Memory leak issue when running with systemd n send to kafka partition with key

[shasha047]

Describe the bug

1. Memory Leak
2. kafka partition key coming as 8�(� in kafka
3. few warning coming => Sep 06 13:36:01 ccs-122 goflow2[3961852]: time=2025-09-06T13:36:01.765Z level=WARN msg="template error" scheme=netflow hostname="" port=8057 count=1 workers=2 blocking=false queue_size=1000000

** Configs **
Systemd config

[Unit]
Description=GoFlow2 NetFlow Collector on port 8057
After=network.target

[Service]
ExecStart=/opt/netflow/bin/goflow2
-mapping=/opt/netflow/config/mapping_8057.yaml
-transport=kafka
-transport.kafka.brokers=10.10.10.122:9093
-transport.kafka.topic=netflow
-transport.kafka.hashing
-listen=netflow://:8057
-addr=:18057

WorkingDirectory=/opt/netflow
Restart=always
RestartSec=5
User=root
Group=root
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

cat /opt/netflow/config/mapping_8057.yaml

formatter:
type: json
key:
- sampler_address

mapping:

• output: sampler_address
  value: "$sampler_address"

To Reproduce
Steps to reproduce the behavior:

1. Run systemd service with systemctl commands
2. run traffic using tcp replay or actual router via some other machine
3. check : systemd-cgtop => memory keep growing

Expected behavior
A clear and concise description of what you expected to happen.

1. kafka patition key should be correct
2. no memory leak

GoFlow2:

• Version: latest: v2.2.3
• Environment: systemd
• OS: Ubuntu 22.04 jammy