Re: how does cassandra compare with mongodb?

On Thu, May 13, 2010 at 7:31 PM, Steve Lihn wrote: > Not sure how to comment on this concept. I guess it infers that the database > and application are no longer loosely coupled, but now strongly coupled. > I guess too, that java developers will vote yes, while database architect > and DBA will vo

Re: how does cassandra compare with mongodb?

Not sure if this was mentioned, but MongoDB is strongly consistent while Cassandra is eventually consistent -- at least about a month ago when I looked at it in more detail, though with vector clocks in 0.7, this may be less of an issue. As for "schema-less" and coupling of database/application, e

Re: how does cassandra compare with mongodb?

On 2010-05-13 19:48, Steve Lihn wrote: > Now the java community is developing a database like Mongo that is > schema-less. Mongo is written in C++. -- David Strauss | da...@fourkitchens.com Four Kitchens | http://fourkitchens.com | +1 512 454 6659 [office] | +1 512 870 8453 [direct]

Re: how does cassandra compare with mongodb?

> Not sure if this was mentioned, but MongoDB is strongly consistent while > Cassandra is eventually consistent -- at least about a month ago when I > looked at it in more detail, though with vector clocks in 0.7, this may be > less of an issue. Did Mongo switch away from the "fsync() every now an

Re: how does cassandra compare with mongodb?

Thanks for pointing this out. My fault in thinking Mongo is another java-based database, which I will probably realize wrong when I attend the mongo conference in a week. On Fri, May 14, 2010 at 4:45 AM, David Strauss wrote: > On 2010-05-13 19:48, Steve Lihn wrote: > > Now the java community is d

Timeouts running batch_mutate

Hey, I'm running a map/reduce job, reading from HDFS directory, and reducing to Cassandra using the batch_mutate method. The reducer builds the list of rowmutations for a single row, and calls batch_mutate at the end. As I move to a larger dataset, i'm seeing the following exception: Caused by:

cannot loadbalance node

Hello! When I am trying to run loadbalance, I got the following error message: [r...@cas2 bin]# sh nodetool -h localhost loadbalance Exception in thread "main" java.lang.UnsupportedOperationException: data is currently moving to this node; unable to leave the ring I am actually run loadbalanc

is cassandra really a 'handsoff' solution once setup?

realizing cassandra might be a little tricky to setup at first due to lack of docs etc. Once it is up and running/humming, is it a hands-off solution or does it require hand-holding/monitoring? I recall Joe Stump's blog post stating that it doesn't require an admin (or somethign to that effect wh

Re: is cassandra really a 'handsoff' solution once setup?

On May 14, 2010, at 12:46 PM, S Ahmed wrote: > For those with live apps, how has it been? (fb/digg/twitter people, would > love your experiences) I didn't say it didn't require *any* administration. Just that it required *minimal* administration. I'd say we spend about a quarter of an engineer

Re: is cassandra really a 'handsoff' solution once setup?

On Fri, May 14, 2010 at 11:46 AM, S Ahmed wrote: > realizing cassandra might be a little tricky to setup at first due to lack > of docs etc. > Once it is up and running/humming, is it a hands-off solution or does it > require hand-holding/monitoring? > I recall Joe Stump's blog post stating that i

Avro Example Code

Does anyone have a good link or example code that we can use to spike on Avro with Cassandra? Cheers.

Re: Avro Example Code

Be warned: avro support is experimental and incomplete. The avro system tests are probably the best place to start looking. http://svn.apache.org/repos/asf/cassandra/trunk/test/system Gary. On Fri, May 14, 2010 at 15:52, David Wellman wrote: > Does anyone have a good link or example code that w

Re: Avro Example Code

My Avro quickstart has an RPC example for various languages http://bit.ly/32T6Mk Patrick On 05/14/2010 01:52 PM, David Wellman wrote: Does anyone have a good link or example code that we can use to spike on Avro with Cassandra? Cheers.

Re: how does cassandra compare with mongodb?

Great thread -- thanks for pointing it out! I was referencing consistency without considering durability but that is probably something that should not be overlooked, or if it is, as you suggested, be overlooked as a conscious decision to take on risk. 2010/5/14 Peter Schüller > > Not sure if

Re: is cassandra really a 'handsoff' solution once setup?

On May 14, 2010, at 1:13 PM, Ryan King wrote: > I wouldn't use it (at least at our scale) without engineers willing to > run a java debugger. :) +1 We spend a lot of time hacking on the internals (Mike Malone and Derek Smith on the list can chime in further here). But, we have had little issue

cassandra cluster (2 node): one node is OK, another has this error: java.lang.AssertionError: invalid response count 2

Hi, Guys, I have a lasted cassandra -0.6.0.-rc1. Connect one node1 from java. Node 1 is OK, node 2 has this error: (if Connect one node2 from java. Node 2 is OK, node 1 has same error): I have checked node 1 node1 node2 node1 I have checked node2 node2 node1

cassandra error

when starting cassandra, there is "Keys must be written in ascending order." error. and, when my application reads the datastore, it throws outofmemory exception. what causes this error? how should I go about to fix the problem? thanks, -aj INFO 15:55:19,713 Creating new commitlog segment C:\de

Re: Overfull node

I've somehow now ended up in a very strange place... If I ask '150' or '155' about the ring they report each other, but if I ask the rest of the ring they have '155' but not '150' as members. All of the storage-conf files are basically clones of each other with the same ring masters. $ node

chiton

I'm having problems installing chiton... on ubuntu 9.10 I'm getting the following: Traceback (most recent call last): File "chiton/bin/chiton-client", line 2, in from twisted.internet import gtk2reactor ImportError: No module named twisted.internet does chiton work on windows?

Re: chiton

hmm...I installed that already like so: sudo apt-get install python-twisted is there anything else i need to do after that? On Fri, May 14, 2010 at 9:14 PM, Jonathan Holloway wrote: > Sounds like you need to install the twisted module for Python: > See > http://twistedmatrix.com/trac/wiki/Downl

Re: chiton

Sounds like you need to install the twisted module for Python: See http://twistedmatrix.com/trac/wiki/Downloads for the Windows/Ubuntu binaries. Hope that helps, Jon. On 14 May 2010 21:04, Sonny Heer wrote: > I'm having problems installing chiton

Re: chiton

You have to make sure that you have got twisted on your Pythonpath. Find where your site-packages are and ensure that it is in there: $ python -c "from distutils.sysconfig import get_python_lib; print get_python_lib()" Ensure that there is a symbolic link or the module is in your site-packages. Y

FileNotFoundException in ROW-READ-STAGE

One of our Cassandra nodes is throwing multiple of these errors: ERROR [ROW-READ-STAGE:185] 2010-04-27 14:56:59,543 CassandraDaemon.java (line 78) Fatal exception in thread Thread[ROW-READ-STAGE:185,5,main] java.lang.RuntimeException: java.io.FileNotFoundException: /data/cassandra/data/Onespot/Ent