R: Re: Migration from 0.7 to 1.0

2012-01-05 Thread cbert...@libero.it
Aaron first of all thanks for your great support. I'm paranoid, so I would upgrade 1 node and let it soak in for a few hours. Nothing like upgrading an entire cluster and then discovering a problem. Ok but as far as my application is concerned is safe to keep a cluster with part

Re: Should I throttle deletes?

2012-01-05 Thread aaron morton
I use a batch mutator in Pycassa to delete ~1M rows based on a longish list of keys I'm extracting from an auxiliary CF (with no problem of any sort). What is the size of the deletion batches ? Now, it appears that such heads-on delete puts a temporary but large load on the cluster. I have

Writes slower then reads

2012-01-05 Thread R. Verlangen
Hi there, I'm running a cassandra 0.8.6 cluster with 2 nodes (in 2 DC's), RF = 2. Actual data on the nodes is only 1GB. Disk latency 1ms. Disk throughput ~ 0.4MB/s. OS load always below 1 (on a 8 core machine with 16GB ram). When I'm running my writes against the cluster with cl = ONE all reads

Re: Writes slower then reads

2012-01-05 Thread Philippe
What can you see in vmstat/dstat ? Le 5 janv. 2012 11:58, R. Verlangen ro...@us2.nl a écrit : Hi there, I'm running a cassandra 0.8.6 cluster with 2 nodes (in 2 DC's), RF = 2. Actual data on the nodes is only 1GB. Disk latency 1ms. Disk throughput ~ 0.4MB/s. OS load always below 1 (on a 8

Re: Writes slower then reads

2012-01-05 Thread R. Verlangen
As I posted this I noticed that the other node's CPU is running high on some other cronjobs (every couple of minutes to 60% usage). Is the lack of more CPU cycles a problem in this case? Robin 2012/1/5 R. Verlangen ro...@us2.nl CPU is idle ( 10% usage). Disk reads occasionally blocks over

Re: Consistency Level

2012-01-05 Thread aaron morton
I missed a ! in the code :) The query will break the token ring into ranges based on the node tokens and then find the UP nodes for each range. I've taken another walk through the code, the logs helped. In short, you do not have enough UP nodes to support an indexed get at CL ONE. It is

Re: is it bad to have lots of column families?

2012-01-05 Thread aaron morton
Sort of. Depends. In Cassandra automatic memory management means the server can support more CF's and it has apparently been tested to 100's or 1000's of CF's. Having lots of CF's will impact performance by putting memory and IO under pressure though. If you have 10's you should not have to

Re: Migration from 0.7 to 1.0

2012-01-05 Thread aaron morton
Ok but as far as my application is concerned is safe to keep a cluster with part of 1.0 and part of 0.7? I *think* it should be so long as it's a short time and you do not run any repairs. If 1.0 creates any new files, via mutations or compaction, they will not be readable by 0.7. So the

Re: emptying my cluster

2012-01-05 Thread Alexandru Sicoe
Hi, On Wed, Jan 4, 2012 at 9:54 PM, aaron morton aa...@thelastpickle.comwrote: Some thoughts on the plan: * You are monkeying around with things, do not be surprised when surprising things happen. I am just trying to explore different solutions for solving my problem. * Deliberately

Composite column docs

2012-01-05 Thread Shimi Kiviti
Is there a doc for using composite columns with thrift? Is https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/db/marshal/CompositeType.java the only doc? does the client needs to add the length to the get \ get_slice... queries or is it taken care of on the server side?

Re: is it bad to have lots of column families?

2012-01-05 Thread Philippe
My 0.8 production cluster contains around 150 CFs spread across 5 keyspaces. Haven't found that to be an issue (yet?). Some of them are huge (dozens of GB), some are tiny (some MB). Cheers 2012/1/5 aaron morton aa...@thelastpickle.com Sort of. Depends. In Cassandra automatic memory

Re: Writes slower then reads

2012-01-05 Thread Philippe
Depending on the CL you're reading at it will yes : if the CL requires that the slow node create a digest of the data and send it to the coordinator then it might explain the poor performance on reads. What is your read CL ? 2012/1/5 R. Verlangen ro...@us2.nl As I posted this I noticed that the

Re: Writes slower then reads

2012-01-05 Thread R. Verlangen
I'm also reading with CL = ONE 2012/1/5 Philippe watche...@gmail.com Depending on the CL you're reading at it will yes : if the CL requires that the slow node create a digest of the data and send it to the coordinator then it might explain the poor performance on reads. What is your read CL

