The rise of micro services as architectural pattern creates a bunch of interesting opportunities for software architectures of modelling editors and additional services. Main advantages are the scalability in collaborative distributed scenarios and enhanced possibilities regarding service development and operation. Throughout this article, we will illustrate how modelling editors and additional services can be build based on micro services. Our tooling will focus on business process modelling. We will also strive to highlight how architectures of this kind can enact collaborative modelling techniques, increase reuse of utilized service components and improve their integration into lightweight user interfaces, for example in mobile devices.
Distributed systems are usually large and complex systems composed of various components. Systemcomponents are subject to various errors. These failures often require error recovery to be conducted at architectural-level. However, due to complexity of distributed systems, specifying fault tolerance mechanisms at architectural level is complex and error prone. In this paper, we propose a formal approach to specifying components and architectures of fault tolerant distributed and reactive systems. Our approach is based on refinement in the action system formalism – a framework for formal model-driven development of distributed systems. We demonstrate how to specify and refine fault tolerant components and complex distributed systems composed of them. The proposed approach provides designers with a systematic method for developing distributed fault tolerant systems.
Author: Elena Troubitsyna ; Dept. of IT, Abo Akademi Univ., Turku, Finland
Distributed systems are notoriously difficult to implement and debug. One important tool for understanding the behavior of distributed systems is tracing. Unfortunately, effective tracing for moderndistributed systems faces several challenges. First, many interesting behaviors in distributed systemsonly occur rarely, or at full production scale. Hence we need tracing mechanisms which impose minimal overhead, in order to allow always-on tracing of production instances. Second, for high-speed systems, messages can be delivered in significantly less time than the error of traditional time synchronization techniques such as network time protocol (NTP), necessitating time adjustment techniques with much higher precision. Third, distributed systems today may generate millions of events per second systemwide, resulting in traces consisting of billions of events. Such large traces can overwhelm existing trace analysis tools. These challenges make effective tracing difficult. We present techniques that address these three challenges. Our contributions include (1) a low-overhead tracing mechanism, which allows tracing of large systems without impacting their behavior or performance (0.14 Â¿s/event), (2) a post hoc technique for producing highly accurate time synchronization across hosts (within 10/ts, compared to between 100 Â¿s to 2 ms for NTP), and (3) incremental data processing techniques which facilitate analyzing traces containing billions of trace points on desktop systems. We have successfully applied these techniques to two distributed systems, a cooperative caching systemand a distributed storage system, and from our experience, we believe our techniques are applicable to other distributed systems.
Background: The accurate prediction of where faults are likely to occur in code can help direct test effort, reduce costs, and improve the quality of software. Objective: We investigate how the context of models, the independent variables used, and the modeling techniques applied influence the performance of fault prediction models. Method: We used a systematic literature review to identify 208 fault prediction studies published from January 2000 to December 2010. We synthesize the quantitative and qualitative results of 36 studies which report sufficient contextual and methodological information according to the criteria we develop and apply. Results: The models that perform well tend to be based on simple modeling techniques such as Naive Bayes or Logistic Regression. Combinations of independent variables have been used by models that perform well. Feature selection has been applied to these combinations when models are performing particularly well. Conclusion: The methodology used to build models seems to be influential to predictive performance. Although there are a set of fault prediction studies in which confidence is possible, more studies are needed that use a reliable methodology and which report their context, methodology, and performance comprehensively.
© 2012 IEEE
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Empirical software engineering research needs research guidelines to improve the research and reporting processes. We propose a preliminary set of research guidelines aimed at stimulating discussion among software researchers. They are based on a review of research guidelines developed for medical researchers and on our own experience in doing and reviewing software engineering research. The guidelines are intended to assist researchers, reviewers, and meta-analysts in designing, conducting, and evaluating empirical studies. Editorial boards of software engineering journals may wish to use our recommendations as a basis for developing guidelines for reviewers and for framing policies for dealing with the design, data collection, and analysis and reporting of empirical studies.
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Due to significant industrial demands toward software systems with increasing complexity and challenging quality requirements, software architecture design has become an important development activity and the research domain is rapidly evolving. In the last decades, software architecture optimization methods, which aim to automate the search for an optimal architecture design with respect to a (set of) quality attribute(s), have proliferated. However, the reported results are fragmented over different research communities, multiple system domains, and multiple quality attributes. To integrate the existing research results, we have performed a systematic literature review and analyzed the results of 188 research papers from the different research communities. Based on this survey, a taxonomy has been created which is used to classify the existing research. Furthermore, the systematic analysis of the research literature provided in this review aims to help the research community in consolidating the existing research efforts and deriving a research agenda for future developments.
10 NOV 2015 OP-ED
Is becoming an “authentic leader” just an excuse for practicing a rigid management style? Bill George, who pioneered the idea, says critics don’t understand what really constitutes an authentic leader.
“Authenticity has become the gold standard for leadership”
—Harvard Business Review, January 2015
In the last 10 years, authenticity has become the gold standard of leadership. This is a sea change from 2003 when I wrote Authentic Leadership. Back then, many people asked what it meant to be authentic.Authentic Leadership was intended as a clarion call to the new generation to learn from negative examples like Enron, WorldCom and Tyco. In it, I defined authentic leaders as genuine, moral and character-based leaders:”People of the highest integrity, committed to building enduring organizations … who have a deep sense of purpose and are true to their core values who have the courage to build their companies to meet the needs of all their stakeholders, and who recognize the importance of their service to society.”Authentic leaders demonstrate these five qualities:
- Understanding their purpose
- Practicing solid values
- Leading with heart
- Establishing connected relationships
- Demonstrating self-discipline
The following year the Gallup Institute and Professor Bruce Avolio, a well-known leadership scholar at the University of Nebraska-Lincoln, organized a definitive conference on authentic leadership in which the importance of leaders’ life stories became paramount.In spite of widespread acceptance of authentic leadership—or perhaps because of it—several authors have recently challenged the value of being authentic, claiming it is an excuse for being locked into a rigid view of one’s leadership, being rude and insensitive, refusing to change, or not adapting to one’s style to the situation. These arguments appear to demonstrate a fundamental misunderstanding of what constitutes an authentic leader. Recommendations that leaders should accept narcissism, embrace their inner jerk, or focus on themselves will not work in the long-run.In light of this public discussion, it’s important to rediscover authentic leadership as well as examine some of the recent mischaracterizations of it.
Authentic leadership is built on your character, not your style. My mentor Warren Bennis said, “Leadership is character. It is not just a superficial question of style. It has to do with who we are as human beings and the forces that shaped us.Style is the outward manifestation of one’s authentic leadership, not one’s inner self. To become authentic leaders, people must adopt flexible styles that fit the situation and capabilities of their teammates. At times, authentic leaders are coaches and mentors, inspiring others and empowering their teammates to lead through the most important tasks without a great deal of supervision. At other times, authentic leaders must make very difficult decisions, terminating people and going against the will of the majority, as required to meet the situational imperative. These difficult actions can be taken while still retaining their authenticity.
Authentic leaders are real and genuine. You cannot “fake it till you make it” by putting on a show as a leader or being a chameleon in your style. People sense very quickly who is authentic and who is not. Some leaders may pull it off for a while, but ultimately they will not gain the trust of their teammates, especially when dealing with difficult situations. The widespread adoption of LinkedIn, Google and increasingly networked communities means that every leader has the informal equivalent of a “Yelp” score that will come to light. If people see their leaders as trustworthy and willing to learn, followers will respond very positively to requests for help in getting through difficult times.
Authentic leaders are constantly growing. They do not have a rigid view of themselves and their leadership. Becoming authentic is a developmental state that enables leaders to progress through multiple roles, as they learn and grow from their experiences. Like superior performances in athletics or music, becoming an authentic leader requires years of practice in challenging situations.
