This is a bachelor thesis regarding the performance differences for hosting a web-application in a virtualized environment. We compare virtual machines against containers and observe their resource usage in categories such as CPU, RAM and disk storage in idle state and perform a range of computation experiments in which response times are measured from a series of request intervals. Response times are measured with the help of a web-application created in Python. The experiments are performed under both normal and stressed conditions to give a better indication in to which virtualized environment outperform the other during different scenarios. The results show that virtual machines and containers remained close to each other in response times during the first request interval, but the containers outperformed virtual machines in terms of resource usages while in idle state, they had less of a burden on the host computer. They were also significantly more rapid in terms of response times. This is also most noticeable during stressed conditions in which the virtual machine almost doubled its sluggishness.

No description available.

As chip vendors are increasingly manufacturing a new generation of multi-processor chips called multicores, improving software performance requires exposing greater concurrency in software. Since code that must be run sequentially is often due to the need for synchronization, the synchronization abstraction has a significant effect on program performance. Lock-based synchronization — the most widely used synchronization method — suffers from programability, scalability, and composability challenges. Transactional memory (TM) is an emerging synchronization abstraction that promises to alleviate the difficulties with lock-based synchronization. With TM, code that read/write shared memory objects is organized as transactions, which speculatively execute. When two transactions conflict (e.g., read/write, write/write), one of them is aborted, while the other commits, yielding (the illusion of) atomicity. Aborted transactions are re-started, after rolling-back changes made to objects. In addition to a simple programming model, TM provides performance comparable to lock-based synchronization. Software transactional memory (STM) implements TM entirely in software, without any special hardware support, and is usually implemented as a library, or supported by a compiler or by a virtual machine. In this thesis, we present ByteSTM, a virtual machine-level Java STM implementation. ByteSTM implements two STM algorithms, TL2 and RingSTM, and transparently supports implicit transactions. Program bytecode is automatically modified to support transactions: memory load/store bytecode instructions automatically switch to transactional mode when a transaction starts, and switch back to normal mode when the transaction successfully commits. Being implemented at the VM-level, it accesses memory directly and uses absolute memory addresses to uniformly handle memory. Moreover, it avoids Java garbage collection (which has a negative impact on STM performance), by manually allocating and recycling memory for transactional metadata. ByteSTM uses field-based granularity, and uses the thread header to store transactional metadata, instead of the slower Java ThreadLocal abstraction. We conducted experimental studies comparing ByteSTM with other state-of-the-art Java STMs including Deuce, ObjectFabric, Multiverse, DSTM2, and JVSTM on a set of micro- benchmarks and macro-benchmarks. Our results reveal that, ByteSTM's transactional throughput improvement over competitors ranges from 20% to 75% on micro-benchmarks and from 36% to 100% on macro-benchmarks. / Master of Science

Cette thèse présente deux contributions. La première contribution consiste en l’étude des métriques de performance permettant de superviser l’activité des serveurs physiques et des machines virtuelles s’exécutant sur les hyperviseurs VMware et KVM. Cette étude met en avant les compteurs clés et propose des analyses avancées dans l’objectif de détecter ou prévenir d’anomalies liées aux quatreres sources principales d’un centre de données : le processeur, la mémoire, le disque et le réseau. La seconde contribution porte sur un outil pour la détection de machines virtuelles à comportements pré-déterminés et/ou atypiques. La détection de ces machines virtuelles à plusieurs objectifs. Le premier, permettre d’optimiser l’utilisation des ressources matérielles en libérant des ressources par la suppression de machines virtuelles inutiles ou en les redimensionnant. Le second, optimiser le fonctionnement de l’infrastructure en détectant les machines sous-dimensionnées, surchargées ou ayant une activité différente des autres machines virtuelles de l’infrastructure. / This thesis presents two contributions. The first contribution is the study of key performance indicators to monitor physical and virtual machines activity running on VMware and KVM hypervisors. This study highlights performance metrics and provides advanced analysis with the aim to prevent or detect abnormalities related to the four main resources of a datacenter: CPU, memory, disk and network. Thesecond contribution relates to a tool for virtual machines with pre-determined and / or atypical behaviors detection. The detection of these virtual machines has several objectives. First, optimize the use of hardware resources by freeing up resources by removing unnecessary virtual machines or by resizing those oversized. Second, optimize infrastructure performance by detecting undersized or overworked virtual machines and those having an atypical activity.

