Apache Cassandra is an open source distributed database management system.

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cassandra on centos 7 - service control issues

I'm trying to join a set of new CentOS 7 servers to an existing cassandra cluster. All systems are running the same version (2.1.2). Running into these problems and would appreciate some pointers: ...
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1answer
31 views

Incredibly high load average on a Centos server

I have a Centos 6.4 server that's being used as a Cassandra node in a production environment, it is still working and responding to queries etc, but the load average is rather "high" a.k.a. buggy? In ...
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3 views

cassandra dynamic columns with integer values as column names and list values

I want to create a search index in Cassandra. The user_id is the primary key, next the keyword column(part of primary key) comes, then dynamic columns should follow where the column name is some ...
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1answer
14 views

4 node cassandra - skip redundancy?

After much pleading and case building my group got the budget to buy 4 nodes and start a cassandra cluster. Each machine has 3x1Tb drives so I'm wondering whether it's reasonable to skip the 1 way ...
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10 views

opscenter agent -f works

I feel certain this is something fairly basic that I'm missing, I'm new to Cassandra and very new to Opscenter and the agent. In brief, Opscenter is working fine and the agent install seems to have ...
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0answers
22 views

Tunneling cassandra via ssh gives me a connection closed error

I have a server with two network interfaces. Cassandra is listening on a dedicated internal database network on eth1 (not accessable from outside). So I do my tunnel like this: ssh -f -N ...
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47 views

Repairing OpsCenter rollups60 Results in Snapshot Errors

I am running a 6 node cluster using Apache Cassandra 2.1.2 with DataStax OpsCenter 5.0.2 from the AWS EC2 AMI "DataStax Auto-Clustering AMI 2.5.1-hvm" (DataStax Community AMI). When I try to run a ...
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31 views

OpsCenter : Error loading column family: Make sure all agents are running and connected properly

I'm using OpsCenter version: 5.0.2 and Cassandra 2.1.2 on localhost. I can access keyspaces and see columns list, but when trying to display content of any column I'm getting message: Error ...
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1answer
21 views

datastax opscenter - how is 'storage capacity' determined?

I installed the OS version this recently (5.0.2) and am wondering about this graph. To date I've had a hard time finding a metric for 'cluster capacity' when it comes to Cassandra. Magically, datastax ...
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1answer
78 views

Cassandra: do more storage size, needs more CPU and RAM

I have gone through the recommended architecture of the Cassandra node configuration! according to which the recommended hardware infrastructure for the node is to have RAM: 16-32 GB, storage: 500GB ...
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146 views

Opscenter is connected to datastax agents but no data available

We installed opscenter and datastax agents on a cluster with private network through datastax community packages. Configurations seems to be ok and we don't have connectivity issues on jmx or stomp. ...
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1answer
33 views

How to avoid constant schema disagreement flapping in Cassandra?

We have a 3 node Cassandra cluster with a small amount of data on 'em (about 2.3GB total). The nodes are hosted on GCE and each have four cores and 16GB memory. We're running the Debian package build ...
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1answer
277 views

How to resolve a stuck major compaction in Apache Cassandra?

I've got a one-node Cassandra cluster which is currently stuck in a major compaction process. After executing a nodetool compactit started the compaction and I see the tmp-sstable files with a size of ...
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1answer
32 views

Change hostname in datastax-agent

I've noticed when working in Opscenter that all the nodes are displayed with the result of hostname and their IP address. For an ec2 host this is a little redundant since the hostnames look like ...
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1answer
13 views

cassandra setup - uneven load - what did I do wrong?

For the sake of understanding I setup a 4 node cluster using the latest/greatest(released) version of Cassandra. The four nodes were brought up in sequence using almost entirely default settings and ...
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1answer
91 views

cassandra nodetool repair - how to schedule properly?

Im putting together a 16 node cassandra cluster (replication factor 2) and want to setup a schedule for nodetool repair. gc_grace_seconds is at the default. Two questions: My first impulse is to ...
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2answers
57 views

Cassandra: understanding replication factor

Hypothetical situation: Setup a cassandra cluster with N nodes. Create a keyspace and set replication_factor to 1 and use SimpleStrategy. Add some data. Remove 1 node. Does this mean that 1/N of ...
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1answer
48 views

Which direction does `nodetool repair` go?

