12 documents found, page 1 of 2
Diagnosing applications' I/O behavior through system call observability
Esteves, Tania; Macedo, Ricardo; Oliveira, Rui Carlos Mendes de; Paulo, JoaoWe present DIO, a generic tool for observing inefficient and erroneous I/O interactions between applications and in-kernel storage systems that lead to performance, dependability, and correctness issues. DIO facilitates the analysis and enables near real-time visualization of complex I/O patterns for data-intensive applications generating millions of storage requests. This is achieved by non-intrusively interce...
Toward a practical and timely diagnosis of application's I/O behavior
Esteves, Tania; Macedo, Ricardo; Oliveira, Rui Carlos Mendes de; Paulo, JoaoWe present DIO, a generic tool for observing inefficient and erroneous I/O interactions between applications and in-kernel storage backends that lead to performance, dependability, and correctness issues. DIO eases the analysis and enables near real-time visualization of complex I/O patterns for data-intensive applications generating millions of storage requests. This is achieved by non-intrusively intercepting...
Taming metadata-intensive HPC jobs through dynamic, application-agnostic QoS co...
Macedo, Ricardo; Miranda, Mariana; Tanimura, Yusuke; Haga, Jason; Ruhela, Amit; Harrell, Stephen Lien; Evans, Richard Todd; Pereira, José; Paulo, JoãoModern I/O applications that run on HPC infrastructures are increasingly becoming read and metadata intensive. However, having multiple applications submitting large amounts of metadata operations can easily saturate the shared parallel file system's metadata resources, leading to overall performance degradation and I/O unfairness. We present PADLL, an application and file system agnostic storage middleware tha...
PAIO: general, portable I/O optimizations with minor application modifications
Macedo, Ricardo; Tanimura, Y.; Haga, Jason; Chidambaram, Vijay; Pereira, José; Paulo, JoãoWe present PAIO, a framework that allows developers to implement portable I/O policies and optimizations for different applications with minor modifications to their original code base. The chief insight behind PAIO is that if we are able to intercept and differentiate requests as they flow through different layers of the I/O stack, we can enforce complex storage policies without significantly changing the laye...
BDUS: implementing block devices in user space
Faria, Alberto; Macedo, Ricardo; Pereira, José; Paulo, JoãoModern general-purpose operating systems implement major parts of their storage stacks in the kernel. Although this bolsters performance, it also complicates development and stifles innovation for today's increasingly complex storage systems. In contrast, implementing system services at the user level eases development and maintenance, and leads to improved portability, reliability, fault tolerance, and securit...
A survey and classification of software-defined storage systems
Macedo, Ricardo; Paulo, Joao; Pereira, José; Bessani, AlyssonThe exponential growth of digital information is imposing increasing scale and efficiency demands on modern storage infrastructures. As infrastructure complexity increases, so does the difficulty in ensuring quality of service, maintainability, and resource fairness, raising unprecedented performance, scalability, and programmability challenges. Software-Defined Storage (SDS) addresses these challenges by clean...
TRUSTFS: an SGX-enabled stackable file system framework
Esteves, Tânia; Macedo, Ricardo; Faria, Alberto; Portela, Bernardo; Paulo, João; Pereira, José; Harnik, DannyData confidentiality in cloud services is commonly ensured by encrypting information before uploading it. However, this approach limits the use of content-aware functionalities, such as deduplication and compression. Although this issue has been addressed individually for some of these functionalities, no unified framework for building secure storage systems exists that can leverage such operations over encrypt...
A case for dynamically programmable storage background tasks
Macedo, Ricardo; Faria, Alberto; Paulo, João; Pereira, JoséModern storage infrastructures feature long and complicated I/O paths composed of several layers, each employing their own optimizations to serve varied applications with fluctuating requirements. However, as these layers do not have global infrastructure visibility, they are unable to optimally tune their behavior to achieve maximum performance. Background storage tasks, in particular, can rapidly overload sha...
Anaesthesia in Dental Medicine with Local Infiltrative Anaesthetic Technique Ve...
Ferreira, Manuel; Carrilho, Eunice; Paulo, Siri; Carrilho, Teresa; Figueiredo, José Pedro; Macedo, RicardoThis study aimed to compare the analgesic efficacy and the influence of local infiltrative anesthesia techniques, with diploe anesthesia, on the cardiac rhythmMaterial and Methods: We selected 32 healthy volunteers who were given both anaesthetic techniques on tooth 1.4 (0.45 mL of lidocaine with adrenaline, 1:80 000). In the first phase, the volunteers underwent periapical infiltrative anaesthesia. In the seco...
Anaesthesia in Dental Medicine with Local Infiltrative Anaesthetic Technique Ve...
Marques-Ferreira, Manuel; Carrilho, Eunice; Paulo, Siri; Carrilho, Teresa; Figueiredo, José Pedro; Macedo, RicardoIntroduction: This study aimed to compare the analgesic efficacy and the influence of local infiltrative anesthesia techniques, with diploe anesthesia, on the cardiac rhythmMaterial and Methods: We selected 32 healthy volunteers who were given both anaesthetic techniques on tooth 1.4 (0.45 mL of lidocaine with adrenaline, 1:80 000). In the first phase, the volunteers underwent periapical infiltrative anaesthesi...