Seer: a lightweight online failure prediction approach

Online failure prediction aims to predict the manifestation of failures at runtime before the failures actually occur. Existing online failure prediction approaches typically operate on data which is either directly reported by the system under test or directly observable from outside system executions. These approaches generally refrain themselves from collecting internal execution data that can further improve the prediction quality. One reason behind this general trend is due to the runtime overhead cost incurred by the measurement instruments that are required to collect the data. In this work we conjecture that large cost reductions in collecting internal execution data for online failure prediction can derive from reducing the cost of the measurement instruments, while still supporting acceptable levels of prediction quality. To evaluate this conjecture, we present a lightweight online failure prediction approach, called Seer. Seer uses fast hardware performance counters to perform most of the data collection work. The data is augmented with further data collected by a minimal amount of software instrumentation that is added to the systems software. We refer to the data collected in this manner as hybrid spectra. We applied the proposed approach to three widely used open source subject applications and evaluated it by comparing and contrasting three types of hybrid spectra and two types of traditional software spectra. At the lowest level of runtime overheads attained in the experiments, the hybrid spectra predicted the failures about half way through the executions with an F-measure of 0.77 and a runtime overhead of 1.98%, on average. Comparing hybrid spectra to software spectra, we observed that, for comparable runtime overhead levels, the hybrid spectra provided significantly better prediction accuracies and earlier warnings for failures than the software spectra. Alternatively, for comparable accuracy levels, the hybrid spectra incurred significantly less runtime overheads and provided earlier warnings

Factors affecting the outcome of surgically treated non-iatrogenic traumatic cervical esophageal perforation: 28 years experience at a single center

<p>Abstract</p> <p>Background</p> <p>We reviewed our experience with non-iatrogenic traumatic cervical esophageal perforations, paying particular attention to factors affecting the outcome of such cases.</p> <p>Methods</p> <p>In total, 30 patients treated surgically between 1980 and 2008 for non-iatrogenic traumatic cervical esophageal perforation in our clinic were reviewed.</p> <p>Results</p> <p>There were 25 male and 5 female patients with a median age of 27.5 years. The type of injury was external trauma in 21 (70%) patients and endoluminal injury in the remaining 9 (30%) patients. The mechanism of injury was gunshot in 16 patients, stabbing in 4, falling in 1 (extraluminal injury), and foreign body in 9 (endoluminal injuries). The overall mortality rate was 16.6% (5/30). The mortality rate for extraluminal injuries was 19%, and for endoluminal injuries was 11.1%. Mortality in patients treated within 24 h of sustaining injury was substantially less than in those for whom diagnosis and treatment were delayed (12.5 and 21.4%, respectively). The mortality rate was 33.3% (3/9) for patients with tracheal injuries and 9.5% (2/21) for those without tracheal injuries.</p> <p>Conclusions</p> <p>A treatment delay greater than 24 h, the presence of tracheal injury, or extraluminal perforation significantly affected the outcome of surgically treated non iatrogenic traumatic cervical esophageal perforation.</p

The Role of Sublobar Resections in the Treatment of Small Cell Lung

WOS: 000446224000008Lobectomy is the standard treatment in the early stages of non-small cell lung cancer. Today, however, it is questioned whether lobectomy should be performed in all early diagnosed patients. Sublobar resection remains a treatment option in elderly patients with low cardiopulmonary reserve who cannot tolerate sublobar resection lobectomy. In small tumors measuring 2 cm in diameter, sublobar resections can provide local recurrence rates and long survival rates equivalent to lobectomy when performed with the appropriate techniques in eligible patients. The addition of brachytherapy can further improve the results

Congenital lobar emphysema

Background: Congenital lobar emphysema (CLE) is a rare anomaly of lung development that usually presents in the neonatal period with respirator distress and pulmonary lobar hyperinflation. It is commonly confused with pneumothorax. The aim of the present paper was to review the authors' experience in order to emphasize the importance of differential diagnosis with pneumothorax. Methods: Children with CLE treatment at Department of Thoracic Surgery, Dicle University School of Medicine, Turkey, between January 1993 and June 2004, were reviewed. Results: Ten children consisting of six boys and four girls (age range, 6 h-12 months) had CLE. Major presenting symptoms were tachypnea(n = 100%) and respiratory distress in (n = 80%). On chest radiograph, emphysema was seen in all patients, and shift-herniation to the opposite lung, atelectasis were observed. Computed tomography was performed in all patients, which indicated emphysema in the affected lobes in all cases. Pulmonary perfusion scan was performed in two patients, showing loss of perfusion in the affected lobe. The most common affected lobe was the left upper lobe (50%). In the present series, three patients were mistakenly diagnosed as pneumothorax and intercostal drains were inserted in the emergency department. Eight patients underwent lobectomy, and postoperative course was uneventful. Two patients were followed conservatively. Emphysema was detected in all pathological specimens. One patient was lost to follow up. Mean follow-up duration of all patients was 26.8 +/- 29.24 months (range, 1-89 months). Conclusions: CLE is established on combined clinical, radiological and scintigraphic imaging. Surgical excision of the affected lobe is the appropriate treatment. Particularly, differential diagnosis should be made between CLE and pneumothorax

An Approach for Classifying Program Failures

Abstract—In this work, we leverage hardware performance counters-collected data to automatically group program failures that stem from closely related causes into clusters, which can in turn help developers prioritize failures as well as diagnose their causes. Hardware counters have been used for performance analysis of software systems in the past. By contrast, in this paper they are used as abstraction mechanisms for program executions. The results of our feasibility studies conducted on two widely-used applications suggest that hardware counters-collected data can be used to reliably classify failures. Keywords-failure classification; debugging aids; hardware performance counters. I

Treatment of pediatric parapneumonic empyemas with pulmonary cavitary lesions

Background: This study aims to evaluate the treatment approach and timing of surgical intervention in pediatric parapneumonic empyema cases with cavitary lesions. Methods: Between January 1990 and December 2006, 38 patients (21 boys, 17 girls; mean age 4.1+2 years; range 1 to 15 years) from the pediatric age group treated for parapneumonic empyema with cavitary lung lesions at the Dicle University Faculty of Medicine Department of Thoracic Surgery were retrospectively analyzed. The demographic characteristics, symptom duration, radiological examinations, treatment methods, and time to recovery of cavitary lesions during the hospitalization and follow-up were evaluated. Results: A total of 13 patients (34%) were given medical treatment, while 25 (66%) underwent surgical treatment. The medical treatment group had a statistically significantly shorter inpatient duration than the surgical treatment group (p=0.010). Analysis of the postoperative inpatient duration revealed that the surgically treated patients stayed statistically significantly shorter in the hospital than the medical treatment group (p<0.001). A bronchopleural fistula (BPF) was found in eight (21%) patients and all were in the surgical treatment group. The mean time to recovery of cavitary lesions during follow-up was 48.7 +/- 8 days (range, 22-106 days). Conclusion: Treatment of parapneumonic pediatric empyema cases with cavitary lesions should include controlling the pleural process with standard empyema treatment, considering pneumonia treatment as an integral part of the disorder, performing surgical treatment if a bronchopleural fistula is present or otherwise waiting patiently for the cavitary lesions to regress and postponing open surgical treatment until the recovery period is completed