"But is there still 2B columns limit on the Cassandra code?" --> I remember some one the committer saying that this 2B columns limitation comes from the Thrift era where you're limited to max 2B columns to be returned to the client for each request. It also applies to the max size of each "page" of data
Since the introduction of the binary protocol and the paging feature, this limitation does not make sense anymore. By the way, if your partition is too wide, you'll face other operational issues way before reaching the 2B columns limit: - compaction taking looooong time --> heap pressure --> long GC pauses --> nodes flapping - repair & over-streaming, repair session failure in the middle that forces you to re-send the whole big partition --> the receiving node has a bunch of duplicate data --> pressure on compaction - bootstrapping of new nodes --> failure to stream a partition in the middle will force to re-send the whole partition from the beginning again --> the receiving node has a bunch of duplicate data --> pressure on compaction On Sat, Oct 15, 2016 at 9:15 AM, Kant Kodali <k...@peernova.com> wrote: > compacting 10 sstables each of them have a 15GB partition in what > duration? > > On Fri, Oct 14, 2016 at 11:45 PM, Matope Ono <matope....@gmail.com> wrote: > >> Please forget the part in my sentence. >> For more correctly, maybe I should have said like "He could compact 10 >> sstables each of them have a 15GB partition". >> What I wanted to say is we can store much more rows(and columns) in a >> partition than before 3.6. >> >> 2016-10-15 15:34 GMT+09:00 Kant Kodali <k...@peernova.com>: >> >>> "Robert said he could treat safely 10 15GB partitions at his >>> presentation" This sounds like there is there is a row limit too not >>> only columns?? >>> >>> If I am reading this correctly 10 15GB partitions means 10 partitions >>> (like 10 row keys, thats too small) with each partition of size 15GB. >>> (thats like 15 million columns where each column can have a data of size >>> 1KB). >>> >>> On Fri, Oct 14, 2016 at 11:30 PM, Kant Kodali <k...@peernova.com> wrote: >>> >>>> "Robert said he could treat safely 10 15GB partitions at his >>>> presentation" This sounds like there is there is a row limit too not >>>> only columns?? >>>> >>>> If I am reading this correctly 10 15GB partitions means 10 partitions >>>> (like 10 row keys, thats too small) with each partition of size 15GB. >>>> (thats like 10 million columns where each column can have a data of size >>>> 1KB). >>>> >>>> >>>> >>>> >>>> >>>> On Fri, Oct 14, 2016 at 9:54 PM, Matope Ono <matope....@gmail.com> >>>> wrote: >>>> >>>>> Thanks to CASSANDRA-11206, I think we can have much larger partition >>>>> than before 3.6. >>>>> (Robert said he could treat safely 10 15GB partitions at his >>>>> presentation. https://www.youtube.com/watch?v=N3mGxgnUiRY) >>>>> >>>>> But is there still 2B columns limit on the Cassandra code? >>>>> If so, out of curiosity, I'd like to know where the bottleneck is. >>>>> Could anyone let me know about it? >>>>> >>>>> Thanks Yasuharu. >>>>> >>>>> >>>>> 2016-10-13 1:11 GMT+09:00 Edward Capriolo <edlinuxg...@gmail.com>: >>>>> >>>>>> The "2 billion column limit" press clipping "puffery". This statement >>>>>> seemingly became popular because highly traffic traffic-ed story, in >>>>>> which >>>>>> a tech reporter embellished on a statement to make a splashy article. >>>>>> >>>>>> The effect is something like this: >>>>>> http://www.healthnewsreview.org/2012/08/iced-tea-kidney-ston >>>>>> es-and-the-study-that-never-existed/ >>>>>> >>>>>> Iced tea does not cause kidney stones! Cassandra does not store rows >>>>>> with 2 billion columns! It is just not true. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> On Wed, Oct 12, 2016 at 4:57 AM, Kant Kodali <k...