Authentic leaders match their behavior to their context, an essential part of emotional intelligence (EQ). They do not burst out with whatever they may be thinking or feeling. Rather, they exhibit self-monitoring, understand how they are being perceived, and use emotional intelligence (EQ) to communicate effectively.
Authentic leaders are not perfect, nor do they try to be. They make mistakes, but they are willing to admit their errors and learn from them. They know how to ask others for help. Nor are authentic leaders always humble or modest. It takes a great deal of self-confidence to lead through very difficult situations.
Authentic leaders are sensitive to the needs of others. One author has postulated, and I paraphrase, “What if your real self is a jerk?” People are not born as jerks, nor does this behavior reflect their authentic selves. Rather, these individuals likely had very negative experiences early in their lives that cause them to have difficulty in managing their anger, in part because they feel like victims or feel inadequate.Situations like these indicate the importance of processing one’s crucibles: people need not feel like victims or stuff their experiences deep inside themselves. Rather, by understanding themselves and reframing their experiences, they can find the pearl inside that represents their authentic selves. That’s why exploring who they are and getting honest feedback from their colleagues are essential elements of becoming authentic leaders. That’s what Starbucks’ Howard Schultz did in coping with the severe challenges of his youth. It is also what made the difference for Steve Jobs when he returned to Apple nine years after his 1986 termination.For all these reasons, authentic leaders constitute the vast majority of people chosen today for the key roles in business and nonprofits. Their emergence as the predominant way of leading has resulted from all we have discovered about leadership in the past decade.
A Human-Centered Approach to Leadership Development
My 2007 book, True North, showed people how they could develop themselves as authentic leaders. Whereas Authentic Leadership was based on my personal experiences in leading, True North was built on field research drawn from in-person interviews with 125 leaders. With 3,000 pages of transcripts, it remains as the largest in-depth study of leaders ever conducted, based on first-person interviews.Having examined the literature containing more than 1,000 studies of leaders, most of which employed third-person approaches of observations and questionnaires, our research team concluded that learning directly from these leaders about what was important to them and how they had developed would give us much richer insights than prior studies. Indeed, this proved to be the case, as we discovered the paramount importance of leaders’ life stories and the crucibles they had faced. We also learned from them how people develop into authentic leaders.In our research, we embraced the richness of understanding leadership as a fully human endeavor.
This approach built upon the pioneering work of Abraham Maslow, Carl Rogers, Douglas McGregor, Daniel Goleman and Warren Bennis. True North assembled this developmental process in an original approach that enabled people to develop themselves as authentic leaders.In order to see how leadership has changed in the past decade, we initiated research in 2014 that focused on 47 new leaders who were more global and diverse than the original cohort. We also followed up on 90 leaders featured in True North to see how they have fared since their 2005-06 interviews. With only a couple of exceptions, we learned these leaders had remained true to their authentic selves, and had performed very well in myriad roles.
This research led to my new book, Discover Your True North, which profiles 101 leaders and describes how they developed. It also draws heavily upon classroom experiences in the Authentic Leadership Development courses at Harvard Business School, where 6,000 MBAs and executives have participated in this developmental process.Most significantly, we learned that authentic leaders are constantly growing and learning from their leadership experiences. By taking on new challenges, they become more effective as authentic leaders. When they find themselves in entirely new situations, authentic leaders draw upon their true selves, what they have learned in past life experiences, especially their crucibles, and they learn from their new colleagues.
This enables them to become more effective as leaders. This approach is similar to Stanford’s Carol Dweck’s “growth mindset.”If you want to be an authentic leader and have a meaningful life, you need to do the difficult inner work to develop yourself, have a strong moral compass based on your beliefs and values, and work on problems that matter to you. When you look back on your life it may not be perfect, but it will be authentically yours.Bill George is the author of Discover Your True North, a senior fellow at Harvard Business School, and former chair and CEO of Medtronic.