In the context of cloud computing, Trusted Execution Environments (TEE) are isolated areas of application software that can be executed with better security, building a trusted and secure environment that is detached from the rest of the memory. Trusted Execution Environment is a technology that become available only in the last few years, and it is not widespread yet. This thesis investigates the most popular approaches to build a TEE, namely the process-based and the virtualization-based, and will abstract them as much as possible to design a common infrastructure that can deploy TEEs on an external cloud provider, no matter which technology approach is used. The thesis is relevant and novel because the project will give the possibility to use different technologies for the deployment, such as Intel SGX and AMD SEV, which are the two main solutions, but without being reliant on any particular one. If in the future new technologies or vendors’ solutions will become popular, they can be simply added to the list of options. The same can be said for the cloud provider choice. The results show that it is possible to abstract the common features of different TEE’s technologies and to use a unique Application Programming Interface (API) to deploy different TEE´s technologies. We will also ran a performance and quality evaluation, and the results show that the API is performant and respect the common standard quality. This tool is useful for the problem owner and future works on the topic of cloud security. / I samband med cloud computing är Trusted Execution Environments (TEE) isolerade områden av applikationsprogramvara som kan köras med bättre säkerhet, bygga en pålitlig och säker miljö som är frikopplad från resten av minnet. Trusted Execution Environment är en teknik som blivit tillgänglig först under de senaste åren, och den är inte utbredd ännu. Denna avhandling undersöker de mest populära metoderna för att bygga en TEE, nämligen den processbaserade och den virtualiseringsbaserade, och kommer att abstrahera dem så mycket som möjligt för att designa en gemensam infrastruktur som kan distribuera TEEs på en extern molnleverantör, oavsett vilken teknik tillvägagångssätt används. Avhandlingen är relevant och ny eftersom projektet kommer att ge möjligheten att använda olika teknologier för implementeringen, såsom Intel SGX och AMD SEV, som är de två huvudlösningarna, men utan att vara beroende av någon speciell. Om i framtiden nya teknologier eller leverantörers lösningar kommer att bli populära kan de helt enkelt läggas till i listan över alternativ. Detsamma kan sägas om valet av molnleverantör. Resultaten visar att det är möjligt att abstrahera de gemensamma egenskaperna hos olika TEE:s teknologier och att använda ett unikt Application Programming Interface (API) för att distribuera olika TEE:s teknologier. Vi kommer också att göra en prestanda- och kvalitetsutvärdering, och resultaten visar att API:et är prestanda och respekterar den gemensamma standardkvaliteten. Det här verktyget är användbart för problemägaren och framtida arbeten på ämnet molnsäkerhet.

The growth of networks around the world has also given rise to threats like viruses and Trojans. This rise in threats has resulted in counter measures for these threats. These counter measures are in the form of applications called firewalls or IDS. The incorporation of these applications in the network results in some delay in communications. The aim of the experiment in this thesis is to measure the delay introduced by such a firewall in the best case and compare it with the communication done on a network without such an application. These experiments are done using a special miniature computer called the net4801 with an embedded operating system and the packet scanning application (firewall or IDS) executing on it.

