Re: Replacing Redis

2011-02-20 Thread Benson Margulies
Thanks for replying, but it is not at all clear to me that redis was ever the right solution to the problem at hand. I'm still working out whether, in fact, Cassandra is. Up to a fairly large scale, this particular problem needs no 'cache' at all. It needs a write-behind persistence mechanism --

Re: Health of the cluster

2011-02-20 Thread Aaron Morton
Have a read of this page http://wiki.apache.org/cassandra/Operations Aaron On 18/02/2011, at 12:40 PM, mcasandra mohitanch...@gmail.com wrote: I have just started setting up Hector. I have 2 node cluster running in foreground for my test so that I can watch everything. One big question

Re: memory consuption

2011-02-20 Thread Aaron Morton
Thanks Peter for the extra detail. I thought there may have been something more mysterious going on. But it sounds like it was just the semantics of the term use. Cheers Aaron On 18/02/2011, at 9:25 PM, Peter Schuller peter.schul...@infidyne.com wrote: main argument for using mmap() instead

Re: How to use NetworkTopologyStrategy

2011-02-20 Thread Aaron Morton
The best examples I know of are in the internal cli help, and conf/casandra.yaml Aaron On 19/02/2011, at 12:51 AM, Héctor Izquierdo Seliva izquie...@strands.com wrote: Hi! Can some body give me some hints about how to configure a keyspace with NetworkTopologyStrategy via cassandra-cli? Or

Re: R and N

2011-02-20 Thread Aaron Morton
My understanding.. 1 read repair involves the coordinator sending a full data read to CL nodes, resolving the differences and sending writes back. For CL one this happens after returning, for higher CL this happens before. (my understanding of the internals of RR are a little rough though) 2

Re: frequent client exceptions on 0.7.0

2011-02-20 Thread Aaron Morton
AFAIK the MemtablePostFlusher is the TP writing sstables, if it has a queue then there is the potential for writes to block while it waits for Memtables to be flushed. Take a look at your Memtable settings per CF, could it be that all the Memtables are flushing at once? There is info in the

Re: Async write

2011-02-20 Thread Aaron Morton
AFAIK the write across the dc is sync as well. I think there I'd a ticket out there to make them asnc, take a look at Jira. Aaron On 19/02/2011, at 10:24 AM, Anthony John chirayit...@gmail.com wrote: Fact as i understand them:- - A write call to db triggers a number of async writes to all

Re: Timeout

2011-02-20 Thread Aaron Morton
Some of the schema operations wait to check agreement between the nodes before proceeding. Are there any messages in your server side logs. Aaron On 19/02/2011, at 2:47 PM, mcasandra mohitanch...@gmail.com wrote: Forgot to mention replication factor is 1 and I am running Cassandra 0.7.0.

Re: Async write

2011-02-20 Thread Jonathan Ellis
On Sun, Feb 20, 2011 at 1:36 PM, Aaron Morton aa...@thelastpickle.com wrote: On 19/02/2011, at 10:24 AM, Anthony John chirayit...@gmail.com wrote: Fact as i understand them:- - A write call to db triggers a number of async writes to all nodes where the particular write should be recorded

Re: read latency in cassandra

2011-02-20 Thread Dan Kuebrich
Thanks for the probing questions. Just got around to looking into this a bit more and discovered it's not exactly what I thought. It's actually a single multiget_slice with a fairly slow response time. I've answered as many of the questions as I can, and have also included a reply to Rob's

Re: Async write

2011-02-20 Thread Aaron Morton
Sorry, was typing faster than my brain was working.I was trying to say at the higher level the request would block for the write operations in other DC's to complete. As you say.That was the ticket I was thinking of.ThanksAaronOn 21 Feb, 2011,at 01:19 PM, Jonathan Ellis jbel...@gmail.com wrote:On

Re: Replacing Redis

2011-02-20 Thread David Strauss
On Sun, 2011-02-20 at 09:04 -0500, Benson Margulies wrote: There are two parts to the data footprint, one growing more rapidly than the other. The faster growing part has a natural 'redis-friendly' data model (keys map to values); but it would map to EHCache as well. If you're coming into the

Re: Understand eventually consistent

2011-02-20 Thread David Strauss
On Fri, 2011-02-18 at 12:01 -0600, Anthony John wrote: Writes will go thru w/hinted handoff, read will fail That is not correct. Hinted handoffs do not count toward reaching QUORUM counts.[1] [1] http://wiki.apache.org/cassandra/HintedHandoff -- David Strauss | da...@davidstrauss.net |

Re: Are row-keys sorted by the compareWith?

2011-02-20 Thread Dan Washusen
Hi Carlo, As Jonathan mentions the compareWith on a column family def. is defines the order for the columns *within* a row... In order to control the ordering of rows you'll need to use the OrderPreservingPartitioner

Broken image links in Wiki:MemtableThresholds

2011-02-20 Thread Maki Watanabe
Hello folks, I'm tranlating the Wiki pages to Japanese now. I found all of images in MemtableThresholds are broken: http://wiki.apache.org/cassandra/MemtableThresholds Can anyone fix the links? Thanks -- maki

RE: Broken image links in Wiki:MemtableThresholds

2011-02-20 Thread morishita.yuki
I think apache infra team is working on the issue... https://issues.apache.org/jira/browse/INFRA-3352 -Original Message- From: Maki Watanabe [mailto:watanabe.m...@gmail.com] Sent: Monday, February 21, 2011 1:20 PM To: user@cassandra.apache.org Subject: Broken image links in

Re: Broken image links in Wiki:MemtableThresholds

2011-02-20 Thread Maki Watanabe
Ok, I got it. 2011年2月21日13:37 morishita.y...@future.co.jp: I think apache infra team is working on the issue... https://issues.apache.org/jira/browse/INFRA-3352 -Original Message- From: Maki Watanabe [mailto:watanabe.m...@gmail.com] Sent: Monday, February 21, 2011 1:20 PM To: