Re: 2014 nosql benchmark

Today I've also seen this benchmark in Chinese websites. "SequoiaDB" seems come from a Chinese startup company, and in db-engines ranking it's score is 0.00. So IMO I have to say I think this benchmark is a "soft sell". They compare three databases, two written by

Re: full gc too often

han the query for a single column. Is there any testing result for the relationship between the "pressure" and the "safety" heap size? We know query a slice with many tombstones is not a good use case, but query a slice without tombstones may be a common use case, right? >

Re: full gc too often

Yang 2014-12-05 12:34 GMT+08:00 Tim Heckman : > On Dec 4, 2014 8:14 PM, "Philo Yang" wrote: > > > > Hi,all > > > > I have a cluster on C* 2.1.1 and jdk 1.7_u51. I have a trouble with full > gc that sometime there may be one or two nodes full gc more than o

full gc too often

ine without gc trouble. Can anyone help me to find out where is the problem that full gc can't reduce CMS Old Gen? Is it because there are too many objects in heap can't be recycled? I think review the table scheme designing and add new nodes into cluster is a good idea, but I still want to know if there is any other reason causing this trouble. Thanks, Philo Yang

RangeTombstoneList.diff AssertionError in 2.1.0

(SEPWorker.java:103) [apache-cassandra-2.1.0.jar:2.1.0] at java.lang.Thread.run(Thread.java:744) [na:1.7.0_51] I have also posted this issue on JIRA <https://issues.apache.org/jira/browse/CASSANDRA-8013> Thanks, Philo Yang

Re: why bloom filter is only for row key?

Thanks Rob Thanks, Philo Yang 2014-09-16 2:12 GMT+08:00 DuyHai Doan : > Nice catch Rob > > On Mon, Sep 15, 2014 at 8:04 PM, Robert Coli wrote: > >> On Sun, Sep 14, 2014 at 11:22 AM, Philo Yang wrote: >> >>> After reading some docs, I find that bloom filter

Re: why bloom filter is only for row key?

loom filter's property between row keys and row keys+column names automatically or by user's config? Thanks, Philo Yang 2014-09-15 2:45 GMT+08:00 DuyHai Doan : > Hello Philo > > Building bloom filter for column names (what you call column key) is > technically possible but

why bloom filter is only for row key?

on? Thanks, Philo Yang

Re: Best practices for frequently updated columns

) to cache the read request. Write into C* and redis both and read only from redis for the latest bar. Read from C* for previous bars if the memory size is bottleneck. Thanks, Philo Yang 2014-08-14 2:13 GMT+08:00 Robert Coli : > On Wed, Aug 13, 2014 at 8:01 AM, Jeremy Jongsma > wrote: >

select many rows one time or select many times?

nd select 1000 times? just like: select from word where user='someuser' and word = 'a'; select from word where user='someuser' and word = 'b'; select from word where user='someuser' and word = 'c'; . Which method will cause lower pressure on Cassandra cluster? Thanks, Philo Yang

Re: "ghost" table is breaking compactions and won't go away… even during a drop.

work... Thanks, Philo Yang 2014-07-17 10:32 GMT+08:00 Kevin Burton : > you rock… glad it's fixed in 2.1… :) > > > > > On Wed, Jul 16, 2014 at 7:05 PM, graham sanderson wrote: > >> Known issue deleting and recreating a CF with the same name, fixed in 2.1 >&

Is "timestamp" a reserved word in CQL?

s automatically. Is "timestamp" a reserved word in CQL? I'm using Cassandra 2.0.6. Thanks, Philo Yang

How to deal with SSTable FileNotFoundException?

Hi all, I have a Cassandra 2.0.6 cluster with 12 nodes. I find in some nodes' system.log, there are many RuntimeException such like: java.lang.RuntimeException: java.io.FileNotFoundException: /disk4/cassandra/data/{keyspace}/{cfname}/{keyspace}-{cfname}-jb-87-Data.db (No such file or directory) I