that works over Publish/Subscriber channels in which the proposed message logging is based. The work is organized as following: an study of fault tolerant techniques used in HPC and the motivation for choosing this variant of message logging; a message logging proposal; an implementation of Open MPI communication over OpenAMQ; performance evaluation and comparision with the tradicional TCP/IP communication and a pessimistic message logging (sender based) from Open MPI distribution. The benchmark set is composed of NetPIPE, NAS Parallel Benchmarks and Virginia Hydrodynamics (VH-1).

Many different message-oriented middlewares (MOM) exist today on the market. With different underlying designs, purposes and features, it is not easy to make the right choice of MOM for your system. The IT company Nordicstation is in such a situation where they need to make a choice of MOM. They currently own a system called Sharelock which generates reports about violations of financial assets trad- ing. They wish to make the process of generating a report more asynchronous by using a MOM and they have a couple of requirements. This thesis was carried out with the purpose of finding the most suitable products for the system in mind, compare their features, performance, licenses and ease-of- use. This was accomplished by analysing their installation process, monitoring in- terfaces, documentation on their websites and performance in a simple throughput test. The results showed that RabbitMQ was the strongest candidate. It had good per- formance, an attractive web interface for monitoring, an easy installation and it also offered commercial support. Apache Artemis was also found to be an attractive choice but it did not have a web interface which made it hard to manage the system. / Idag finns det många meddelandebaserade mellanprogramvaror (MOM) på marknaden. Dessa har olika grundläggande designer, syften och kännetecken vilket kan göra det svårt att göra ett bra val av MOM för ett visst system. IT-företaget Nordicstation befinner sig i en sådan situation där de behöver göra ett val av MOM. De har ett system som kallas Sharelock som genererar rapporter om regelbrott in- om värdepappershandeln. De vill göra processen mer asynkron genom att använda en MOM och de har ett antal krav på produkten. Det här examensarbetet utfördes med syftet att hitta de mest passande produkter- na för det tänka systemet, jämföra deras särdrag, prestanda, licenser och anvä- ndarvänlighet. Detta gjordes genom att analysera deras installationsprocess, övervakningsgränssnitt, dokumentation på deras hemsida och prestanda i ett en- kelt prestandatest. Resultaten visade att RabbitMQ var den starkaste kandidaten. Den hade bra prestanda, ett attraktivt webbgränssnitt, en enkel installation och den erbjöd också kommersiell support åt kunder. Apache Artemis var också ett attraktivt val men den hade inget webbgränssnitt vilket gjorde det svårt att övervaka och hantera sys- temet.

Distributed simulations require efficient communication to represent complex scenarios, which presents a great challenge. This paper investigates the use of message-oriented middleware (MOM) to address this challenge by integrating the flight simulator X-Plane with the tactical simulator TACSI and evaluating the performance of different data transfer approaches. The study assesses performance by measuring the maximum sustainable throughput (MST) and the latency of a publish-subscribe-based MOM system. Two data distribution methods are compared: single-topic publishing and publishing to multiple subtopics. The results show that single-topic publishing achieves higher MST and lower latency when transmitting the same data volume. These findings provide valuable insights for deciding the state distribution method for publish-subscribe MOM systems. Additionally, this study highlights the limitations of manual determination of MST and underlines the need for accurate performance measurement techniques. / Distribuerade system kräver effektiv kommunikation för att representera komplexa scenarion, vilket utgör en betydande utmaning. Denna rapport använder meddelandeorienterad mellanprogramvara (MOM) för att angripa denna utmaning genom att integrera flygsimulatorn X-Plane med den taktiska simulatorn TACSI och sedan utvärdera prestandan av olika dataöverföringsmetoder. Studien utvärderar prestandan genom att mäta den maximala genomströmningskapaciteten och latensen på ett publish-subscribe-baserat MOM-system. Två dataöverföringsmetoder jämförs: single-topic publicering och publicering på flera subtopics. Resultatet visar att single-topic publicering ger högre maximal genomströmningskapacitet och lägre latens vid samma mängd data. Dessa upptäckter ger värdefulla insikter när man ska bestämma metod för dataöverföring i publish-subscribe-baserade MOM-system. Slutligen visar denna studie på begränsningarna med att manuellt bestämma MST och behovet av mer noggranna tekniker för att mäta maximal genomströmningskapacitet.

Message-oriented middleware (MOM) is a middleware used for communication between applications. There are many different MOM technologies available today, each offering different performance (throughput and latency). The performance of MOMs depends on both message size and message guarantee settings used. The problem is that it can be difficult for users to know which MOM they should choose given their requirements. The goal was to create a performance (latency and throughput) comparison of three popular MOMs; Apache Kafka, RabbitMQ and Nats Streaming. The result shows that Kafka is the best performing MOM for smaller message sizes (under 512 bytes). RabbitMQ has the best performance for larger message sizes (over 32768 bytes). Nats Streaming only outperformed the other message system for a few combinations of message guarantee settings with the message size 4096 bytes. / Meddelandeorienterad mellanprogramvara (MOM) är mellanprogramvara som används för kommunikation mellan applikationer. Det finns många MOM system som erbjuder olika prestanda (genomströmning och latens). Prestandan är beroende av vilka meddelandegarantier som används samt meddelande storlek. Detta gör det svårt för användare att välja MOM utifrån sina krav. Målet är därför att jämföra tre populära MOMs; Apache Kafka, RabbitMQ och Nats Streaming. Resultaten visar att Kafka presterar bäst med små meddelandestorlekar (Under 512 bytes). RabbitMQ presterar bäst för större meddelanden (Över 32768 bytes) medans Nats Streaming enbart presterar bäst med ett begränsat antal meddelandegarantier och med en meddelandestorlek på 4096 bytes.