@peernova.com> >>>>>> wrote: >>>>>> >>>>>>> Well 1) I have not sent it to postgresql mailing lists 2) I thought >>>>>>> this is an open ended question as it can involve ideas from everywhere >>>>>>> including the Cassandra java driver mailing lists so sorry If that >>>>>>> bothered >>>>>>> you for some reason. >>>>>>> >>>>>>> On Wed, Oct 12, 2016 at 1:41 AM, Dorian Hoxha < >>>>>>> dorian.ho...@gmail.com> wrote: >>>>>>> >>>>>>>> Also, I'm not sure, but I don't think it's "cool" to write to >>>>>>>> multiple lists in the same message. (based on postgresql mailing lists >>>>>>>> rules). >>>>>>>> Example I'm not subscribed to those, and now the messages are >>>>>>>> separated. >>>>>>>> >>>>>>>> On Wed, Oct 12, 2016 at 10:37 AM, Dorian Hoxha < >>>>>>>> dorian.ho...@gmail.com> wrote: >>>>>>>> >>>>>>>>> There are some issues working on larger partitions. >>>>>>>>> Hbase doesn't do what you say! You have also to be carefull on >>>>>>>>> hbase not to create large rows! But since they are globally-sorted, >>>>>>>>> you can >>>>>>>>> easily sort between them and create small rows. >>>>>>>>> >>>>>>>>> In my opinion, cassandra people are wrong, in that they say >>>>>>>>> "globally sorted is the devil!" while all fb/google/etc actually use >>>>>>>>> globally-sorted most of the time! You have to be careful though (just >>>>>>>>> like >>>>>>>>> with random partition) >>>>>>>>> >>>>>>>>> Can you tell what rowkey1, page1, col(x) actually are ? Maybe >>>>>>>>> there is a way. >>>>>>>>> The most "recent", means there's a timestamp in there ? >>>>>>>>> >>>>>>>>> On Wed, Oct 12, 2016 at 9:58 AM, Kant Kodali <k...@peernova.com> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> Hi All, >>>>>>>>>> >>>>>>>>>> I understand Cassandra can have a maximum of 2B rows per >>>>>>>>>> partition but in practice some people seem to suggest the magic >>>>>>>>>> number is >>>>>>>>>> 100K. why not create another partition/rowkey automatically >>>>>>>>>> (whenever we >>>>>>>>>> reach a safe limit that we consider would be efficient) with auto >>>>>>>>>> increment bigint as a suffix appended to the new rowkey? so that the >>>>>>>>>> driver can return the new rowkey indicating that there is a new >>>>>>>>>> partition >>>>>>>>>> and so on...Now I understand this would involve allowing partial row >>>>>>>>>> key >>>>>>>>>> searches which currently Cassandra wouldn't do (but I believe HBASE >>>>>>>>>> does) >>>>>>>>>> and thinking about token ranges and potentially many other things.. >>>>>>>>>> >>>>>>>>>> My current problem is this >>>>>>>>>> >>>>>>>>>> I have a row key followed by bunch of columns (this is not time >>>>>>>>>> series data) >>>>>>>>>> and these columns can grow to any number so since I have 100K >>>>>>>>>> limit (or whatever the number is. say some limit) I want to break the >>>>>>>>>> partition into level/pages >>>>>>>>>> >>>>>>>>>> rowkey1, page1->col1, col2, col3...... >>>>>>>>>> rowkey1, page2->col1, col2, col3...... >>>>>>>>>> >>>>>>>>>> now say my Cassandra db is populated with data and say my >>>>>>>>>> application just got booted up and I want to most recent value of a >>>>>>>>>> certain >>>>>>>>>> partition but I don't know which page it belongs to since my >>>>>>>>>> application >>>>>>>>>> just got booted up? how do I solve this in the most efficient that is >>>>>>>>>> possible in Cassandra today? I understand I can create MV, other >>>>>>>>>> tables >>>>>>>>>> that can hold some auxiliary data such as number of pages per >>>>>>>>>> partition and >>>>>>>>>> so on..but that involves the maintenance cost of that other table >>>>>>>>>> which I >>>>>>>>>> cannot afford really because I have MV's, secondary indexes for >>>>>>>>>> other good >>>>>>>>>> reasons. so it would be great if someone can explain the best way >>>>>>>>>> possible >>>>>>>>>> as of today with Cassandra? By best way I mean is it possible with >>>>>>>>>> one >>>>>>>>>> request? If Yes, then how? If not, then what is the next best way to >>>>>>>>>> solve >>>>>>>>>> this? >>>>>>>>>> >>>>>>>>>> Thanks, >>>>>>>>>> kant >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
