Sfd V1.23 [2026]

Always backup the binary and configuration directory:

sudo cp $(which sfd) /opt/sfd-v1.22.backup
sudo cp -r /etc/sfd /etc/sfd.backup

While SFD v1.23 is stable, the following known issues remain unresolved and are scheduled for future patches:

The default configuration file (/etc/sfd/sfd.conf) has changed in v1.23. Key directives to review:

# /etc/sfd/sfd.conf for v1.23
global:
  tls_min_version: TLSv1.3
  congestion_control: acc
  compression: zstd
  compression_level: 9
  atomic_writes: true
limits:
max_connections: 1000
transfer_timeout_seconds: 3600 sfd v1.23
logging:
output: /var/log/sfd/access.log
format: json  # new in v1.23

To enable Zstandard dictionary compression for repetitive data (e.g., VM images), generate a dictionary: Always backup the binary and configuration directory: sudo

sfd train-dictionary --input /sample/dataset/ --output /etc/sfd/dict.zst

Then reference it in the config under compression_dict: /etc/sfd/dict.zst.

Because of the deprecation of --legacy-ipc, you may need to update your init scripts or systemd unit files:

# Old ExecStart line
ExecStart=/usr/bin/sfd --legacy-ipc --config /etc/sfd/config.json
Previous versions used fixed-interval heartbeats for service health checks. SFD v1.23 introduces an adaptive algorithm that extends heartbeat intervals during low activity and shortens them during transaction bursts. This reduces network chatter by 25% on average while maintaining sub-second failure detection. While SFD v1
For advanced users, v1.23 exposes eBPF hooks that allow custom observability scripts without recompiling the daemon. You can now attach probes to function entry/exit points and export metrics directly to Prometheus or OpenTelemetry collectors.
Example use case:
sudo sfd probe attach --event tcp_receive --script monitor_bandwidth.bpf