[Update Documentation] Getting started with OpenSearch-Benchmark!

[AkshathRaghav]

Context:
There are different ways to get started with running a cluster and running a benchmark against it.
I was trying to use the docker-compose.yml from opensearch.org, but was facing SSL issues, so I thought I'd make this "guide" so everyone can get started with it quickly!
Below, I'm going to outline the simplest set of instructions I've found for getting started with OSB for the first time. Huge thanks to @IanHoang and @rishabh6788 for helping everyone in Slack.

Steps:
This can be reproduced on both Linux and Windows (WSL).

1. Download the tar.gz from https://opensearch.org/downloads.html. If you are using WSL, I'd recommend downloading this using wget into your /home/ directory instead of /mnt/c.

wget https://artifacts.opensearch.org/releases/bundle/opensearch/2.10.0/opensearch-2.10.0-linux-x64.tar.gz

2. Extract the folder

tar -xf opensearch-2.10.0-linux-x64.tar.gz
cd opensearch-2.10.0

3. Add following settings to the opensearch.yml file under the config directory

vim config/opensearch.yml

discovery.type: single-node 
plugins.security.disabled: true 

4. Run the opensearch-tar-install.sh script.

bash opensearch-tar-install.sh

5. Check the output of curl.exe "http://localhost:9200/_cluster/health?pretty". Output should be similar to this:

{
  "cluster_name" : "<name>",
  "status" : "green",
  "timed_out" : false,
  "number_of_nodes" : 1,
  "number_of_data_nodes" : 1,
  "discovered_master" : true,
  "discovered_cluster_manager" : true,
  "active_primary_shards" : 3,
  "active_shards" : 3,
  "relocating_shards" : 0,
  "initializing_shards" : 0,
  "unassigned_shards" : 0,
  "delayed_unassigned_shards" : 0,
  "number_of_pending_tasks" : 0,
  "number_of_in_flight_fetch" : 0,
  "task_max_waiting_in_queue_millis" : 0,
  "active_shards_percent_as_number" : 100.0
}

6. Before we move on, make sure to have gone through the and activated your virtual environment. TIP: Just to avoid Pyenv breaking, run the following command before you reach

sudo apt-get install -y make build-essential libssl-dev zlib1g-dev libbz2-dev \
libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev \
xz-utils tk-dev libffi-dev liblzma-dev git

7. For the last step, we'd be executing the geonames benchmark which can be found from the repo.

opensearch-benchmark execute-test --pipeline=benchmark-only --workload=geonames --target-host=127.0.0.1:9200 --test-mode --workload-params '{"number_of_shards":"1","number_of_replicas":"0"}'

And we should be done! You should be seeing the performance metrics!
If you are not seeing any results immediately, it should be an indicator that there is an issue with your cluster. Use the command below to view the cluster logs

tail -f ~/.bencmark/logs/bechmark.log