Zookeeper Setup

Procedure

Create a file /var/zookeeper/myid on each cluster node with unique value (for example 1,2,3) on each node.
```
mkdir -p /var/zookeeper
echo "1" > /var/zookeeper/myid
```

Edit zookeeper.properties file under <KAFKA_HOME>/config directory.

dataDir=/var/zookeeper
clientPort=2181
maxClientCnxns=0
tickTime=2000
initLimit=5
syncLimit=10
dataLogDir=/var/log/zookeeper
server.1=<KAFKA_CLUSTER_HOST1_IPADDRESS>:3181:4181
server.2=<KAFKA_CLUSTER_HOST2_IPADDRESS>:3181:4181
server.3=<KAFKA_CLUSTER_HOST3_IPADDRESS>:3181:4181
authProvider.1=org.apache.zookeeper.server.auth.SASLAuthenticationProvider
authProvider.2=org.apache.zookeeper.server.auth.SASLAuthenticationProvider
authProvider.3=org.apache.zookeeper.server.auth.SASLAuthenticationProvider
requireClientAuthScheme=sasl

Note: 2181 is the port on which Zookeeper will listen for connections. Instead of 3181 and 4181, any port number can be used, but ensure same ports are used across all 3 nodes.

Create a new zookeeper_jaas.conf file under <KAFKA_HOME>/config directory with below content:
```
Server {
org.apache.zookeeper.server.auth.DigestLoginModule required
user_super="zookeeper"
user_kafka="zoo-pwd";
};
```
Note: The file zookeeper_jaas.conf is used for authentication.

Note: user_super: superuser will have automatically administrator privileges.

Note: user_kafka: kafka is the username and password is zoo-pwd. The user kafka and password can be anything.
Start Zookeeper server by running below command:
KAFKA_OPTS="-Djava.security.auth.login.config <KAFKA_HOME>/config/zookeeper_jaas.conf" <KAFKA_HOME>/bin/zookeeper-server-start.sh -daemon <KAFKA_HOME>/config/zookeeper.properties

Check the status of Zookeeper service by running any the below command:

a. ps -aef | grep zookeeper or ps -aef | grep zookeeper.properties 
b. lsof -i:2181 
c. netstat -tnlup | grep 2181