Re: Cassandra in memory key index
If you are interested I can help, I used the FST on a Hadoop project to implement a fast map side range join. create JIRA item with patch attached, i will test it.
Re: Cassandra in memory key index
The Cassandra integration is probably beyond the time I have available. If the locations in the code that need to be rewritten to use the FST are known, and a patch simply 'plugs-in' the FST, that would be much easier. Eg, I don't know how Cassandra stores the current key index for example... Basically I can write FST serializing, deserializing, and key lookup code fairly easy by basing it on Lucene's terms dict. On Fri, Jun 8, 2012 at 6:00 AM, Radim Kolar wrote: > > If you are interested I can help, I used the FST on a Hadoop project >> to implement a fast map side range join. >> > create JIRA item with patch attached, i will test it. >
Re: Cassandra in memory key index
Ok looks like the IndexSummary encapsulates everything, I can start with hacking that. On Fri, Jun 8, 2012 at 11:50 AM, Jason Rutherglen < jason.rutherg...@gmail.com> wrote: > The Cassandra integration is probably beyond the time I have available. > If the locations in the code that need to be rewritten to use the FST are > known, and a patch simply 'plugs-in' the FST, that would be much easier. > Eg, I don't know how Cassandra stores the current key index for example... > > Basically I can write FST serializing, deserializing, and key lookup code > fairly easy by basing it on Lucene's terms dict. > > > On Fri, Jun 8, 2012 at 6:00 AM, Radim Kolar wrote: > >> >> If you are interested I can help, I used the FST on a Hadoop project >>> to implement a fast map side range join. >>> >> create JIRA item with patch attached, i will test it. >> > >
Re: Cassandra in memory key index
I would vote, if possible, to compare it with y-fast trie [1] (it doesn't seem to be available java implementation unfortunately) by means of memory efficiency and lookup performance. As we use big integer tokens the main benefit from that trie could be O(log log M) predecessor lookup and compact in-memory size. [1] https://en.wikipedia.org/wiki/Y-fast_trie Best Regards -- Pavel Yaskevich On Friday 8 June 2012 at 22:19, Jason Rutherglen wrote: > Ok looks like the IndexSummary encapsulates everything, I can start with > hacking that. > > On Fri, Jun 8, 2012 at 11:50 AM, Jason Rutherglen < > jason.rutherg...@gmail.com (mailto:jason.rutherg...@gmail.com)> wrote: > > > The Cassandra integration is probably beyond the time I have available. > > If the locations in the code that need to be rewritten to use the FST are > > known, and a patch simply 'plugs-in' the FST, that would be much easier. > > Eg, I don't know how Cassandra stores the current key index for example... > > > > Basically I can write FST serializing, deserializing, and key lookup code > > fairly easy by basing it on Lucene's terms dict. > > > > > > On Fri, Jun 8, 2012 at 6:00 AM, Radim Kolar > (mailto:h...@filez.com)> wrote: > > > > > > > > If you are interested I can help, I used the FST on a Hadoop project > > > > to implement a fast map side range join. > > > > > > create JIRA item with patch attached, i will test it. > > > > > > > > > >
Re: Cassandra in memory key index
Yeah that's fine, however if there isn't a Java implementation that's a lot of extra work. The FST approach should be a clear quick and easy win. The current system of in heap keys and a binary search is what the FST replaced in Lucene. There are plenty of references to the improvement. On Fri, Jun 8, 2012 at 3:50 PM, Pavel Yaskevich wrote: > I would vote, if possible, to compare it with y-fast trie [1] (it doesn't > seem to be available java implementation unfortunately) by means of memory > efficiency and lookup performance. As we use big integer tokens the main > benefit from that trie could be O(log log M) predecessor lookup and compact > in-memory size. > > [1] https://en.wikipedia.org/wiki/Y-fast_trie > > Best Regards > -- > Pavel Yaskevich > > > On Friday 8 June 2012 at 22:19, Jason Rutherglen wrote: > > > Ok looks like the IndexSummary encapsulates everything, I can start with > > hacking that. > > > > On Fri, Jun 8, 2012 at 11:50 AM, Jason Rutherglen < > > jason.rutherg...@gmail.com (mailto:jason.rutherg...@gmail.com)> wrote: > > > > > The Cassandra integration is probably beyond the time I have available. > > > If the locations in the code that need to be rewritten to use the FST > are > > > known, and a patch simply 'plugs-in' the FST, that would be much > easier. > > > Eg, I don't know how Cassandra stores the current key index for > example... > > > > > > Basically I can write FST serializing, deserializing, and key lookup > code > > > fairly easy by basing it on Lucene's terms dict. > > > > > > > > > On Fri, Jun 8, 2012 at 6:00 AM, Radim Kolar h...@filez.com)> wrote: > > > > > > > > > > > If you are interested I can help, I used the FST on a Hadoop project > > > > > to implement a fast map side range join. > > > > > > > > create JIRA item with patch attached, i will test it. > > > > > > > > > > > > > > > > > > >
Re: Cassandra in memory key index
Yeah, that is why I wrote "if possible" :) Also, does FST provide a predecessor lookup function, wasn't clear from the blog post? On Friday 8 June 2012 at 22:53, Jason Rutherglen wrote: > Yeah that's fine, however if there isn't a Java implementation that's a lot > of extra work. The FST approach should be a clear quick and easy win. The > current system of in heap keys and a binary search is what the FST replaced > in Lucene. There are plenty of references to the improvement. > > On Fri, Jun 8, 2012 at 3:50 PM, Pavel Yaskevich (mailto:pove...@gmail.com)> wrote: > > > I would vote, if possible, to compare it with y-fast trie [1] (it doesn't > > seem to be available java implementation unfortunately) by means of memory > > efficiency and lookup performance. As we use big integer tokens the main > > benefit from that trie could be O(log log M) predecessor lookup and compact > > in-memory size. > > > > [1] https://en.wikipedia.org/wiki/Y-fast_trie > > > > Best Regards > > -- > > Pavel Yaskevich > > > > > > On Friday 8 June 2012 at 22:19, Jason Rutherglen wrote: > > > > > Ok looks like the IndexSummary encapsulates everything, I can start with > > > hacking that. > > > > > > On Fri, Jun 8, 2012 at 11:50 AM, Jason Rutherglen < > > > jason.rutherg...@gmail.com (mailto:jason.rutherg...@gmail.com)> wrote: > > > > > > > The Cassandra integration is probably beyond the time I have available. > > > > If the locations in the code that need to be rewritten to use the FST > > > > > > > > > > > > > > are > > > > known, and a patch simply 'plugs-in' the FST, that would be much > > > > > > > easier. > > > > Eg, I don't know how Cassandra stores the current key index for > > > > > > > example... > > > > > > > > Basically I can write FST serializing, deserializing, and key lookup > > code > > > > fairly easy by basing it on Lucene's terms dict. > > > > > > > > > > > > On Fri, Jun 8, 2012 at 6:00 AM, Radim Kolar > > > (mailto:h...@filez.com) (mailto: > > h...@filez.com (mailto:h...@filez.com))> wrote: > > > > > > > > > > > > > > If you are interested I can help, I used the FST on a Hadoop project > > > > > > to implement a fast map side range join. > > > > > > > > > > > > > > > create JIRA item with patch attached, i will test it.
Re: Cassandra in memory key index
Dne 8.6.2012 21:19, Jason Rutherglen napsal(a): Ok looks like the IndexSummary encapsulates everything, I can start with hacking that. do memory part first. i want to test it on existing serialized index data.