This thesis addresses a multi-phase research and development project that spanned nearly four years, targeted at providing an ultra high-efficiency, user-friendly, and economic intelligent lighting solution for commercial facility applications, initially targeting underground parking specifically. The system would leverage the strengths of four key technologies: high brightness white Light Emitting Diodes (LEDs), wireless sensor and actuator networks, single board computers, and cloud computing. An introduction to these technologies and an overview of how they were combined to build an intelligent lighting solution is given, followed by an in-depth description of the design and implementation of one of the main subsystems – the Sensor Middleware System – residing on a single board computer. Newly-available LED luminaires (a.k.a. light fixtures) bring the combination of high efficiency, reliability, illumination quality, and long-lifetime to the lighting market. Emerging low-power – and recently low-cost – 802.15.4 wireless networks offer high controllability and responsiveness to deployed luminaires and sensors. The cost- associativity, low maintenance, and easy build-up of Internet Data Center “cloud” computing resources make data collection and remote management infrastructure for Building Automation Systems accessible to even small companies. Additionally, these resources can be much more appropriately sized and allocated, which reduces energy use. These technologies are combined to form an Intelligent Lighting System (ILS). Fitting well within the Internet of Things paradigm, this highly distributed messaging-based “system of systems” was designed to be reliable through loose coupling – spanning multiple network layers and messaging protocols. Its goal was to deliver significant energy savings over incumbent technologies, configurable and responsive lighting service behaviour, and improved experience for users within the facility (pedestrians and drivers) and those interacting with its web-based tools (building managers and ILS administrators). The ILS was partitioned into three main subsystems as follows. The installed Wireless Field Network (WFN) of luminaires and sensors provided coordinated scheduled and real-time output level adjustment (i.e. dimming), with the help of motion sensor triggers. The Monitoring and Configuration System (MCS) in the cloud provided remote data collection and a web-based monitoring and configuration Graphical User Interface application. Network hardware and Message-Oriented Middleware (MOM) were responsible for tying these subsystems together. The MOM layer that provided the message brokering, translating, envelope wrapping, and guaranteed delivery services between the WFN and MCS, as well as field supervisory and quality-of-service functions for the WFN, was called the Sensor Middleware System (SMS). It was hosted on a single board computer located at the facility. / Graduate

Message Oriented Middleware (MOM) is an enabling technology for modern event- driven applications that are typically based on publish/subscribe communication [Eugster03]. Enterprises typically contain hundreds of applications operating in environments with diverse databases and operating systems. Integration of these applications is required to coordinate the business process. Unfortunately, this is no easy task. Enterprise Integration, according to Brosey et al. (2001), "aims to connect and combines people, processes, systems, and technologies to ensure that the right people and the right processes have the right information and the right resources at the right time"[Brosey01]. Communication between different applications can be achieved by using synchronous and asynchronous communication tools. In synchronous communication, both parties involved must be online (for example, a telephone call), whereas in asynchronous communication, only one member needs to be online (email). Middleware is software that helps two applications communicate with one another. Remote Procedure Calls (RPC) and Object Request Brokers (ORB) are two types of synchronous middleware—when they send a request they must wait for an immediate reply. This can decrease an application’s performance when there is no need for synchronous communication. Even though asynchronous distributed messaging using message oriented middleware is widely used in industry, there is not enough work done in evaluating the performance of various open source Message oriented middleware. The objective of this work was to benchmark and evaluate three different open source MOM’s performance in publish/subscribe and point-to-point domains, functional comparison and qualitative study from developers perspective.

Historically, the United States (US) electric grid has been a stable one-way power delivery infrastructure that supplies centrally-generated electricity to its predictably consuming demand. However, the US electric grid is now undergoing a huge transformation from a simple and static system to a complex and dynamic network, which is starting to interconnect intermittent distributed energy resources (DERs), portable electric vehicles (EVs), and load-altering home automation devices, that create bidirectional power flow or stochastic load behavior. In order for this grid of the future to effectively embrace the high penetration of these disruptive and fast-responding digital technologies without compromising its safety, reliability, and affordability, plug-and-play interoperability within the field area network must be enabled between operational technology (OT), information technology (IT), and telecommunication assets in order to seamlessly and securely integrate into the electric utility's operations and planning systems in a modular, flexible, and scalable fashion. This research proposes a potential approach to simplifying the translation and contextualization of operational data on the electric grid without being routed to the utility datacenter for a control decision. This methodology integrates modern software technology from other industries, along with utility industry-standard semantic models, to overcome information siloes and enable interoperability. By leveraging industrial engineering tools, a framework is also developed to help devise a reference architecture and use-case application process that is applied and validated at a US electric utility.