Let's say I log into a Cassandra node X and issue nodetool repair. Will I only repair the data residing on X? Or will I also automatically repair all other nodes that have replicas of what X holds ...
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1answer
59 views

Agent connected to Opscenter but no data available

I'm currently running Cassandra, the OpsCenter, and the OpsCenter agent all on my dev Windows box. The agent is successfully connected to OpsCenter and I can see it listed there along with the amount ...
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1answer
72 views

Can't get datastax-agent to run on a new node

I'm trying to install the datastax-agent on a new CentOS node (there are 3 other nodes currently up and running correctly). After installing the datastax-agent via the Opscenter UI it appears to ...
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0answers
17 views

Cassandra: when to add capacity?

How does one know when it's time to add capacity to a cassandra cluster? Error msgs? Performance? Some other tell-tale sign? Since capacity planning with Cassandra is a (seemingly) black art knowing ...
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0answers
51 views

When adding data to cassandra cluster from C#, I get an this exception

From C# when I try to add data to a cassandra cluster, I get this exception: {Not enough replicas available for query at consistency One (1 required but only 0 alive)"} When I run nodetool from ...
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1answer
42 views

Multiple data centers and DataStax OpsCenter

Multiple questions regarding DataStax OpsCenter. I am evaluating for our use OpsCenter 5.0.1 I am able to build a cassandra cluster using opscenter sucessfully. However, all nodes belong to one ...
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1answer
48 views

Datastax Opscenter 5.0: Getting “InvalidGroup.NotFound” when adding node via AWS

I am getting an "InvalidGroup.NotFound" when trying to add an additional node to my cluster through OpsCenter via AWS. The existing node running OpsCenter is in the VPC and is already using the ...
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1answer
94 views

Operator \> and \< (string version comparison) are not recognised in shell script

I am trying to run Casandra nodetool and getting warnings coming from .sh script. [root@d11ca4cc-fa95-c8a9-e133-e64c434f0e6f ~]# nodetool status /opt/local/share/cassandra/bin/nodetool[53]: .[97]: ...
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2answers
148 views

azure endpoint for cassandra does not work for ports 7000, 7001, 7199

I have setup apache cassandra on a centos7 compatible linux machine in azure. I can telnet directly to port 7000, etc on the IP address on the machine, however I cannot telnet to that same port from ...
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28 views

Cassandra 2.x - Problems with not accessible data

I had 3 nodes with 1.5TB of data. At some point my import hit a wall as disk space ended on one of those 3 nodes. I've resized disks and added 4 more nodes and 1.5TB of data more. I did also repair ...
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75 views

How to authenticate with cassandra-stress 2.1

Is there a way to authenticate to cassandra using the new cassandra-stress tool released with cassandra 2.1? It appears as if the '-un' (username) and '-pw' (password) switches have been removed from ...
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1answer
439 views

Cassandra 2.x - cluster does not rebalance after adding new nodes

I had 3 nodes, all with ~550GB, and added 4 more. I hoped that data would migrate on its own from old servers to new ones. Unfortunately after one day, data seems to stay in old places. In parallel, ...
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55 views

VPN load balancing between AWS regions for DataStax cluster

I am testing some DataStax Enterprise clusters in different AWS regions and working on a desirable architecture. Currently - I have one cluster with datacenters in us-east, us-west, and eu-ireland. I ...
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1answer
91 views

DataStax OpsCenter 5.0.0 API doesn't increase last_seen when nodes down if DataStax OpsCenter Agent is down, used to work with 3.2.2

I've been using the DataStax OpsCenter (Enterprise) 5.0.0 REST API with DSE 4.5.1 (Cassandra 2.0.9) to query the /$cluster_name/nodes endpoint and see the last_seen field for the number of seconds ...
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106 views

Does nodetool repair repair the next node?

Let's assume we have a Cassandra cluster with the following ring: A -> B -> C -> D (no virtual nodes), and we assume that all the data is stored at RF=2. Now let's say that B dies, leaving us ...
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1answer
113 views

OpsCenter on AWS: No permission to create /mnt/cassandra/data directory [closed]

Followed the instructions here: http://www.datastax.com/documentation/cassandra/2.0/cassandra/install/installAMILaunch.html Installed OpsCenter on m3.large. When launching an instance, I get this ...
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66 views

Broken apt trying to install Cassandra

While trying to install Cassandra on Ubuntu 13.10, the installation crashed and now I'm stuck with broken (?) apt-get. Here is the output of an apt-get install -f: Reading package lists... Done ...
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1answer
31 views

How to copy perf graphs from one user to another in datastax OpsCenter?

I have lots of perf graphs in datastax OpsCenter under my "admin" user. I've created a new read-only user that i can let anyone in the company use, but how do i copy all the already configured perf ...
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1answer
202 views

DataStax OpsCenter - can't connect with agents

I've installed DataStax OpsCenter (Apache Cassandra) and in OpsCenter, there is an error: "0 of 1 agents connected". When I click "fix", enter credentials and try to install nodes, i get error: ...
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127 views

Creating Table in mariaDB - ERROR 1429 (HY000)

I successfully integrated mariaDB-10.0.13 with Cassandra-2.0.8 and 2.0.9 I was able to created a table present in cassandra on mariaDB and was able to query successfully. But my problem is that ...
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1answer
292 views

Opscenter is unable to install agents due permission denied to /tmp

O am not able to install agents on 10.0.0.29 IP through opscenter. It says below error. The user is pavan and this user is having sudo access. Opscenter is unable to install the agents and I'm not ...
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1answer
660 views

Setting-up OpsCenter gives: scp /tmp/.. Permission denied

I'm trying to setup OpsCenter by adding my localhost Cassandra node (for testing). The login credentials I used for SSH has sudo/root rights, nevertheless I get the error: scp: /tmp/tmpXInRfq: ...
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170 views

Adding Cassandra Node in OpenShift to Existing Cluster

I have 3 cassandra nodes(S1,S2,S3) which are installed on CentOS 6. Two of them (S1,S2) are in datacenter A and one of them (S3) is in openshift. I am trying to make benchmark test with multiple node ...
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1answer
311 views

OpsCenter 5.0: No Data on Dashboard Graphs

I have an OpsCenter 5.0 instance running and 10 agents connected. The agents are in 2 regions in AWS, so everything is using external addresses to communication. All the necessary ports are open, ...
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1answer
56 views

Opscenter 5.0: User management query

I've installed the free tarball version of opscenter and am having problems with the user management aspect of it. I have authentication enabled via: [authentication] enabled = true ...and can ...
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1answer
398 views

Opscenter 5.0: error when adding cluster, cluster added anyway, no clusters shown

I have a new Opscenter installation. After adding my "existing cluster" to opscenter, I get the following error dialog boxes: Error creating cluster: Cannot read property 'datasource' of undefined ...
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40 views

Cassandra - moving data from multiple nodes to a single node

I need to copy data from 3 nodes to a single node. I know about snapshot command and I was able to successfully copy data from a cluster where each node had 100% data (full replication) to a ...
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1answer
72 views

Opscenter 4.1.4: Authentication failing

I'm getting authentication errors when starting the opscenter agents on each of my cassandra (v1.2.5) nodes: INFO [main] 2014-07-23 12:18:03,880 Starting Stomp INFO [main] 2014-07-23 12:18:03,881 SSL ...
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37 views

Accidentally added node to wrong datacentre in Cassandra

I accidentally set a node to DC1 when it should have been DC2 . In cassandra-rackdc.properties I started the node and in opscentre it added it to DC1. I then stopped the node and changed the config ...
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2answers
103 views

EC2 Attach Instance Store on Start

I'm lunching an instance to host a Cassandra node and i'm testing some shutdown and startup scripts. The instance was lunched from the datastax PV AMI 'ami-8932ccfe'. I added 8GB of SSD EBS storage ...
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41 views

Replace existing DataStax OpsCenter Installation in EC2

I'm using DataStax OpsCenter v3.2 installed on an EC2 instance. AWS is going to retire the instance, so I set up a new instance, installed OpsCenter, and tried to connect to my cluster. I got the ...
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1answer
249 views

Opscenter repair service times out. ERROR: Requested range intersects a local range […]

My production cluster had the repair service enabled since april 16th with the default 9 days time to completion and repairs would complete properly. However, since may 22nd, it is being disabled ...
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84 views

Cassandra hangs with kernel exception when adding jna jar to classpath

I have a fresh installation of cassandra v2.0.8 on a RedHat Enterprise Linux v5. I have added a sym link of the jna.jar in cassandra's /lib folder. I start cassandra and it hangs after printing out ...