feat: latency simulation

benchmark/playbooks/tc_apply.yml

@@ -0,0 +1,26 @@
+- name: Apply all TC rules
+  hosts: all
+  become: true
+
+  vars:
+    ansible_ssh_user: root
+
+  tasks:
+    - name: Upload latencies csv file
+      copy:
+        src: "{{ playbook_dir }}/../config/latencies.csv"
+        dest: /home/bob/latencies.csv
+
+    - name: Upload machines IPs list
+      copy:
+        src: "{{ playbook_dir }}/../machines.txt"
+        dest: /home/bob/machines.txt
+
+    - name: Upload tc script
+      copy:
+        src: "{{ playbook_dir }}/../scripts/apply-tc-rules.py"
+        dest: /home/bob/apply-tc-rules.py
+        mode: 0744
+
+    - name: Apply tc rules
+      command: "/home/bob/apply-tc-rules.py /home/bob/latencies.csv /home/bob/machines.txt {{ ansible_host }}"

benchmark/playbooks/tc_reset.yml

@@ -0,0 +1,10 @@
+- name: Reset all TC rules
+  hosts: all
+
+  vars:
+    ansible_ssh_user: root
+
+  tasks:
+    - name: Reset all TC rules
+      shell: tc qdisc del dev eth0 root
+      ignore_errors: yes

benchmark/scripts/apply-tc-rules.py

@@ -0,0 +1,76 @@
+#!/usr/bin/python3
+# INTENDED TO BE EXECUTED ON BENCHMARK MACHINES
+import sys
+import csv
+import subprocess
+
+def read_matrix(csv_file):
+    with open(csv_file) as f:
+        reader = csv.reader(f)
+        header = next(reader)[1:]
+        matrix = {}
+        for row in reader:
+            row_zone = row[0]
+            matrix[row_zone] = {}
+            for i, col_zone in enumerate(header):
+                matrix[row_zone][col_zone] = int(row[i+1])
+    return header, matrix
+
+def read_ips(ip_file):
+    with open(ip_file) as f:
+        return [line.strip() for line in f if line.strip()]
+
+def execute_command(cmd):
+    subprocess.run(cmd, shell=True, check=True)
+
+def build_tc_commands(header, matrix, ips, local_ip):
+    commands = []
+    num_zones = len(header)
+    local_index = ips.index(local_ip)
+    local_zone = header[local_index % num_zones]
+
+    commands.append("tc qdisc del dev eth0 root 2> /dev/null || true")
+    commands.append("tc qdisc add dev eth0 root handle 1: htb default 10")
+    commands.append("tc class add dev eth0 parent 1: classid 1:1 htb rate 1gbit")
+    commands.append("tc class add dev eth0 parent 1:1 classid 1:10 htb rate 1gbit")
+    commands.append("tc qdisc add dev eth0 parent 1:10 handle 10: sfq perturb 10")
+
+    handle = 11
+    for zone in header:
+        zone_machines = []
+        for ip in ips:
+            if ip != local_ip:
+                idx = ips.index(ip)
+                z = header[idx % num_zones]
+                if z == zone:
+                    zone_machines.append(ip)
+
+        if not zone_machines:
+            continue
+
+        latency = matrix[local_zone][zone]
+        if latency > 0:
+            delta = latency // 20
+            if delta == 0:
+                delta = 1
+            commands.append(f"tc class add dev eth0 parent 1:1 classid 1:{handle} htb rate 1gbit")
+            commands.append(f"tc qdisc add dev eth0 parent 1:{handle} handle {handle}: netem delay {latency}ms {delta}ms distribution normal")
+            for ip in zone_machines:
+                commands.append(f"tc filter add dev eth0 protocol ip parent 1: prio 1 u32 match ip dst {ip}/32 flowid 1:{handle}")
+            handle += 1
+    return commands
+
+def main():
+    csv_file = sys.argv[1]
+    ip_file = sys.argv[2]
+    local_ip = sys.argv[3]
+
+    header, matrix = read_matrix(csv_file)
+    ips = read_ips(ip_file)
+    commands = build_tc_commands(header, matrix, ips, local_ip)
+
+    for cmd in commands:
+        execute_command(cmd)
+
+if __name__ == "__main__":
+    main()