KeysCached - clarification and recommendations on settings

Greetings, I would like to check my understanding is accurate on how KeysCached is understood by Cassandra (0.6.5), and then get some suggestions on settings / OS FS cache interplay. First - my initial understanding was that if you set KeysCached to 100%, Cassandra would do a best effort to

TimeUUID makes me crazy

I am getting crazy using TimeUUID in cassandra via Java. I've read the FAQ but it didn't help. Can I use a TimeUUID as ROW identifier? (if converted to string) I have a CF like this and SCF like these: TIMEUUID OPECID (ROW) { phone: 123 address: street xyz } String U

Re: Cassandra security model? ( or, authentication docs ?)

On Sun, 2010-10-17 at 21:26 -0700, Yang wrote: > I searched around, it seems that this is not clearly documented yet; > the closest I found is: > http://www.riptano.com/docs/0.6.5/install/auth-config > http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Authentication-td5285013.html#a5

Re: Read Latency

It is much faster again, but the last 3 seconds still linger. There a lot more logout complete messages getting logged all of the time, but the one below matches in time to the time the client registers it takes to get the data back. It also produces errors sometimes...the error example is listed b

Re: KeysCached - clarification and recommendations on settings

AFAIK the caches do not expire entries under memory pressure, they just hold the number of entries you specify or are unbound in the case of 100%. The caches is based on the ConcurrentLinkedHashMap (http://code.google.com/p/concurrentlinkedhashmap/) and uses the SecondChance eviction policy. " to k

Re: TimeUUID makes me crazy

Whats the call stack for the error and what client you using ? Is the error client side or server side? Is there an error in the server side log?My guess is there is something wrong in the way your are creating the UUID for the colum and super column names, rather than for the key. You can use UUID

Re: KeysCached - clarification and recommendations on settings

Also have a read of this slide deck from Ben Black, caches are talked about from slide 35 onhttp://www.slideshare.net/driftx/cassandra-summit-2010-performance-tuningThere is also a video linked here http://www.riptano.com/blog/slides-and-videos-cassandra-summit-2010AaronOn 19 Oct, 2010,at 09:10 AM,

Re: Read Latency

v3 attached to fix assertion failure. Those last seconds after "sending to client" aren't fixable except perhaps by using a faster client language. That is, the client is probably doing read-and-deserialize as one step rather than 2, so being slow in the deserialize part means the server is sitti

Re: Read Latency

v3 attached to fix assertion failure. Those last seconds after "sending to client" aren't fixable except perhaps by using a faster client language. That is, the client is probably doing read-and-deserialize as one step rather than 2, so being slow in the deserialize part means the server is sitti

Re: KeysCached - clarification and recommendations on settings

> Is your entire keyset active? If not set a sane starting point (default for > key cache is 200,000 http://wiki.apache.org/cassandra/StorageConfiguration ) >  and see what the cache hit's are like. How many keys do you have? What > was your hit rate with 100% key cache? Also, keep in mind that th

Re: KeysCached - clarification and recommendations on settings

On Mon, Oct 18, 2010 at 3:21 PM, Aaron Morton wrote: > Also have a read of this slide deck from Ben Black, caches are talked about > from slide 35 on > > http://www.slideshare.net/driftx/cassandra-summit-2010-performance-tuning > > There is also a video linked here > http://www.riptano.com/blog/sl

Thift version

Dear all, Which Thrift version does Cassandra 0.66 using? Thank a lot for support. -- Best regards, JKnight

Re: Thift version

Check the source distro's lib directory - http://svn.apache.org/repos/asf/cassandra/tags/cassandra-0.6.6/lib/ - it has libthrift-r917130.jar - so it's a build of thrift with revision 917130 of thrift. There has been talk of stabilizing on a release of thrift, but that's not yet established. G

Re: KeysCached - clarification and recommendations on settings

The lack of swearing did seem odd. AaronOn 19 Oct, 2010,at 12:41 PM, Brandon Williams wrote:On Mon, Oct 18, 2010 at 3:21 PM, Aaron Morton wrote: Also have a read of this slide deck from Ben Black, caches are talked about from slide 35 onhttp://www.slideshare.net/driftx/c

What is the correct way of changing a partitioner?

Hi, I deleted all the data (programmatically). Then I changed the partitioner from RandomPartitioner to OrderPreservingPartitioner and when I started Cassandra - I get the following error. What is the correct way of changing the partitioner and how can I get past this error? ERROR 17:28:28,985 Fat

Re: Preventing an update of a CF row

kannan chandrasekaran yahoo.com> writes: > Hi All,I have a query regarding the insert operation. The insert operation by default  inserts an new row or updates an existing row. Is it possible to prevent an update but allow only inserts automatically  ( especially when multiple clients are writing

RE: Preventing an update of a CF row

Nice and simple! -Original Message- From: Oleg Anastasyev [mailto:olega...@gmail.com] Sent: Tuesday, October 19, 2010 9:00 AM To: user@cassandra.apache.org Subject: Re: Preventing an update of a CF row kannan chandrasekaran yahoo.com> writes: > Hi All,I have a query regarding the inser

Re: What is the correct way of changing a partitioner?

http://wiki.apache.org/cassandra/DistributedDeletes >From the http://wiki.apache.org/cassandra/StorageConfiguration page: > Achtung! Changing this parameter requires wiping your data directories, > since the partitioner can modify the !sstable on-disk format. So delete your data and commit log