Apache Cassandra is an open source distributed database management system.

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How to choose NoSQL database engine?

We have a database with following specs: 30k records, 7mb in size 20 inserts/second 1000 updates/second 1000 range selects/second, by secondary index, approx 10 rows each needs at least one ...
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2answers
350 views

Dynamically changing one-node Cassandra cluster to two nodes

So I have an application that will be very dormant most of the time but will need high-bursting a few days out of the month. Since we are deploying on EC2 I would like to keep only one Cassandra ...
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2answers
78 views

startup cassandra layout

We've got a relatively low-traffic site (~1K pageviews/day) hosted on a single server, and expect it to grow significantly over the next few years. I'm thinking of moving over to Rackspace ...
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1answer
1k views

Unclosed TCP connections in CLOSE_WAIT for various processes

I have cluster of several machines connected on 10GBE network (NICs are Intel 82599EB 10GBE SFI/SFP+) running under Debian 6.0 and faced with problem of hung up TCP connections in CLOSE_WAIT state. I ...
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2answers
518 views

Configuring Cassandra for consistency across multiple datacenters

Currently we run a 4-node Cassandra ring in each of two datacenters. We would like to rebuild them into a single 8-node ring. All else being equal we would really like to have consistent reads, so we ...
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1answer
247 views

How to find date/time used by Cassandra

Earlier this morning I noticed that one of the nodes in our Cassandra cluster is writing logs an hour in the future, despite the date/time being correct on the OS. A couple of other nodes I checked ...
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1answer
575 views

Reconfiguring data directories in an existing Cassandra node

I'm currently running a very simple single-node Cassandra box with the data files on a single disk. I'm about to add a couple of SSDs to the box and intend to add each SSD as another data directory to ...
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2answers
255 views

How to build snappy-java under FreeBSD 8.1? (build error)

I'm trying to build snappy-java for FreeBSD 8.1 to use it with cassandra (can't enable columns compression without it). Trying to build it from source and getting an error: $ hg clone ...
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1answer
132 views

How do I automatically add Cassandra nodes to Windows DNS?

I'm working on building a new Cassandra cluster and I'd like to create a DNS record that will hold the IP addresses of all of the nodes. I build all of my servers in the cloud and they automatically ...
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2answers
496 views

How to find causes for the casandra killing frequently?

Installed the cassandra 0.8 in centos linux system with 1GB ram. Within an hour after starting the cassandra, it is dying frequently. Also, i can say java is also killing , which is necessary for ...
2
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1answer
723 views

Many concurrent Cassandra database connections thru SSH tunnel

I have an application that uses the PyCassa Cassandra client to open many concurrent connections to a Cassandra server. When I run the client application locally on the database server, it works. ...
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0answers
221 views

Cassandra, very long row (over 800.000 columns), row cache and manual repair

I seemed to have hit quite interesting problem recently while investigating my previous problem -- One ColumnFamily places data on only 3 out of 4 nodes We had a very long row with over 800.000 ...
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1answer
834 views

Unable to compile thrift on ubuntu

I am trying to install cassandra and thrift in my PC. I have successfully installed cassandra. But while making (using "make" command) thrift I am getting the error below: ............... ...
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2answers
106 views

One ColumnFamily places data on only 3 out of 4 nodes

I have posted this on cassandra-user mailing list however didn't get any responses just yet and I was wondering whether someone here on serverfault.com will have any ideas. I seem to have came across ...
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2answers
270 views

Cassandra-cli could not connect to localhost

I have installed cassandra 1.0.1 stable binary in ubuntu server 11.10 amd64. But, when i try to connect using cassandra-cli with: [default@unknown] connect localhost/9160 The system always ...
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2answers
842 views

cassandra node discovery

I just set up a 3 node system with ip addresses "192.168.0.101", "192.168.0.102", "192.168.0.103". I have set the seeds value on the configuration of all three machines as seeds: ...
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1answer
481 views

Processing pre-existing log files with Flume

I have a large set of log files that I need to extract data from. Is it possible to use Flume to read these files and dump them into an HDFS (Cassandra, or another data source) which I can then ...
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2answers
793 views

Cassandra: capacity planning [duplicate]

Im investigating moving some large DBs from MySQL to Cassandra and Im trying to figure out how to plan the cluster. Historically, one would just buy disks to contain the relevant data but Im not clear ...
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3answers
2k views

Can't upgrade my Ubuntu server, it gets stuck on openjdk-6-jre-headless

I am using Ubuntu Server. When I do: apt-get upgrade it gets stuck on: Setting up openjdk-6-jre-headless (6b20-1.9.7-0ubuntu1) ... Why? And what can I do to stop it? I tried removing it with ...
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1answer
3k views

Cannot connect to my Cassandra

My Cassandra used to work with no problems. I was able to connect with no problems but now for some reason it doesn't work anymore. [default@unknown] connect localhost/9160; Exception connecting to ...
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1answer
264 views

introduce latency between ec2 instances

I have a 2nodes Cassandra ring on ec2 (10.96.31.143, 10.254.94.177) in the same zone (east-1). How can I introduce a 3 seconds delay for all cassandra-related network communications between them? I ...
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1answer
250 views

Installing Thrift with Solandra

I am trying to install Thrift with Solandra. Normally when I just want to install Thrift with Cassandra, I followed this tutorial: https://wiki.fourkitchens.com/display/PF/Using+Cassandra+with+PHP ...
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1answer
2k views

What is the best solution for backing up data in Cassandra? [closed]

What is the best solution for backing up data in Cassandra?
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1answer
268 views

IP address resolution in Cassandra MultiDC setup

We have a scenario for which we are considering using apache Cassandra for deployment for our data storage needs.The setup is to be spread across multiple data centers in different regions(physical ...
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1answer
384 views

Unable to connect to cassandra when using the AllowAllAuthenticator

I installed cassandra on a VM running Ubuntu Server 10.10. cassandra login failure with org.apache.cassandra.auth.AllowAllAuthenticator but I always receive the following error message: Login ...
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2answers
4k views

CentOS open port 7000 [RESOLVED]

I have two boxes one ubuntu v10.10 (IP: 192.168.12.128) and another centos v5.5 (IP: 192.168.12.131) I m able to ping centos from ubuntu box and vice versa. When I telnet UBUNTUIP using port 7000 ...
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6answers
715 views

How to achieve zero down time

For an application we want to achieve zero database and application down time using Active Active configuration. Our dB is Oracle Following are my questions: How can we achieve active active ...
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1answer
780 views

Cassandra on Linode: Dark magic isn't working

Yes, I realize I'm crossing the streams by running Cassandra on Linode. Yes, I know it would be better to run it on Rackspace or Amazon, but that's immaterial right now. Basically, I've got a Private ...
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1answer
280 views

Ubuntu: Freeing up ports?

I have tried to install cassandra on my Ubuntu test environment, but what happens when I try to start it is that I get the following error: java.net.BindException: Address already in use I have ...
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0answers
681 views

Cannot to connect to a Cassandra DB from localhost

I don't know if I'm on the right site, I installed OpenSolaris a single cassandra node, I don't have other node. On the same server, I install Ruby 1.8 with the gem Cassandra. If I try to connect ...
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2answers
3k views

How can I get Cassandra to automatically rebalance?

I am looking at a cassandra cluster, but the administration effort seems to be quite high. Is there any way I can configure Cassandra to rebalance nodes automically as new machines are added, some are ...
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1answer
368 views

Does anyone have any advice on administering a large Cassandra cluster? [closed]

Does anyone have any advice on administering a large Cassandra cluster (> 50 nodes)? I am looking at both Riak and Cassandra and need to know the performance and operational characteristics and ...
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1answer
622 views

Cassandra nodes in multiple data centers

http://www.cs.cornell.edu/projects/ladis2009/papers/lakshman-ladis2009.pdf : "Cassandra is configured such that each row is replicated across multiple data centers." So in that case is it good to ...