Architecture & Migration Discussion - What Breaks First and Why

Most ACE on OpenShift discussions assume cloud or virtualized clusters.
But in many banks, refineries, utilities, and industrial plants, OpenShift runs on bare-metal hardware - and that changes everything.

The architecture looks clean on slides.
In reality, hardware decisions leak into integration runtime behavior.

Bare-Metal Foundation Layer

Typical setup

• