What I See

Using curl to send JSON data to an API. Below is a very simple command to send JSON data to your API. curl -H "Content-Type: application/json" -d '{"firstname":"ahmed","lastname":"zzzz"}' http://localhost:3000/login Above command will send a JSON as below to link http://localhost:3000/login { "firstname":"ahmed", "lastname":"zzzz" } ​

Increasing Zookeeper Heap Size. In Location $ZOOKEEEPER_HOME/conf/java.env create a file if it does not exist. Add the following entry to set zookeeper max heapsize to 2048 MB. Then restart the zookeeper service. export JVMFLAGS="-Xmx2048m" Similarly we can set -Xms and Other Java Options as required. ​

Installing  OpsCenter  Monitoring for Cassandra. Setting up a  opscenter  for our  cassandra cluster. Download  opscenter  Archive. wget http://downloads.datastax.com/community/opscenter-5.0.tar.gz Extracting  opscenter . Extracting, Create and Change owner. sudo tar xvzf opscenter-5.0.2.tar.gz -C /opt/ cd /opt/ sudo ln -s opscenter-5.0.2 opscenter sudo chown cassandra:cassandra -R opscenter* Configure  opscenter Update configuration file. vim /opt/opscenter/conf/opscenterd.conf Update the interface as below. [webserver] port = 8888 interface = 10.10.18.35 Configuring Agent. Update the File below vim /opt/opscenter/agent/conf/address.yaml Add Below Line. stomp_interface: "10.10.18.35" Starting opsCenter. /opt/opscenter/bin/opscenter Open the browser with below URL. http://10.10.18.35:8888/opscenter/index.html In the UI Select, Manager Existing Cluster. (Manage an existing DataStax Enterprise or Cassandra cluster with OpsCenter.)

Creating a Multi-node Cassandra Cluster on Centos 6.5. Table of Contents Initial Server Setup Hardware Information Setting Host for  cassandra Updating  hostname  on all servers. Creating  cassandra  user with  sudo  permissions. Creating passwordless entry from SEED ( CASSANDRA01 ) to other servers. Extracting Files. Updating Configuration File. Setting  initial_token  as below. On Node  CASSANDRA01 On Node  CASSANDRA02 On Node  CASSANDRA03 Starting  cassandra . Checking Cluster Information. Logging into CQL Shell. Data Location on CASSANDRA01, CASSANDRA02, CASSANDRA03 Performace Tuning. Updating  cassandra.yaml  file. Updating  cassandra-env.sh  file. Updating  cassandra-topology.properties  file. Useful Links This is a basic multi-node cassandra setup. Initial Server Setup Hardware Information All the server were with below configuration. CPU : 40 Cores RAM : 192GB Setting Host for  cassandra Setting up the servers and update