Re: CompositeType for row Keys

Why do you need another CF? Is there something wrong with repeating the key as a column and indexing it? On Fri, Jul 22, 2011 at 7:40 PM, Patrick Julien wrote: > Exactly. In any case, I just answered my own question. If I need > range, I can just make another column family where the column nam

Cassandra 0.7.8 and 0.8.1 fail when major compaction on 37GB database

Hi, Please help me with my problem. For better performance i turn off compaction and run massive inserts, after database reach 37GB i stop massive inserts and start compaction with "NodeTool compaction Keyspace CFamily". after half hour of work cassandra fall with error "Out of memory" i give 150

Re: After column deletion cassandra won't insert more data to a specific key

Remember the cli uses microsecond precision . so if your app is not using the same precision weird this will result in clients writing the biggest timsetamp winning the final value. On Saturday, July 23, 2011, Jonathan Ellis wrote: > You must have given it a delete timestamp in the "future." > >

Re: Cassandra 0.7.8 and 0.8.1 fail when major compaction on 37GB database

On Sunday, July 24, 2011, lebron james wrote: > Hi, Please help me with my problem. For better performance i turn off compaction and run massive inserts, after database reach 37GB i stop massive inserts and start compaction with "NodeTool compaction Keyspace CFamily". after half hour of work cas

Re: Cassandra 0.7.8 and 0.8.1 fail when major compaction on 37GB database

From experience with similar-sized data sets, 1.5GB may be too little. Recently I bumped our java HEAP limit from 3GB to 4GB to get past an OOM doing a major compaction. Check "nodetool -h localhost info" while the compaction is running for a simple view into the memory state. If you can, al

RE: do I need to add more nodes? minor compaction eat all IO

Jonathan, Are you sure that the reads done for compaction are sequential with Cassandra 0.6.13? This is not what I am observing right now. During a minor compaction I usually observe ~ 1500 to 1900 r/s while rMB/s is barely around 30 to 35MB/s. Just asking out of curiosity. FR -Origina

Re: Little problems with Solandra

Do I need to install Tomcat? Maybe that is the problem... On Sat, Jul 23, 2011 at 12:03 PM, Jean-Nicolas Boulay Desjardins wrote: > How is it called in the "ps"? > > Because I have a strong feeling that it tries to load... But for some > reason that is be on me it does not. > > Is there a log fil

Re: do I need to add more nodes? minor compaction eat all IO

It's sequential per-sstable. If you are compacting a lot of sstables how closely this approximates "completely sequential" will deteriorate. On Sun, Jul 24, 2011 at 1:18 PM, Francois Richard wrote: > Jonathan, > > Are you sure that the reads done for compaction are sequential with Cassandra > 0

Re: Predictable low RW latency, SLABS and STW GC

Restarting the service will drop all the memmapped caches, cassandra caches are saved / persistent and you can also use memcachd if you want. Are you experiencing stop the world pauses? There are some things that can be done to reduce the chance of them happening. Cheers - Aa

Re: CL=N-1?

Sounds like you want RF == N more than CL == N-1. You could create a separate KS with RF == N and then just write at CL = QUORUM, the write will be sent to every UP replica. For background: The System Keyspace uses the o.a.c.locator.LocalStrategy that *only* stores data on the node the mutatio

Re: Counter consistency - are counters idempotent?

What's your use case ? There are people out there having good times with counters, see http://www.slideshare.net/kevinweil/rainbird-realtime-analytics-at-twitter-strata-2011 http://www.scribd.com/doc/59830692/Cassandra-at-Twitter Cheers - Aaron Morton Freelance Cassandra Develop

Re: question on setup for writes into 2 datacenters

Quick reminder, with RF == 2 the QUORUM is 2 as well. So when using LOCAL_QUORUM with RF 2+2 you will effectively be using LOCAL_ALL which may not be what you want. As De La Soul sang, 3 is the magic number for minimum fault tolerance (QUORUM is then 2). Cheers - Aaron Morto

Re: "select * from A join B using(common_id) where A.id == a and B.id == b "

> my fall-back approach is, since A and B do not change a lot, I'll > pre-generate the join of A and B (not very large) keyed on A.id + > B.id, > then do the get(a+b) +1 materialise views / joins you know you want ahead of time. Trade space for time. Cheers - Aaron Morton Freel

host clocks

hi all, I'm launching a cassandra cluster with 30 nodes. I wonder whether the inconsistency of host clocks will influence the performance of cluster. Thanks!

Some commit logs not deleting

Hello, We are running Cassandra 0.7.5 on a 15 node cluster, RF=3. We are having a problem where some commit logs do not get deleted. Our write load generates a new commit log about every two to three minutes. On average, one commit log an hour is not deleted. Without draining, deleting the remaini

Re: host clocks

You should always sync your host clocks. Clients provide timestamp but for the server gc_grace and ttl columns can have issues if server clocks are not correct. On Sunday, July 24, 2011, 魏金仙 wrote: > hi all, >I'm launching a cassandra cluster with 30 nodes. I wonder whether the inconsistency