How to Pinpoint Packet Loss in Cloud‑Native Deployments with SysOM

Background

In cloud‑native environments, packet loss directly impacts service continuity: even mild loss can break health checks, cause ping failures, and trigger cascading operational incidents. Rapid identification of the loss source is therefore essential for maintaining business uptime.

Case 1 – Rapid problem bounding

A customer deploying a distributed ACK cluster in a new region observed node‑to‑node communication failures that halted deployment. Using the OS Console’s SysOM intelligent diagnosis, the fault was isolated within a few hours.

Investigation steps

Compared iptables rules on healthy and faulty nodes – no differences found.

Ran the built‑in kernel packet‑loss test from the OS console; kernel reported no loss.

Inspected network hook logs and discovered unexpected sched_cls hooks injected by a network component.

Unloaded the suspect component, which immediately restored health‑check connectivity.

Case 2 – Precise issue localization

Another client could not connect to port 1678 on a newly created instance, while SSH (port 22) worked. Service processes were listening and firewall rules appeared clean.

Key diagnostic workflow

Execute the OS console’s packet‑loss diagnostic and review the generated report.

If the kernel shows no loss, verify that no unexpected security software or hook modules are loaded.

Check iptables and nftables configurations for drop rules.

When needed, use tracing tools such as funcgraph or eBPF to instrument the packet path and pinpoint drops.

Technical details of the SysOM workflow

The OS console provides a step‑by‑step UI for network diagnosis:

Select the target ECS instance in ECS Insight → SysOM → Node Diagnosis → Network Diagnosis → Packet‑Loss Diagnosis .

Run the diagnostic; the console collects kernel statistics, netfilter tables, and hook logs.

Review the report: it indicates whether loss occurs at the kernel level, in netfilter (iptables/nftables), or in user‑space hooks.

If a netfilter rule is flagged, inspect nft list ruleset (or iptables -L -v -n) and remove the offending drop rule, e.g.

nft delete rule ip filter input ip dport 1678 drop

.

If hook modules are present, list loaded kernel modules ( lsmod) and unload the suspicious one ( modprobe -r <em>module_name</em>) or disable the associated service.

Summary

Network packet‑loss incidents in cloud‑native workloads can be resolved efficiently by following a systematic SysOM workflow: start with the built‑in packet‑loss test, then verify firewall configurations, examine netfilter rules, and finally inspect kernel hooks or driver modules. This approach isolates the root cause quickly, minimizes downtime, and avoids extensive manual kernel debugging.