Re: [SPAM] Fwd: Counter consistency - are counters idempotent?

2011-07-22 Thread Donal Zang
l a limitation of counters. If counters are not idempotent, are there examples of effective uses of counters that will prevent inconsistent counts? Thank you for your help. -- Donal Zang Computing Center, IHEP 19B YuquanLu, Shijingshan District,Beijing, 100049 zan...@ihep.ac.cn 86 010 8823 6018

Re: CompositeType for row Keys

2011-07-22 Thread Donal Zang
On 22/07/2011 17:56, Patrick Julien wrote: I can still use it for keys if I don't need ranges then? Because for what we are doing we can always re-assemble keys yes,but why would you use CompositeType if you don't need range query? On Fri, Jul 22, 2011 at 11:38 AM, Donal Zang wrot

Re: CompositeType for row Keys

2011-07-22 Thread Donal Zang
specific use case, what would work best is to have a composite key that is a CompositeType with thousands of columns each. -- Donal Zang Computing Center, IHEP 19B YuquanLu, Shijingshan District,Beijing, 100049 zan...@ihep.ac.cn 86 010 8823 6018

Re: Counter Column

2011-06-28 Thread Donal Zang
I think the default is replicate_on_write=false, you have to declare it explicitly. -- Donal Zang Computing Center, IHEP 19B YuquanLu, Shijingshan District,Beijing, 100049 zan...@ihep.ac.cn 86 010 8823 6018

Re: Counter Column

2011-06-27 Thread Donal Zang
amily. -- Donal Zang Computing Center, IHEP 19B YuquanLu, Shijingshan District,Beijing, 100049 zan...@ihep.ac.cn 86 010 8823 6018

Re: Querying superColumn

2011-06-16 Thread Donal Zang
*Employee2{* *Name: Vivs* *country: USA* *}* Now if I want to retrieve a super column whose rowkey is 'DEPT1' and employee name is 'Vivek'. Can I get only 'EMPLOYEE1' ? -- Donal Zang Computing Center, IHEP 19B YuquanLu, Shijingshan District,Beijing, 100049 zan...@ihep.ac.cn 86 010 8823 6018

Re: insert slowdown with secondary indexes

2011-06-11 Thread Donal Zang
uch faster than the secondary index. (this method may need the CompositeType [3]) [1] https://issues.apache.org/jira/browse/CASSANDRA-1472 [2] http://www.anuff.com/2010/07/secondary-indexes-in-cassandra.html [3] https://issues.apache.org/jira/browse/CASSANDRA-2231 -- Donal Zang Computing Cente

Re: [SPAM] Re: [SPAM] Re: slow insertion rate with secondary index

2011-06-06 Thread Donal Zang
On 06/06/2011 14:29, David Boxenhorn wrote: Jonathan, are Donal Zang's results (10x slowdown) typical? On Mon, Jun 6, 2011 at 3:14 PM, Jonathan Ellis <mailto:jbel...@gmail.com>> wrote: On Mon, Jun 6, 2011 at 6:28 AM, Donal Zang mailto:zan...@ihep.ac.cn>> wrote:

Re: [SPAM] Re: slow insertion rate with secondary index

2011-06-06 Thread Donal Zang
get_indexed_slices() goes time out from time to time (with pycassa.ConnectionPool('keyspace1', ['host1','host2'], timeout=600, pool_size=1) ). Does some one else have some same experiences using the secondary indexes? -- Donal Zang Computing Center, IHEP

Re: [SPAM] Re: slow insertion rate with secondary index

2011-06-06 Thread Donal Zang
load advice to ingest data prior to creating indexes applies. Thanks for the explanation! -- Donal Zang Computing Center, IHEP 19B YuquanLu, Shijingshan District,Beijing, 100049 zan...@ihep.ac.cn 86 010 8823 6018

slow insertion rate with secondary index

2011-06-05 Thread Donal Zang
I did a insertion test with and without secondary indexes, and found that: Without secondary index: ~10864 rows inserted per second With secondary index on one column(BytesType): ~1515 rows inserted per second Is this normal? why secondary index would have so much affect? I noticed that If I bu

get_indexed_slices count api

2011-05-31 Thread Donal Zang
Hi, I'm query on cassandra like "select count(*) from table where column1 = v1 and ...", based on a secondary index on column1. But using get_indexed_slices(), I have to fetch all the rows and count on them, which is not needed. So a get_indexed_slices count api [1] would be very helpful, but it

python cql driver select count(*) failed

2011-05-27 Thread Donal Zang
Hi, I'm using the jar from the trunk source code . I tried the following select cql, but it get the wrong result.(I can get the right result using pycassa's get_count()) /cqlsh> select count(1) from t_container where KEY = '2011041210' ; (0,) cqlsh> select count(*) from t_container where KEY =

when 0.8.1 will be released?

2011-05-23 Thread Donal Zang
Hi, Is there a time planed for 0.8.1 release? I want to use the CompositeType comparer : https://issues.apache.org/jira/browse/CASSANDRA-2231 Thanks! Donal

statistcs query on cassandra

2011-04-04 Thread Donal Zang
Can we do count like this? /count [:] where = / -- Donal Zang Computing Center, IHEP 19B YuquanLu, Shijingshan District,Beijing, 100049 zan...@ihep.ac.cn 86 010 8823 6018

NullPointerException with 0.7.4

2011-04-03 Thread Donal Zang
k.run(MessageDeliveryTask.java:72) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at java.lang.Thread.run(Thread.java:636) -- Donal Zang CERN PH-ADP-DDM 40-3-D16 CH-1211 Gene

apache.org down?

2011-03-03 Thread Donal Zang
rt -- Donal Zang

Re: Cassandra automatic startup script on ubuntu

2011-01-20 Thread Donal Zang
On 20/01/2011 17:51, Sébastien Druon wrote: Hello! I am using cassandra on a ubuntu machine and installed it from the binary found on the cassandra home page. However, I did not find any scripts to start it up at boot time. Where can I find this kind of script? Thanks a lot in advance Sebas

should "nodetool repair " run periodic to keep consistency?

2011-01-19 Thread Donal Zang
Just to ensure. So this should be done manually by the cluster operators? Thanks! --

Re: Between Clause

2011-01-17 Thread Donal Zang
On 17/01/2011 11:55, kh jo wrote: What is the best way to model a query with between clause.. given that you have a large number of entries... thanks Jo In my experience,for the row based 'between clause' with a random partition, you should design the column family carefully, So that you

OOM error while startup cassandra0.7.0 rc1

2010-12-14 Thread Donal Zang
hi, I'm using apache-cassandra-0.7.0-rc1, and use java 1.6.0_17. The node collapse because of java.lang.OutOfMemoryError: Java heap space, and now it can't be restarted, becuase every time when it's replay the commit-logs, it will collapse by OOM error. I have 4G memory and I tried to set the bi

Can super column family use column_metadata?

2010-12-07 Thread Donal Zang
Hi, I'm using 0.7.0-rc1,and when I use cassandra-cli to create a column family with metadata, I got "null",and no column family is created. The command I use is: /create keyspace test; use test; create column family test1 with column_type = 'Super' and comparator = 'LongType' and column_metada

how to see how many rows in each node?

2010-12-03 Thread Donal Zang
RT. Is there any command or api? Thanks!