# Firecracker-demo

## Disclaimer

This demo showcases Firecracker's agility and high-density capabiliies.
**It's been run on an EC2 i3.metal host (the defaults start 4000 microVMs)
with an Ubuntu and an Amazon Linux 2 host OS, from an Ubuntu client.**

Deviations from this setup will probably lead to issues and/or sub-par performance.
If you want to help us support the demo on more platforms...we take
pull requests :)

## Step-by-Step Instructions

Get this repo on an EC2 Intel metal instance.
Open two terminals/ssh-connections to the instance.

### Terminal window 1

will show a heatmap of network traffic done by each microVM.

```bash
python3 microvm-tiles.py
```

### Terminal window 2

will control the rest of the demo.

Raise the maximum processes limit.

```bash
sudo tee -a /etc/security/limits.conf <<EOL
$USER soft nproc 16384
$USER hard nproc 16384
EOL
```

Note: In the above configuration, `$USER` expands
to the ec2 instance logged-in user.

Reload the ssh session to have the new limit applied.

Install additional dependencies: `python3` and `iperf3`.

Fix permissions on `/dev/kvm`:

```bash
sudo chmod 777 /dev/kvm
```

Create 4000 TAPs, configure networking for them and start 4k `iperf3` servers
each bound to their respective TAP.

```bash
sudo ./0.initial-setup.sh 4000
```

#### Start 4000 Firecracker microVMs

Use 6 parallel threads to configure and start **4000** microVMs. Each
thread will get an equal slice of the 4k total and sequentially configure
and issue the start command for each microVM.

The script will report **total duration** as well as **mutation rate**.

```bash
# start a total of 4k uVMs from 6 parallel threads
./parallel-start-many.sh 0 4000 6
# ... wait for it ... should take around 60 seconds ... watch the heatmap
```

Each microVM has a workload (iperf client) and will run it in a loop with
a random `sleep` between iterations.

Looking at the heatmap you should see **six** 'snakes' advancing which
are the microVMs that have just been powered up and are doing their first
iteration of the workload. Once that's done, the random sleep will lead
to random lighting of the heatmap.

#### Pick a microVM and play with it

Pick a number `0 <= ID < 4000`. For this example `42` was chosen.

```bash
ID="42"
# get the IP for that microVM
ip addr show fc-$ID-tap0 | grep "inet "
       inet 169.254.0.170  netmask 255.255.255.252  broadcast 0.0.0.0

# IP of microVM on other side is *one less*
ssh -i resources/rootfs.id_rsa root@169.254.0.169
```

You're now inside the microVM. Do as you please.

Let's make it stand out in the heatmap.

```bash
# stop the workload service
localhost:~# rc-service demo-workload stop
 * Stopping demo-workload ...                                    [ ok ]
# manually run iperf with a higher bandwidth than the rest
localhost:~# iperf3 -c $(./gateway-ip.sh) -b 104857600
# check out the heatmap
```

This microVM should now shine brighter in the heatmap.

Demonstrate the network throughput of this microVM:

```bash
localhost:~# iperf3 -c $(./gateway-ip.sh)
Connecting to host 169.254.0.170, port 5201
[  5] local 169.254.0.169 port 53392 connected to 169.254.0.170 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  1.72 GBytes  14.8 Gbits/sec    0    952 KBytes
[  5]   1.00-2.00   sec  1.67 GBytes  14.4 Gbits/sec    0    952 KBytes
[  5]   2.00-3.00   sec  1.76 GBytes  15.1 Gbits/sec    0    952 KBytes
[  5]   3.00-4.00   sec  1.69 GBytes  14.5 Gbits/sec    0    952 KBytes
[  5]   4.00-5.00   sec  1.69 GBytes  14.5 Gbits/sec    0    952 KBytes
[  5]   5.00-6.00   sec  1.66 GBytes  14.3 Gbits/sec    0    952 KBytes
[  5]   6.00-7.00   sec  1.67 GBytes  14.4 Gbits/sec    0    952 KBytes
[  5]   7.00-8.00   sec  1.77 GBytes  15.2 Gbits/sec    0    952 KBytes
[  5]   8.00-9.00   sec  1.76 GBytes  15.1 Gbits/sec    0    952 KBytes
[  5]   9.00-10.00  sec  1.42 GBytes  12.2 Gbits/sec    0    952 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  16.8 GBytes  14.4 Gbits/sec    0             sender
[  5]   0.00-10.00  sec  16.8 GBytes  14.4 Gbits/sec                  receiver

iperf Done.
```

#### Plot the 4000 Firecracker microVMs boot times

To plot the boot times, on your local machine or any non-headless setup:

```bash
scp -i <identity-key> ec2-user@<i3.metal-ip>:firecracker-demo/{data.log,gnuplot.script} .
gnuplot gnuplot.script
xdg-open boot-time.png  # on Ubuntu. For other distros just use your default .png viewer.
```