Apparently the MemTable..writeSortedContents has the same problem: I can see how it iterates over the stored keys in byte order, so my classes have something wrong. For the curious, these are my classes until now:
https://gist.github.com/anonymous/5261611 Carlos Pérez Miguel 2013/3/28 aaron morton <aa...@thelastpickle.com> > That is the order I would expect to find if I read the CF, but if I do, I > obtain (with any client or library I've tried): > > > What happens if you export sstables with sstable2json ? > > Put some logging in Memtable.FlushRunnable.writeSortedContents to see the > order the rows are written > > Cheers > > ----------------- > Aaron Morton > Freelance Cassandra Consultant > New Zealand > > @aaronmorton > http://www.thelastpickle.com > > On 28/03/2013, at 5:05 AM, Carlos Pérez Miguel <cperez...@gmail.com> > wrote: > > Thanks, Lanny. That is what I am doing. > > Actually I'm having another problem. My UUIDOrderedPartitioner doesn't > order by time. Instead, it orders by byte order and I cannot find why. > Which are the functions that control ordering between tokens? I have > implemented time ordering in the "compareTo" function of my UUID token > class, but it seems that Cassandra is ignoring it. For example: > > Let's suppouse that I have a Users CF where each row represents a user in > a cluster of 1 node. Rows are ordered by TimeUUID. I create some users in > the next order: > > user a created with user_id: eac850fa-96f4-11e2-9f22-72ad6af0e500 > user b created with user_id: f17f9ae8-96f4-11e2-98aa-421151417092 > user c created with user_id: f82fccfa-96f4-11e2-8d99-26f8461d074c > user d created with user_id: fee21cec-96f4-11e2-945b-f9a2a2e32308 > user e created with user_id: 058ec180-96f5-11e2-8c88-4aaf94e4f04e > user f created with user_id: 0c5032ba-96f5-11e2-95a5-60a128c0b3f4 > user g created with user_id: 13036b86-96f5-11e2-80dd-566654c686cb > user h created with user_id: 19b245f6-96f5-11e2-9c8f-b315f455e5e0 > > That is the order I would expect to find if I read the CF, but if I do, I > obtain (with any client or library I've tried): > > user_id: 058ec180-96f5-11e2-8c88-4aaf94e4f04e name:"e" > user_id: 0c5032ba-96f5-11e2-95a5-60a128c0b3f4 name:"f" > user_id: 13036b86-96f5-11e2-80dd-566654c686cb name:"g" > user_id: 19b245f6-96f5-11e2-9c8f-b315f455e5e0 name:"h" > user_id: eac850fa-96f4-11e2-9f22-72ad6af0e500 name:"a" > user_id: f17f9ae8-96f4-11e2-98aa-421151417092 name:"b" > user_id: f82fccfa-96f4-11e2-8d99-26f8461d074c name:"c" > user_id: fee21cec-96f4-11e2-945b-f9a2a2e32308 name:"d" > > Any idea what's happening? > > > Carlos Pérez Miguel > > > 2013/3/27 Lanny Ripple <la...@spotright.com> > >> Ah. TimeUUID. Not as useful for you then but still something for the >> toolbox. >> >> On Mar 27, 2013, at 8:42 AM, Lanny Ripple <la...@spotright.com> wrote: >> >> > A type 4 UUID can be created from two Longs. You could MD5 your >> strings giving you 128 hashed bits and then make UUIDs out of that. Using >> Scala: >> > >> > import java.nio.ByteBuffer >> > import java.security.MessageDigest >> > import java.util.UUID >> > >> > val key = "Hello, World!" >> > >> > val md = MessageDigest.getInstance("MD5") >> > val dig = md.digest(key.getBytes("UTF-8")) >> > val bb = ByteBuffer.wrap(dig) >> > >> > val msb = bb.getLong >> > val lsb = bb.getLong >> > >> > val uuid = new UUID(msb, lsb) >> > >> > >> > On Mar 26, 2013, at 3:22 PM, aaron morton <aa...@thelastpickle.com> >> wrote: >> > >> >>> Any idea? >> >> Not off the top of my head. >> >> >> >> Cheers >> >> >> >> ----------------- >> >> Aaron Morton >> >> Freelance Cassandra Consultant >> >> New Zealand >> >> >> >> @aaronmorton >> >> http://www.thelastpickle.com >> >> >> >> On 26/03/2013, at 2:13 AM, Carlos Pérez Miguel <cperez...@gmail.com> >> wrote: >> >> >> >>> Yes it does. Thank you Aaron. >> >>> >> >>> Now I realized that the system keyspace uses string as keys, like >> "Ring" or "ClusterName", and I don't know how to convert these type of keys >> into UUID. Any idea? >> >>> >> >>> >> >>> Carlos Pérez Miguel >> >>> >> >>> >> >>> 2013/3/25 aaron morton <aa...@thelastpickle.com> >> >>> The best thing to do is start with a look at ByteOrderedPartitoner >> and AbstractByteOrderedPartitioner. >> >>> >> >>> You'll want to create a new TimeUUIDToken extends Token<UUID> and a >> new UUIDPartitioner that extends AbstractPartitioner<> >> >>> >> >>> Usual disclaimer that ordered partitioners cause problems with load >> balancing. >> >>> >> >>> Hope that helps. >> >>> >> >>> ----------------- >> >>> Aaron Morton >> >>> Freelance Cassandra Consultant >> >>> New Zealand >> >>> >> >>> @aaronmorton >> >>> http://www.thelastpickle.com >> >>> >> >>> On 25/03/2013, at 1:12 AM, Carlos Pérez Miguel <cperez...@gmail.com> >> wrote: >> >>> >> >>>> Hi, >> >>>> >> >>>> I store in my system rows where the key is a UUID version1, >> TimeUUID. I would like to maintain rows ordered by time. I know that in >> this case, it is recomended to use an external CF where column names are >> UUID ordered by time. But in my use case this is not possible, so I would >> like to use a custom Partitioner in order to do this. If I use >> ByteOrderedPartitioner rows are not correctly ordered because of the way a >> UUID stores the timestamp. What is needed in order to implement my own >> Partitioner? >> >>>> >> >>>> Thank you. >> >>>> >> >>>> Carlos Pérez Miguel >> >>> >> >>> >> >> >> > >> >> > >
