Re: Is SuperColumn necessary?
On Thu, May 6, 2010 at 11:10 PM, Mike Malone wrote: > > The upshot is, the Cassandra data model would go from being "it's a nested > dictionary, just kidding no it's not!" to being "it's a nested dictionary, > for serious." Again, these are all just ideas... but I think this > simplified > data model would allow you to express pretty much any query in a graph of > simple primitives like Predicates, Filters, Aggregations, Transformations, > etc. The indexes would allow you to cheat when evaluating certain types of > queries - if you get a SlicePredicate on an indexed "thingy" you don't have > to enumerate the entire set of "sub-thingies" for example. > > This would be my dream implementation. I'm working an an application that needs that sort of capability. SuperColumns lead you to thinking that should be done in the cassandra tier but then fall short, so my thought was that I was just going to do everything that was in Cassandra as regular columnfamilies and columns using composite keys and composite column names ala the code I shared above, and then implement the n-level hierarchy in the app tier. It looks like your suggestion is to take it in the other direction and make it part of the fundamental data model, which would be very useful if it could be made to work without big tradeoffs.
column family naming restrictions?
Are the restrictions on column family names specified anywhere? I see that hyphens aren't allowed, and I assume anything else that wouldn't work in a filename? I assume that underscores, commas, and periods are allowed? Thanks Ed
Re: Secondary Index Operators
Interesting, I can't comment on the applicability of msgpack within Cassandra, but I posted something a while back about a serialization technique I was using for implementing inverted indexes at the application level on top of Cassandra (http://github.com/edanuff/CassandraCompositeType). I used a very primitive serialization scheme, I'll have to take a closer look at msgpack. On Sun, Jul 11, 2010 at 9:12 AM, Thomas Heller wrote: > Hey, > > I was wondering what your plans are concerning secondary indexes and > supported operators? > > I looked over the code and so far there is only EQ which of course is > the easiest since it just compares byte values and that will work for > (almost) everything. Most index operations will however require > de-serializing the data. > > I chose msgpack binaries to store my data because it was the most > compact and it keeps basic type information intact (string, int, > floats, arrays, etc), but a msgpack int is not 4 bytes and wouldnt be > castable to a standard 4 byte int so for example a "simple less than" > wouldnt work. > > Are there any plans on this topic or is it still open to discussion? > > Cheers, > /thomas >
Question about ByteBuffer positions
Is it safe to assume that anywhere that you're provided with a ByteBuffer that it's ok to leave it's position wherever you want or should you be calling buffer.duplicate() and working with your copy of the buffer? I've tried to trace anything that calls the new method signatures in AbstractType and really couldn't tell. Ed
Cassandra last stable snapshot build as a maven artifact?
Is there a way to specify this? I only see the gzip'd files at https://builds.apache.org/job/Cassandra/lastStableBuild/, but was looking for something I could specify as a repository in my pom.xml. Ed
Re: Announcements List
I think that what's being asked for isn't so much announcements as some sort of way of communicating or summarizing roadmap. However, in practical matters, I'm not sure how this can be done in a mailing list form. Anything that gets "announced" as roadmap is either so far along that it's not roadmap anymore it's a release announcement, or it's not being announced, it's being presented as an idea for comment, in which case that's what the dev mailing list and JIRA are for. I think the right venue for this is might be a official blog for the project where direction can be discussed at a lower level than maybe it would on the Datastax blog but at a higher level summarizing where certain features are going, etc. Also, would be a place where links to useful blog posts by others in the community could be posted. Ed On Wed, Jul 20, 2011 at 9:21 AM, Jonathan Ellis wrote: > That's exactly the kind of thing that *shouldn't* be on an announce > list (and stay on the dev list), precisely because it deals with > internals that users don't care about. > > On Wed, Jul 20, 2011 at 11:18 AM, David Boxenhorn wrote: >> I would like to see this list also used for announcing upcoming features. At >> some point a decision