Re: Writes slower then reads

2012-01-05 Thread Philippe
What if you shutdown the cassandra service on the slow node, does that improve your read performance ? If it does then that sole node is responsible for the slow down because it can't act as a coordinator fast enough. 2012/1/5 R. Verlangen ro...@us2.nl I'm also reading with CL = ONE 2012/1/5

Re: Writes slower then reads

2012-01-05 Thread R. Verlangen
It does not appear to affect the response time, certainly not in a positive way. 2012/1/5 Philippe watche...@gmail.com What if you shutdown the cassandra service on the slow node, does that improve your read performance ? If it does then that sole node is responsible for the slow down because

Re: Writes slower then reads

2012-01-05 Thread Philippe
You may be overloading the cluster though... My hypothesis is that your traffic is being spread across your node and that one slow node is slowing down the fraction of traffic that goes to that node (when it's acting as coordinator). So what I would do is reduce the read load a lot to make sure I

libQtCassandra minus Qt

2012-01-05 Thread David Gosselin
Good afternoon, I am curious if anyone here has taken the libQtCassandra high-level client and stripped-out the Qt pieces to make it Qt independent? Thanks, David Gosselin Senior Software Engineer Acme Packet (781) 328-2604

Re: Writes slower then reads

2012-01-05 Thread R. Verlangen
The write and read load is very minimal the moment. Roughly 10 writes + 10 reads / second. So 20 operations per second. Don't think that overloads my cluster, does it? 2012/1/5 Philippe watche...@gmail.com You may be overloading the cluster though... My hypothesis is that your traffic is

Hector and CQL

2012-01-05 Thread dir dir
Hi Folk, I am a beginner user in Cassandra. I have a question about the usage and integration (or installation) hector into eclipse IDE? I try to find the answer by googling, but I do not find a proper guidance to do it. Would you want to help me by telling me how to do it or showing me the

Re: is it bad to have lots of column families?

2012-01-05 Thread Віталій Тимчишин
2012/1/5 Michael Cetrulo mail2sa...@gmail.com in a traditional database it's not a good a idea to have hundreds of tables but is it also bad to have hundreds of column families in cassandra? thank you. As far as I can see, this may raise memory requirements for you, since you need to have

Integration Error between Cassandra and Eclipse

2012-01-05 Thread bobby saputra
Hi There, I am a beginner user in Cassandra. I hear from many people said Cassandra is a powerful database software which is used by Facebook, Twitter, Digg, etc. So I feel interesting to study more about Cassandra. When I performed integration process between Cassandra with Eclipse IDE (in this

RE: java.lang.AssertionError

2012-01-05 Thread Michael Vaknine
Thanks Aaron. Michael From: aaron morton [mailto:aa...@thelastpickle.com] Sent: Wednesday, January 04, 2012 10:06 PM To: user@cassandra.apache.org Subject: Re: java.lang.AssertionError Will be fixed in 1.0.7 https://issues.apache.org/jira/browse/CASSANDRA-3656 Cheers

Re: Writes slower then reads

2012-01-05 Thread Philippe
Unless you are doing huge batches no... don't have any other idea for now... 2012/1/5 R. Verlangen ro...@us2.nl The write and read load is very minimal the moment. Roughly 10 writes + 10 reads / second. So 20 operations per second. Don't think that overloads my cluster, does it? 2012/1/5

Deciding on CF

2012-01-05 Thread Sunit Randhawa
Hello, We are working on some new cassandra requirements and I wanted to get your recommendations on how to go ahead and put schema in place in terms of how many CF one should have for below scenario: 1- There are 10 applications. Out of which 1 or 2 applications are very active giving 90%+

Re: Hector and CQL

2012-01-05 Thread rektide
Hector is a library. It needs to be added to your Eclipse project's build classpath somehow before you can begin using it in Eclipse. On Thu, Jan 05, 2012 at 11:25:16PM +0700, dir dir wrote: Hi Folk, I am a beginner user in Cassandra. I have a question about the usage and integration

Re: emptying my cluster

2012-01-05 Thread aaron morton
* In the design discussed it is perfectly reasonable for data not to be on the archive node. You mean when having the 2 DC setup I mentioned and using TTL? In case I have the 2 DC setup but don't use TTL I don't understand why data wouldn't be on the archive node? Originally you were

Re: Composite column docs

2012-01-05 Thread aaron morton
What client are you using ? For example pycassa has some sweet documentation http://pycassa.github.com/pycassa/assorted/composite_types.html Cheers - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 6/01/2012, at 12:48 AM, Shimi Kiviti wrote: Is

Re: Writes slower then reads

2012-01-05 Thread aaron morton
What happens when you turn off the cron jobs ? Cheers - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 6/01/2012, at 6:57 AM, Philippe wrote: Unless you are doing huge batches no... don't have any other idea for now... 2012/1/5 R. Verlangen

Re: Should I throttle deletes?

