keytool -list -v -keystore keystore.ts -storepass PASSWORD

In the main server block (e.g. /etc/nginx/nginx.conf) add the following:

        if ($http_user_agent ~* (AgentName) ) {
        return 403;
        }

Test nginx config and restart:

nginx -t
service nginx restart

To test the agent gets blocked:

curl -I -H 'User-agent: AgentName' localhost/bla

HTTP/1.1 403 Forbidden

It is worth checking the replication factor before modifying:

./path/to/kafka/bin/kafka-topics.sh --describe --zookeeper localhost:2181 --topic test-topic

Topic:test-topic        PartitionCount:2        ReplicationFactor:1     Configs:
        Topic: demo-topic       Partition: 0    Leader: 0       Replicas: 0     Isr: 0
        Topic: demo-topic       Partition: 1    Leader: 1       Replicas: 1     Isr: 1

It can be seen here that the replication factor is 1.

To update to a replication factor of e.g. 3 firstly create a json file with a new reassignment plan. Call it e.g. reassignment-plan.json:

List all registered VM ID’s:

vim-cmd vmsvc/getallvms

Power off vm:

vim-cmd vmsvc/power.off VMID

Check vm power status:

vim-cmd vmsvc/power.getstate VMID

vim-cmd vmsvc/getallvms