is made that some future version will include some >> important feature. I don't want that information to be buried in a JIRA >> ticket or a user/dev list discussion. >> >> For example, I was surprised to learn, by accident, from >> http://www.slideshare.net/mattdennis/cassandra-antipatterns , that >> supercolumns will be replaced, internally, by composite columns. This is >> something that we've discussed in the past, and that I have advocated >> myself, but until now I have seen no indication that it would be done, or >> that it was even viewed favorably by a consensus of decision makers. >> >> >> On Mon, Jul 18, 2011 at 6:52 PM, Nick Bailey wrote: >> >>> DataStax has had requests for something like this. It seems like >>> something that would be generally useful for the community though. >>> >>> Regarding twitter, I'm not sure a twitter account should be required >>> to get that information. I think you can follow a twitter account as >>> an rss feed though, so that might be a solution. That and the google >>> alert or email filter solutions just seem to be introducing more >>> difficulty for anyone trying to get that information. Perhaps the >>> demand for this isn't as high as I am imagining though. >>> >>> My opinion on the list if we decide to go with that is that only >>> committers would be able to post to it and yes it would go to the >>> users list as well. >>> >>> On Mon, Jul 18, 2011 at 10:32 AM, Sylvain Lebresne >>> wrote: >>> > I have mixed feeling about that. >>> > >>> > On the one side, I agree with Gary that it doesn't add any real value. >>> > There is twitter, >>> > and we use consistent tagged subjects for release email, so it's easy >>> > to subscribe >>> > to the user list and set up a filter. >>> > >>> > That being said, I could understand that some people may find it >>> > cleaner to have a >>> > separate announce list and it is not something unheard of, so I'm ok >>> > with that if enough >>> > people thinks it's a good idea. But I think there is at least 2 >>> > questions that come along: >>> > - should it be moderated ? >>> > - should announces still be sent to the user list ? >>> > >>> > -- >>> > Sylvain >>> > >>> > On Mon, Jul 18, 2011 at 4:50 PM, Gary Dusbabek >>> wrote: >>> >> Following @cassandra on twitter or a google alert would be simple enough >>> I >>> >> think. >>> >> >>> >> Gary. >>> >> >>> >> On Mon, Jul 18, 2011 at 14:26, Nick Bailey wrote: >>> >> >>> >>> What do we think about having a separate mailing list for just >>> >>> cassandra related announcements. The main purpose being announcing new >>> >>> releases once they pass a vote and are put up on the website. I think >>> >>> there is a desire for a way to be informed when new releases are >>> >>> available without sifting through the dev or users mailing lists. >>> >>> >>> >> >>> > >>> >> > > > > -- > Jonathan Ellis > Project Chair, Apache Cassandra > co-founder of DataStax, the source for professional Cassandra support > http://www.datastax.com >
Re: Announcements List
+1 that's a great idea On Wed, Jul 20, 2011 at 10:19 AM, Jonathan Ellis wrote: > I'd love to put a "Planet Cassandra" aggregator together. > > On Wed, Jul 20, 2011 at 12:13 PM, Ed Anuff wrote: >> I think that what's being asked for isn't so much announcements as >> some sort of way of communicating or summarizing roadmap. However, in >> practical matters, I'm not sure how this can be done in a mailing list >> form. Anything that gets "announced" as roadmap is either so far >> along that it's not roadmap anymore it's a release announcement, or >> it's not being announced, it's being presented as an idea for comment, >> in which case that's what the dev mailing list and JIRA are for. >> >> I think the right venue for this is might be a official blog for the >> project where direction can be discussed at a lower level than maybe >> it would on the Datastax blog but at a higher level summarizing where >> certain features are going, etc. Also, would be a place where links >> to useful blog posts by others in the community could be posted. >> >> Ed >> >> On Wed, Jul 20, 2011 at 9:21 AM, Jonathan Ellis wrote: >>> That's exactly the kind of thing that *shouldn't* be on an announce >>> list (and stay on the dev list), precisely because it deals with >>> internals that users don't care about. >>> >>> On Wed, Jul 20, 2011 at 11:18 AM, David Boxenhorn >>> wrote: >>>> I would like to see this list also used for announcing upcoming features. >>>> At >>>> some point a decision is made that some future version will include some >>>> important feature. I don't want that information to be buried in a JIRA >>>> ticket or a user/dev list