Hello Hyunsik, sorry for that stupid question at page 21. The acronym GC is determined Garbage Collection in this context.
Best regards, Chris Am 29.08.2014 um 14:02 schrieb Christian Schwabe <[email protected]>: > > Hello Hyunsik > > I've found this presentation > (http://www.slideshare.net/gruter/hadoop-summit-2014-query-optimization-and-jitbased-vectorized-execution-in-apache-tajo) > which explained detailed the processing for Tajo a while ago, but wanted to > first deal with the basics of Tajo. I think to have understood this now and > would now like to ask more detailed questions. > However, still unanswered questions stay op to this presentation I would like > to clarify here. > > Page 6: Can you explain in more detail what exact tasks the modules in the > Tajo Master have? > Page 7: What is a "DAG"-Controller? What does the shortcut "DAG" means? Can > you explain the figure in more details what exactly happens in every step? > Page 12: What is a "BMT"-Controller? What does the shortcut "BMT" means? > Page 21: What is a "GC"-Controller? What does the shortcut "GC" means? > > I thank you and your team for your versatile help and that they could answer > all questions I had in the past. > > > P.S.: While I am writing currently on my thesis, but at the same I would like > to gave something back to this support I have also receivedfrom this > community. Is it possible to accept smaller tasks, such as grooming the > Documentation or other things are accessible to me? > > > Warm regards, > Chris > > > > Am 27.08.2014 11:03:56, schrieb Christian Schwabe: > Hello Hyunsik, > > Thank you very for your detailed descriptions of the creation of Tajo. > Tajo became to an Apache Top-Level Project in March 2014. What exactly mean > this status? What added value does this mean for you? > The current progress of Tajo is very promising. What exactly did you have > done for the near future? > > On the roadmap (http://wiki.apache.org/tajo/Roadmap) all entries are > outdated. This is quite a problem for the rapid progress of Tajo. The > documentation and transparency should not lose sight of ;) > > Warm regards, > Chris > > > Am 26.08.2014 um 04:42 schrieb Hyunsik Choi <[email protected]>: > > Hi, > > I'm sorry for late. My name is Hyunsik Choi who is one of the > founders of Tajo and now is the PMC chair of Tajo project. > > I'm going to explain the origin of Tajo. It was a research project in > Database Lab., Korea University. It started in May, 2010. At the first > time, we started it as an alternative to Hive. We designed Tajo to > take advantages of both shared-nothing parallel database and > specialized distributed data processing systems, like MapReduce, > Dryad, and Dremel. > > Jihoon Son and I mainly had worked on Tajo prototype. Later, Tajo > became the subject of my Ph.D. dissertation. At that time, I were also > working on some paper work, Parallel data processing with MapReduce: a > survey, ACM SIGMOD Record 2011 > (http://dl.acm.org/citation.cfm?id=2094118). I were investigating lots > of distributed processing systems and learned many things from them. > So, I made an effort to reflect great design considerations of other > distributed processing systems to the design of Tajo. > > At the first time, the design goals were scalability, high throughput, > advanced query optimization, and fault tolerance. So far, we still > have pursued them. > > Since 2013, Gruter, a big data company, have supported Tajo project, > and it is employing some full time contributors (i.e., 3 PMC and one > committer), including me. > > As you mentioned, Tajo documentation does not follow the current > status of Tajo project because Tajo is very rapidly evolving and we do > not have contributors enough to update continuously documentations. > We've just periodically updated the documentation for each release. We > are recruiting contributors for code and documentation. > > Q. How did you come to the name of Tajo? > > When we decided to propose Tajo as an ASF incubation project, the > members in the DB Lab. voted for proper name suited for Hadoop eco > systems. We wanted to use some animal name like other systems in > Hadoop eco system. Finally, we chose Tajo, meaning Ostrich in Korean. > > If you have more questions about Tajo, feel free to ask anything. > > Best regards, > Hyunsik > > On Sun, Aug 24, 2014 at 2:29 AM, Hyunsik Choi <[email protected]: > Hi Chris, > > Nice question! Tajo also has interesting history. I'll give the > details of history tomorrow because here is too late :) > > Best regards, > Hyunsik > > On Sat, Aug 23, 2014 at 1:28 AM, Christian Schwabe > <[email protected]> wrote: > Hello everyone, > > For about three months now I am dealing with Tajo. Here, I received an > insight into the documentation especially now know how to start with Tajo, > which error it can be committed, have made me an overview of the Jira > tickets and read existing documentation. > > I'm fascinated by how fast this community has grown and how far you're come > previously and caused the potential Tajo. > What I would like to employ me now closer is the historical and technical > view of Tajo. > That means I ask myself questions like: How did you come to the name of > Tajo? When was indeed set the first milestone? Everywhere I read the year > 2013. But is this actually the first time at which the first time was > thought about Tajo? Who is the initiator of this project? > Above all technical processes would be interested in me and certainly other > very much. Apart from a few presentations on tajo.apache.org >> News there > is little documentation, or I have not found it yet. > In addition to the Jira tickets and documentation > (https://cwiki.apache.org/confluence/display/TAJO/Apache+TAJO+Home, > http://tajo.apache.org/docs/0.8.0/index.html ) I have the impression that > her somewhat neglected transparency in addition to the rapid technological > developments. This is only my own personal opinion and does not criticize > any individual. > I appreciate your work very much and can understand as Computer Science with > Business what it means for a development work. > > Can you give me more information on the points mentioned above? > > P.S.: I hope I was not misunderstood. I want to look more behind the scenes > of Tajo and learn to understand the technical background and the birth and > historical development of Tajo. > > Best regards, > Chris
