Re: Coprosessors/Triggers in C*

I understood it as a "run trigger when column gets deleted due to TTL", so - as you said - it doesn't sound like something that can be done. Gareth, TTL'd columns in Cassandra are not really removed after TTL - they are just ignored from that time (so they're not returned by queries), but they

Re: Cassandra 2.0 new features ?

Jonathan Ellis has covered it briefly in this presentation here (slide 51): http://www.slideshare.net/planetcassandra/nyc-jonathan-ellis-keynote-cassandra-12-20 They are: 1. Eager retries 2. Improved compaction 3. Triggers 4. CAS (Compare-and-set) 5. More-efficient repair Thanks,

Cassandra 2.0 new features ?

Hi All, Can anyone tell me about the new features that are going to come in Cassandra 2.0 ? Thank you Emalayan

Compaction not running

Hi, We are running a test system with Leveled compaction on Cassandra-1.2.4. While doing an initial load of the data one of the nodes ran out of file descriptors and since then it hasn't been automatically compacting. Any suggestions on how to fix this ? thanks -- *Franc Carter* | Systems arc

Re: Multiple data center performance

Sorry for the confusion. Sylvain - Do you think what could cause the client higher latency in multiDC(CL=one for read and write) ? clients only connect to nodes in the same DC. we did see the performance greatly improved after changing the replication factor for counters, but still slower than ot

Re: Multiple data center performance

Crystal clear, we use a lot of counters and I am always happy to learn this kind of things. Thanks a lot. Alain 2013/6/12 Sylvain Lebresne > > Is there something special of this kind regarding counters over multiDC ? >> > > No. Counters behave exactly as other writes as far the consistency le

Re: Multiple data center performance

> Is there something special of this kind regarding counters over multiDC ? > No. Counters behave exactly as other writes as far the consistency level is concerned. Technically, the counter write path is different from the normal write path in the sense that a counter write will be written to one

Re: Multiple data center performance

"The consistency level does *not* influence which replica are written to. Cassandra always write to all replicas." I am aware of this. My understanding of what Daning said was that client waited for all nodes to acknowledge the write before considering it successful (inducing extra latency) for c

Re: Coprosessors/Triggers in C*

I do not understand what feature you suggesting. Columns can already have a ttl. Are you speaking of a ttl column that could delete something beside itself. That does not sound easy because a ttl comment is dorment until read or compacted. On Tuesday, June 11, 2013, Gareth Collins wrote: > Hello

Re: Multiple data center performance

It is the normal behavior, but that's true of any update, not only of counters. The consistency level does *not* influence which replica are written to. Cassandra always write to all replicas. The consistency level only decides how replica acknowledgement are waited for. -- Sylvain On Wed, Jun

Re: [Cassandra] Expanding a Cassandra cluster

We run it concurrently each RF nodes (If RF = 3, we run it on 3 waves). If the node is busy cleaning up, then the client will time out and ask to an other node having a copy of the data and that is not being cleaned up. "Will node tool cleanup consume lot of IO and CPU even though there is nothing

Re: Multiple data center performance

"counter will replicate to all replicas during write regardless the consistency level" I that the normal behavior or a bug ? 2013/6/11 Daning Wang > It is counter caused the problem. counter will replicate to all replicas > during write regardless the consistency level. > > In our case. we don