2012-01-05 Thread Maxim Potekhin
Hello Aaron, On 1/5/2012 4:25 AM, aaron morton wrote: I use a batch mutator in Pycassa to delete ~1M rows based on a longish list of keys I'm extracting from an auxiliary CF (with no problem of any sort). What is the size of the deletion batches ? 2000 mutations. Now, it appears that

Re: Hector and CQL

2012-01-05 Thread Brian O'Neill
If you are looking to add hector, you'll need: dependency groupIdme.prettyprint/groupId artifactIdhector/artifactId version1.0-2/version /dependency -brian Brian O'Neill Lead Architect, Software Development Health Market Science | 2700 Horizon Drive | King of Prussia, PA 19406 p:

Re: Should I throttle deletes?

2012-01-05 Thread Philippe
Then I do have a question, what do people generally use as the batch size? I used to do batches from 500 to 2000 like you do. After investigating issues such as the one you've encountered I've moved to batches of 20 for writes and 256 for reads. Everything is a lot smoother : no more timeouts.

Re: is it bad to have lots of column families?

2012-01-05 Thread Carlo Pires
Does index for CFs must fit in node's memory? 2012/1/5 Віталій Тимчишин tiv...@gmail.com 2012/1/5 Michael Cetrulo mail2sa...@gmail.com in a traditional database it's not a good a idea to have hundreds of tables but is it also bad to have hundreds of column families in cassandra? thank

Re: Should I throttle deletes?

2012-01-05 Thread Maxim Potekhin
Thanks, that's quite helpful. I'm wondering though if multiplying the number of clients will end up doing same thing. On 1/5/2012 3:29 PM, Philippe wrote: Then I do have a question, what do people generally use as the batch size? I used to do batches from 500 to 2000 like you do.

Re: Integration Error between Cassandra and Eclipse

2012-01-05 Thread Chris Gerken
I wouldn't worry about the warnings. Eclipse Java support defaults to fairly restrictive warning settings. You can go into the preferences for Java-Compiler and change the 'warning' settings to 'ignore' for any of those problems that you don't or shouldn't really care about. As for the

Re: Integration Error between Cassandra and Eclipse

2012-01-05 Thread Maki Watanabe
How about to use File-Import... rather than File-New Java Project? After extracting the source, ant build, and ant generate-eclipse-files: 1. File-Import... 2. Choose Existing Project into workspace... 3. Choose your source directory as root directory and then push Finish 2012/1/6 bobby saputra

Re: Integration Error between Cassandra and Eclipse

2012-01-05 Thread Maki Watanabe
Sorry, ignore my reply. I had same result with import. ( 1 error in unit test code many warnings ) 2012/1/6 Maki Watanabe watanabe.m...@gmail.com: How about to use File-Import... rather than File-New Java Project? After extracting the source, ant build, and ant generate-eclipse-files: 1.

Re: Integration Error between Cassandra and Eclipse

2012-01-05 Thread Yuki Morishita
Also note that Cassandra project switched to git from svn. See Source control section of http://cassandra.apache.org/download/ . Regards, Yuki -- Yuki Morishita On Thursday, January 5, 2012 at 7:59 PM, Maki Watanabe wrote: Sorry, ignore my reply. I had same result with import. ( 1 error

RE: Integration Error between Cassandra and Eclipse

2012-01-05 Thread Kuldeep Sengar
Hi, Can you post the error(saying that only 1 error is there), that'll make things more clear. Thanks Kuldeep Singh Sengar Opera Solutions Tech Boulevard,8th floor, Tower C, Sector 127, Plot No 6,Noida 201 301 +91 (120) 4642424 facsimile, Ext : 2418 +91 8800595878 (M) -Original

Re: Integration Error between Cassandra and Eclipse

2012-01-05 Thread Dave Brosius
This works for me http://wiki.apache.org/cassandra/HowToDebug On 01/06/2012 01:18 AM, Kuldeep Sengar wrote: Hi, Can you post the error(saying that only 1 error is there), that'll make things more clear. Thanks Kuldeep Singh Sengar Opera Solutions Tech Boulevard,8th floor, Tower C, Sector

Re: Dealing with Corrupt (negative) value length encountered

2012-01-05 Thread Philippe
Thanks Aaron, I was able to complete the repair by scrubbing the column family on all three replicas. Cheers 2012/1/4 aaron morton aa...@thelastpickle.com I was able to scrub the node the repair that failed was running on. Are you saying the error could be displayed on that node but the bad