# =============================================================================
#  settings.conf - every tunable value for the DHCP kit, in one place
# =============================================================================
#  Both start-dhcp.sh and test-dhcp.sh read this file.
#  After changing a value in sections 1-3, run ./start-dhcp.sh again so the
#  DHCP server picks it up.
#
#  Any value can also be overridden for a single run from the command line:
#      DURATION=30 ./test-dhcp.sh throughput
# =============================================================================


# -----------------------------------------------------------------------------
#  1. The private test network
# -----------------------------------------------------------------------------
#  The test never uses a real network card. start-dhcp.sh creates a virtual
#  cable (a "veth pair") with two ends:
#
#     DHCP server (dhcpd)                         simulated DHCP clients
#     [ SERVER_IFACE  10.199.0.1 ] <=========> [ CLIENT_IFACE ]
#       normal host network                    inside network namespace TEST_NETNS
#
#  dhcpd listens ONLY on SERVER_IFACE, so it can never answer clients on the
#  real network. Pick a subnet that is not used anywhere on your network.
TEST_NETNS="${TEST_NETNS:-dhcp-perf}"          # network namespace for the clients
SERVER_IFACE="${SERVER_IFACE:-dhcp-srv}"       # server end of the virtual cable (max 15 chars)
CLIENT_IFACE="${CLIENT_IFACE:-dhcp-cli}"       # client end of the virtual cable (max 15 chars)

SUBNET="${SUBNET:-10.199.0.0}"
NETMASK="${NETMASK:-255.255.0.0}"
PREFIX_LENGTH="${PREFIX_LENGTH:-16}"           # the same netmask, written as /16
SERVER_IP="${SERVER_IP:-10.199.0.1}"
CLIENT_IP="${CLIENT_IP:-10.199.0.2}"           # used only as the sender address

# Addresses the server hands out: 32766 addresses.
POOL_START="${POOL_START:-10.199.128.1}"
POOL_END="${POOL_END:-10.199.255.254}"


# -----------------------------------------------------------------------------
#  2. Files and service used on the server
# -----------------------------------------------------------------------------
#  The kit does NOT touch the normal dhcpd.service or /etc/dhcp/dhcpd.conf.
#  It runs the same RHEL dhcpd program as its own systemd service, with its
#  own configuration and lease file. "./start-dhcp.sh cleanup" removes them.
TEST_SERVICE="dhcpd-perf-test"                                   # systemd service name
TEST_UNIT_FILE="/etc/systemd/system/${TEST_SERVICE}.service"
TEST_CONF="/etc/dhcp/dhcpd-perf-test.conf"                       # dhcpd configuration
TEST_LEASES="/var/lib/dhcpd/dhcpd-perf-test.leases"             # dhcpd lease database
TEST_PIDFILE="/run/dhcpd-perf-test.pid"                          # used only without systemd


# -----------------------------------------------------------------------------
#  3. dhcpd settings
# -----------------------------------------------------------------------------
LEASE_TIME="${LEASE_TIME:-3600}"               # seconds a lease is valid (default)
MAX_LEASE_TIME="${MAX_LEASE_TIME:-7200}"       # longest lease a client may ask for


# -----------------------------------------------------------------------------
#  4. How hard and how long each test runs
# -----------------------------------------------------------------------------
DURATION="${DURATION:-10}"                     # seconds of load for each test run

# "throughput": this many clients are in the middle of getting a lease at
# any moment. Each starts again as soon as it has its lease (maximum speed).
OUTSTANDING="${OUTSTANDING:-50}"

# "latency", "loss", "cpu", "memory", "leasedb": a steady, realistic load of
# LOAD_RATE new clients per second.
LOAD_RATE="${LOAD_RATE:-200}"

# "scaling": the steady load is raised step by step through these rates.
RATE_LEVELS="${RATE_LEVELS:-250 500 1000 2000 4000 8000 16000}"
SCALING_LOSS_LIMIT_PCT="${SCALING_LOSS_LIMIT_PCT:-1}"   # a step "keeps up" if loss <= this

# "renew": this many clients get a lease, then renew it again and again.
RENEW_CLIENTS="${RENEW_CLIENTS:-1000}"

# Different simulated clients (MAC addresses) to cycle through. Must be
# smaller than the address pool (32766), so the pool never runs out.
MAC_POOL_SIZE="${MAC_POOL_SIZE:-20000}"

# Every test run adds records to the lease file (a full run: about 140 MB).
# "yes" empties the test lease file at the start of each run, so every run
# starts from the same point and results can be compared.
RESET_LEASES_BEFORE_TEST="${RESET_LEASES_BEFORE_TEST:-yes}"

EXCHANGE_TIMEOUT="${EXCHANGE_TIMEOUT:-2}"      # seconds to wait for an answer before "lost"
STARTUP_ROUNDS="${STARTUP_ROUNDS:-3}"          # restarts measured by the "startup" test


# -----------------------------------------------------------------------------
#  5. Pass / fail targets
# -----------------------------------------------------------------------------
#  These are sensible starting points for a RHEL 9 server that serves a
#  network of a few thousand clients. Adjust them to your own needs. A result
#  that misses its target is reported as FAIL; see PERFORMANCE-METRICS.md for
#  what each number means.
TARGET_STARTUP_MAX_MS="${TARGET_STARTUP_MAX_MS:-3000}"          # start until first OFFER
TARGET_THROUGHPUT_MIN_LPS="${TARGET_THROUGHPUT_MIN_LPS:-1000}"  # new leases/second, at least
TARGET_LATENCY_P95_MAX_MS="${TARGET_LATENCY_P95_MAX_MS:-10}"    # 95% of lease exchanges faster than
TARGET_LATENCY_P99_MAX_MS="${TARGET_LATENCY_P99_MAX_MS:-50}"    # 99% of lease exchanges faster than
TARGET_LOSS_MAX_PCT="${TARGET_LOSS_MAX_PCT:-0.1}"               # failed exchanges at LOAD_RATE, at most %
TARGET_CAPACITY_MIN_LPS="${TARGET_CAPACITY_MIN_LPS:-1000}"      # highest rate kept up with, at least
TARGET_RENEW_MIN_RPS="${TARGET_RENEW_MIN_RPS:-1000}"            # renewals/second, at least
TARGET_CPU_MAX_PCT="${TARGET_CPU_MAX_PCT:-50}"                  # % of ONE core at LOAD_RATE
TARGET_MEMORY_MAX_MB="${TARGET_MEMORY_MAX_MB:-256}"             # dhcpd memory, at most