discussion. >>>> >>>> For example, I was surprised to learn, by accident, from >>>> http://www.slideshare.net/mattdennis/cassandra-antipatterns , that >>>> supercolumns will be replaced, internally, by composite columns. This is >>>> something that we've discussed in the past, and that I have advocated >>>> myself, but until now I have seen no indication that it would be done, or >>>> that it was even viewed favorably by a consensus of decision makers. >>>> >>>> >>>> On Mon, Jul 18, 2011 at 6:52 PM, Nick Bailey wrote: >>>> >>>>> DataStax has had requests for something like this. It seems like >>>>> something that would be generally useful for the community though. >>>>> >>>>> Regarding twitter, I'm not sure a twitter account should be required >>>>> to get that information. I think you can follow a twitter account as >>>>> an rss feed though, so that might be a solution. That and the google >>>>> alert or email filter solutions just seem to be introducing more >>>>> difficulty for anyone trying to get that information. Perhaps the >>>>> demand for this isn't as high as I am imagining though. >>>>> >>>>> My opinion on the list if we decide to go with that is that only >>>>> committers would be able to post to it and yes it would go to the >>>>> users list as well. >>>>> >>>>> On Mon, Jul 18, 2011 at 10:32 AM, Sylvain Lebresne >>>>> wrote: >>>>> > I have mixed feeling about that. >>>>> > >>>>> > On the one side, I agree with Gary that it doesn't add any real value. >>>>> > There is twitter, >>>>> > and we use consistent tagged subjects for release email, so it's easy >>>>> > to subscribe >>>>> > to the user list and set up a filter. >>>>> > >>>>> > That being said, I could understand that some people may find it >>>>> > cleaner to have a >>>>> > separate announce list and it is not something unheard of, so I'm ok >>>>> > with that if enough >>>>> > people thinks it's a good idea. But I think there is at least 2 >>>>> > questions that come along: >>>>> > - should it be moderated ? >>>>> > - should announces still be sent to the user list ? >>>>> > >>>>> > -- >>>>> > Sylvain >>>>> > >>>>> > On Mon, Jul 18, 2011 at 4:50 PM, Gary Dusbabek >>>>> wrote: >>>>> >> Following @cassandra on twitter or a google alert would be simple >>>>> >> enough >>>>> I >>>>> >> think. >>>>> >> >>>>> >> Gary. >>>>> >> >>>>> >> On Mon, Jul 18, 2011 at 14:26, Nick Bailey wrote: >>>>> >> >>>>> >>> What do we think about having a separate mailing list for just >>>>> >>> cassandra related announcements. The main purpose being announcing new >>>>> >>> releases once they pass a vote and are put up on the website. I think >>>>> >>> there is a desire for a way to be informed when new releases are >>>>> >>> available without sifting through the dev or users mailing lists. >>>>> >>> >>>>> >> >>>>> > >>>>> >>>> >>> >>> >>> >>> -- >>> Jonathan Ellis >>> Project Chair, Apache Cassandra >>> co-founder of DataStax, the source for professional Cassandra support >>> http://www.datastax.com >>> >> > > > > -- > Jonathan Ellis > Project Chair, Apache Cassandra > co-founder of DataStax, the source for professional Cassandra support > http://www.datastax.com >
Re: REST API?
For Usergrid, we use Jersey (http://jersey.java.net/), the Sun implementation of JAX-RS, which makes use of Jackson (http://wiki.fasterxml.com/JacksonHome) for the JSON marshalling. I'd heartily recommend using those if you're going to roll your own REST implementation in Java. If you're looking for a very high level REST API, you might want to look at Usergrid (http://github.com/usergrid/stack). We're abstracting away the underlying Cassandra representation to a pretty high degree, but it might be useful depending on what you're trying to do. Ed On Mon, Oct 10, 2011 at 6:12 PM, Brian O'Neill wrote: > My team desperately needs a REST API for Cassandra. > > I saw the following: > http://code.google.com/p/restish/ > from > http://crlog.info/2011/01/29/restish-wrapper-for-hectorcassandra-data-manipulation/ > > But it appears to have little activity and documentation. > > That lead me to start work on a contrib/rest module, but before I get to far > I wanted to ask if there was any effort underway for a REST Server/API. > If not, I'll continue developing the REST server. Any preference for a REST > stack? (JAX-RS on Apache-CXF? Raw Servlets? Netty? etc.) > > Until I hear back, I'll continue with the JAX-RS / Apache CXF implementation > I have cooking. > > -brian > > -- > Brian ONeill > Lead Architect, Health Market Science (http://healthmarketscience.com) > mobile:215.588.6024 > blog: http://weblogs.java.net/blog/boneill42/ > blog: http://brianoneill.blogspot.com/ >
