Re: Consequences of having many columns

Currently there is a limitation that each row must fit in memory (with some not insignificant overhead), thus having lots of columns per row can trigger out-of-memory errors. This limitation should be removed in a future release. Please see: - http://wiki.apache.org/cassandra/CassandraLimitation

Re: Cluster performance degrades if any single node is slow

On Wed, Jul 7, 2010 at 11:33 AM, Jonathan Ellis wrote: > Having a few requests time out while the service detects badness is > typical in this kind of system. I don't think writing a completely > separate StorageProxy + supporting classes to allow avoiding this in > exchange for RF times the net

Cluster performance degrades if any single node is slow

We've been experiencing some cluster-wide performance issues if any single node in the cluster is performing poorly. For example this occurs if compaction is running on any node in the cluster, or if a new node is being bootstrapped. We believe the root cause of this issue is a performance optimiz

Re: Cassandra disk space utilization

Hi Julie -- Keep in mind that there is additional data storage overhead, including timestamps and column names. Because the schema can vary from row to row, the column names are stored with each row, in addition to the data. Disk space-efficiency is not a primary design goal for Cassandra. Mason

Re: FileNotFoundException in ROW-READ-STAGE

Grepping through the logs, I haven't been able to deduce what was going on at the same time, but I have found many instances of these errors for multiple files going back for weeks nows. (Found 848 of these errors since 4-23-2010). The files not found include Index and Data files spanning multiple

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

Re: Does anybody work about transaction on cassandra ?

done some exploring: http://codemonkeyism.com/cassandra-scala-akka/ [1] http://en.wikipedia.org/wiki/Software_transactional_memory [2] http://doc.akkasource.org/ Mason Hale http://www.onespot.com On Thu, Apr 22, 2010 at 9:14 AM, Miguel Verde wrote: > No, as far as I know no one is working o

Re: Regarding Cassandra Scalability

On Sun, Apr 18, 2010 at 8:26 AM, Brandon Williams wrote: > > On Sun, Apr 18, 2010 at 8:00 AM, Mason Hale wrote: > >> This is a statement I wish I had run across sooner. Our first >> implementation (which we're changing now) included some very big rows. We >> ran

Re: Regarding Cassandra Scalability

On Sun, Apr 18, 2010 at 7:41 AM, Gary Dusbabek wrote: > On Sat, Apr 17, 2010 at 10:50, dir dir wrote: > > > > What problems can’t it solve? > > > > No flexible indices > > No querying on non PK values > > Not good for binary data (>64mb) unless you chunck > > Row contents must fit in available m

Re: Regarding Cassandra Scalability

On Sat, Apr 17, 2010 at 10:50 AM, dir dir wrote: > Hi Mason, > > Honestly, I am beginner user in Cassandra. I rather confused to follow > this database. I ask to the forum about the reason twitter.com to use > Cassandra > because I want to know the basic reason why we choose Cassandra instead of

Re: Regarding Cassandra Scalability

Twitter who made this decision can really explain the rationale behind it. This link should shed some light on the subject: http://engineering.twitter.com/2010/02/link-cassandra-at-twitter.html Mason -- Mason Hale http://www.onespot.com direct +1 800.618.0768 ext 701

How to model 2D data in Cassandra?

ty. No geometry calulations required. ;-) This page provides a good description of the technique: http://code.google.com/apis/maps/articles/geospatial.html Mason -- Mason Hale http://www.onespot.com direct +1 800.618.0768 ext 701