Avec l’émergence de l’informatique dans les nuages, la capacité d’hébergement des centres de données ne cesse d’augmenter afin de répondre à une demande de plus en plus forte. La gestion, appelée l’administration, d’un centre de données entraîne des opérations fréquentes sur des machines virtuelles (VM) ainsi que sur des serveurs. De plus, chaque VM hébergée possède des besoins spécifiques au regard de sa qualité de service, de ses ressources et de son placement qui doit être compatible avec les mécanismes de tolérance aux pannes et la configuration réseau. Les outils de « l’Infrastructure As A Service » tels que Open Nebula et Vmware vSphere simplifient la création et le déploiement de VM. Cependant, l’administration d’une infrastructure virtualisée repose encore sur des changements manuels décidés par les administrateurs. Cette approche n’est plus pertinente pour la gestion d’infrastructures virtualisées de milliers de VM. En effet, les administrateurs ne peuvent pas manipuler des ensembles importants de VM tout en assurant la compatibilité des reconfigurations exécutées avec les besoins des VM. De nouvelles approches d’administration d’infrastructures proposent l’automatisation de certaines tâches d’administration. L’outil décrit dans ce document utilise des langages dédiés pour répondre aux besoins d’administration infrastructures virtualisées de taille conséquente. Dans un premier temps, l’outil propose aux administrateurs des opérations d’introspection pour observer l’organisation des ressources déployées sur l’infrastructure et les reconfigurations habituelles comme le démarrage, l’arrêt et le redémarrage de VM et de serveurs. Dans un second temps les administrateurs définissent le placement des VM à partir de règles de placement. À partir de ces règles, l’outil d’administration vérifie chaque reconfiguration et chaque ajout de règles exécutés par l’administrateur. Si une reconfiguration ou une règle est invalide, l’outil détecte un conflit et avertit l’administrateur de l’échec de l’opération. L’outil d’administration, à l’aide d’algorithmes d’ordonnancement peut calculer un plan de reconfigurations résolvant les conflits. Ces algorithmes peuvent aussi être utilisés pour mettre en place des politiques d’ordonnancement comme la consolidation ou l’équilibrage de charge. / With the emergence of cloud computing, the hosting capacity of the data centers has been continuously growing to support the non stop increasing clients demand. Managing a data center implies to regularly manipulate both virtual machines (VM) and servers. Each hosted VM has specific expectations regarding its quality of service, its resource requirements and its placement that may be compatible with fault tolerance mechanisms and the networking configuration. Infrastructure As A Service solutions such as Open Nebula and VMWare vSphere extremely simplify creations and deployments of VM but virtualized infrastructure management is still relying on manual changes on the environment. This approach is no longer compatible with an infrastructure composed of thousand of VM. Indeed, a system administrator can not manipulate a large set of VMinsuring that its reconfigurations are compatible with the expected VM requirements. This situation has led to new approaches for the infrastructure management employing automation to replace the traditional manual approach. The tool described in this document deals with VM management from Domain Specific Languages. On the one hand, this tool proposes to administrators introspection operations to monitor the infrastructure resources and common reconfigurations including starting, halting, rebooting, of serversand VM. On the other hand, administrators define the VM placement from placement rules. Then, the system checks, according to active rules, the validity of all reconfigurations and rules performed by administrators. If a reconfiguration or a rule is invalid, the administrative tool detects conflicts and warns administrators. To resolve a conflict, the system, by interacting with scheduling algorithms, computes a reconfiguration plan that satisfies all rules.The reconfiguration plan can also apply scheduling policies as consolidation or load balancing with respect to placement rules.

As Máquinas Virtuais ganharam grande importância com o advento de processadores multi-core (na plataforma x86) e com o barateamento de componentes de hardware, como a memória. Por conta desse substancial aumento do poder computacional, surgiu o desafio de tirar proveito dos recursos ociosos encontrados nos ambientes corporativos, cada vez mais populados por equipamentos multi-core e com vários Gigabytes de memória. A virtualização, mesmo sendo um conceito já antigo, tornou-se novamente popular neste cenário, pois com ela foi possível utilizar melhor os recursos computacionais, agora abundantes. Este trabalho tem como principal foco estudar algumas das principais técnicas de gerência de recursos computacionais em ambientes virtualizados. Apesar de muitos dos conceitos aplicados nos projetos de Monitores de Máquinas Virtuais terem sido portados de Sistemas Operacionais convencionais com pouca, ou nenhuma, alteração; alguns dos recursos ainda são difíceis de virtualizar com eficiência devido a paradigmas herdados desses mesmos Sistemas Operacionais. Por fim, é apresentado o Memory Dispatcher (MD), um mecanismo de gerenciamento de memória, com o objetivo principal de distribuir a memória entre as Máquinas Virtuais de modo mais eficaz. Este mecanismo, implementado em C, foi testado no Monitor de Máquinas Virtuais Xen e apresentou ganhos de memória de até 70%. / Virtual Machines have gained great importance with advent of multi-core processors (on platform x86) and with low cost of hardware parts, like physical memory. Due to this computational power improvement a new challenge to take advantage of idle resources has been created. The virtualization technology, even being an old concept became popular in research centers and corporations. With this technology idle resources now can be exploited. This work has the objective to show the main techniques to manage computational resources in virtual environments. Although many of current concepts used in Virtual Machine Monitors project has been ported, with minimal changes, from conventional Operating Systems there are some resources that are difficult to virtualize with efficiency due to old paradigms still present in Operating Systems projects. Finally, the Memory Dispatcher (MD) is presented, a mechanism used to memory management. The main objective of MD is to improve the memory share among Virtual Machines. This mechanism was developed in C and it was tested in Xen Virtual Machine Monitor. The MD showed memory gains up to 70%.

