How to send email using SMTP and telnet prompt

telnet 25
ehlo sender.com
mail from: sgokhale@sender.com
rcpt to: sgokhale@receiver.com
data
subject: test mail from sender app
test email body
.

How to monitor ElasticSearch instance

$ curl http://:9200/_cat/indices
$ curl http://:9200/_cat/aliases
$ curl http://:9200/_cluster/_status

How to monitor Redis server

On a REDIS server

redis-cli -p 6379 -h info server

redis-cli -p 6379 -h set shashi gokhale

redis-cli -p 6379 -h get shashi