Robert, You grouping_with_date_rollup.py example was extremely helpful. Thanks a lot again! :)
On Oct 14, 8:47 pm, Robert Kluin <robert.kl...@gmail.com> wrote: > Hey Carles, > Glad it seems helpful. I am hoping to get time today to push out > some revisions and sample code. > > Robert > > On Thu, Oct 14, 2010 at 05:50, Carles Gonzalez <carle...@gmail.com> wrote: > > Robert, I took a brief inspection at your code and seems very cool. Exactly > > what i was lloking for for my report generation and such. > > I'm looking forward for more examples, but it seems a very valuable addition > > for our toolbox. > > Thanks a lot! > > > On Wed, Oct 13, 2010 at 9:20 PM, Carles Gonzalez <carle...@gmail.com> wrote: > > >> Neat! I'm going to see this code, hopefully I'll understand something :) > >> On Wednesday, October 13, 2010, Robert Kluin <robert.kl...@gmail.com> > >> wrote: > >> > Hey Dmitry, > >> > In case it might help, I pushed some code to bitbucket. At the > >> > moment I would (personally) say the code is not too pretty, but it > >> > works well. :) > >> > http://bitbucket.org/thebobert/slagg > > >> > Sorry it does not really have good documentation at the moment, but > >> > I think the basic example I threw together will give you a good idea > >> > of how to use it. I need to do another cleanup pass over the API to > >> > make a few more refinements. > > >> > I pulled this code out of one of my apps, and tried to quickly > >> > refactor it to be a bit more generic. We are currently using > >> > basically the same code in three apps to do some really complex > >> > calculations. As soon as I get time I will get an example up showing > >> > how to use it for neat stuff, like overall, yearly, monthly, and daily > >> > aggregates across multiple values (like total dollars and quantity). > >> > The cool thing is that you can do all of those aggregations across > >> > various groupings, like customer, company, contact, and sales-person, > >> > at once. I'll get that code pushed out in the next few days. > > >> > Would love to get some feedback on it. > > >> > Robert > > >> > On Tue, Oct 12, 2010 at 17:26, Dmitry <dmitry.lukas...@gmail.com> wrote: > >> >> Ben, thanks for your code! I'm trying to understand all this stuff > >> >> too... > >> >> Robert, any success with your "library"? May be you've already done > >> >> all stuff we are trying to implement... > > >> >> p.s. where is Brett S.:) would like to hear his comments on this > > >> >> On Sep 21, 1:49 pm, Ben <pondneverfree...@yahoo.com> wrote: > >> >>> Thanks for your insights. I would love feedback on this implementation > >> >>> (Brett S. suggested we send in our code for > >> >>> this)http://pastebin.com/3pUhFdk8 > > >> >>> This implementation is for just one materialized view row at a time > >> >>> (e.g. a simple counter, no presence markers). Hopefully putting an ETA > >> >>> on the transactional task will relieve the write pressure, since > >> >>> usually it should be an old update with an out-of-date sequence number > >> >>> and be discarded (the update having already been completed in batch by > >> >>> the fork-join-queue). > > >> >>> I'd love to generalize this to do more than one materialized view row > >> >>> but thought I'd get feedback first. > > >> >>> Thanks, > >> >>> Ben > > >> >>> On Sep 17, 7:30 am, Robert Kluin <robert.kl...@gmail.com> wrote: > > >> >>> > Responses inline. > > >> >>> > On Thu, Sep 16, 2010 at 17:32, Ben <pondneverfree...@yahoo.com> > >> >>> > wrote: > >> >>> > > I have a question about Brett Slatkin's talk at I/O 2010 on data > >> >>> > > pipelines. The question is about slide #67 of his pdf, > >> >>> > > corresponding > >> >>> > > to minute 51:30 of his talk > > >> >>> > > >http://code.google.com/events/io/2010/sessions/high-throughput-data-p... > > >> >>> > > I am wondering what is supposed to happen in the transactional > >> >>> > > task > >> >>> > > (bullet point 2c). Would these updates to the materialized view > >> >>> > > cause > >> >>> > > you to write too frequently to the entity group containing the > >> >>> > > materialized view? > > >> >>> > I think there are really two different approaches you can use to > >> >>> > insert your work models. > >> >>> > 1) The work models get added to the original entity's group. So, > >> >>> > inside of the original transaction you do not write to the entity > >> >>> > group containing the materialized view -- so no contention on it. > >> >>> > Commit the transaction and proceed to step 3. > >> >>> > 2) You kick off a transactional task to insert the work model, or > >> >>> > fan-out more tasks to create work models :). Then you proceed to > >> >>> > step 3. > > >> >>> > You can use method 1 if you have only a few aggregates. If you have > >> >>> > more aggregates use the second method. I have a "library" I am > >> >>> > almost > >> >>> > ready to open source that makes method 2 really easy, so you can > >> >>> > have > >> >>> > lots of aggregates. I'll post to this group when I release it. > > >> >>> > > And a related question, what happens if there is a failure just > >> >>> > > after > >> >>> > > the transaction in bullet #2, but right before the named task gets > >> >>> > > inserted in bullet #3. In my current implementation I just left > >> >>> > > out > >> >>> > > the transactional task (bullet point 2c) but I think that causes > >> >>> > > me to > >> >>> > > lose the eventual consistency. > > >> >>> > Failure between steps 2 and 3 just means _that_ particular update > >> >>> > will > >> >>> > not try to kick-off, ie insert, the fan-in (aggregation) task. But > >> >>> > it > >> >>> > might have already been inserted by the previous update, or the next > >> >>> > update. However, if nothing else kicks of the fan-in task you will > >> >>> > need some periodic "cleanup" method to catch the update and kick of > >> >>> > the fan-in task. Depending on exactly how you implemented step 2 > >> >>> > you > >> >>> > may not need a transactional task. > > >> >>> > Robert > > >> >>> > > Thanks! > > > -- > > You received this message because you are subscribed to the Google Groups > > "Google App Engine" group. > > To post to this group, send email to google-appeng...@googlegroups.com. > > To unsubscribe from this group, send email to > > google-appengine+unsubscr...@googlegroups.com. > > For more options, visit this group at > >http://groups.google.com/group/google-appengine?hl=en. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appeng...@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