Cette thèse traite des langages à objets en héritage multiple et typage statique exécutés avec des machines virtuelles. Des analogies sont à faire avec Java bien que ce langage ne soit pas en héritage multiple.Une machine virtuelle est un système d'exécution d'un programme qui se différencie des classiques compilateurs et interpréteurs par une caractéristique fondamentale : le chargement dynamique. Les classes sont alors découvertes au fil de l'exécution.Le but de la thèse est d'étudier et de spécifier une machine virtuelle pour un langage à objets en héritage multiple, pour ensuite spécifier et implémenter des protocoles de compilation/recompilation. Ces derniers devront mettre en place les optimisations et les inévitables mécanismes de réparations associés.Nous présenterons d'abord l'architecture et les choix réalisés pour implémenter la machine virtuelle : ceux-ci utilisent le langage Nit en tant que langage source ainsi que le hachage parfait, une technique d'implémentation de l'héritage multiple.Ensuite nous présenterons les spécifications pour implémenter des protocoles de compilation/recompilation ainsi que les expérimentations associées.Dans ce cadre, nous avons présenté une extension des analyses de préexistence et de types concrets, pour augmenter les opportunités d'optimisations sans risque. Cette contribution dépasse la problématique de l'héritage multiple. / This thesis is about object-oriented languages in multiple inheritance and static typing executed by virtual machines.We are in the context of a Java-like language and system but in multiple inheritance.A virtual machine is an execution system which is different from static compilers and interpreters since they are in dynamic loading.This characteristic makes classes to be discovered during the execution.The thesis' goal is to study, specify and implement a virtual machine for an object-oriented language in multiple inheritance and then in a second step to specify and implement compilation/recompilation protocols.These protocols are in charge of optimizations and unavoidable repairing.We will present the architecture of the virtual machine : the used language is Nit, and perfect hashing as the multiple inheritance implementation technique. Then we will present the protocols and the experiments.In this thesis, we have presented an extension of preexistence and concrete types analysis to increase optimization opportunities. This contribution is not limited to multiple inheritance object-oriented languages.

As Máquinas Virtuais ganharam grande importância com o advento de processadores multi-core (na plataforma x86) e com o barateamento de componentes de hardware, como a memória. Por conta desse substancial aumento do poder computacional, surgiu o desafio de tirar proveito dos recursos ociosos encontrados nos ambientes corporativos, cada vez mais populados por equipamentos multi-core e com vários Gigabytes de memória. A virtualização, mesmo sendo um conceito já antigo, tornou-se novamente popular neste cenário, pois com ela foi possível utilizar melhor os recursos computacionais, agora abundantes. Este trabalho tem como principal foco estudar algumas das principais técnicas de gerência de recursos computacionais em ambientes virtualizados. Apesar de muitos dos conceitos aplicados nos projetos de Monitores de Máquinas Virtuais terem sido portados de Sistemas Operacionais convencionais com pouca, ou nenhuma, alteração; alguns dos recursos ainda são difíceis de virtualizar com eficiência devido a paradigmas herdados desses mesmos Sistemas Operacionais. Por fim, é apresentado o Memory Dispatcher (MD), um mecanismo de gerenciamento de memória, com o objetivo principal de distribuir a memória entre as Máquinas Virtuais de modo mais eficaz. Este mecanismo, implementado em C, foi testado no Monitor de Máquinas Virtuais Xen e apresentou ganhos de memória de até 70%. / Virtual Machines have gained great importance with advent of multi-core processors (on platform x86) and with low cost of hardware parts, like physical memory. Due to this computational power improvement a new challenge to take advantage of idle resources has been created. The virtualization technology, even being an old concept became popular in research centers and corporations. With this technology idle resources now can be exploited. This work has the objective to show the main techniques to manage computational resources in virtual environments. Although many of current concepts used in Virtual Machine Monitors project has been ported, with minimal changes, from conventional Operating Systems there are some resources that are difficult to virtualize with efficiency due to old paradigms still present in Operating Systems projects. Finally, the Memory Dispatcher (MD) is presented, a mechanism used to memory management. The main objective of MD is to improve the memory share among Virtual Machines. This mechanism was developed in C and it was tested in Xen Virtual Machine Monitor. The MD showed memory gains up to 70%.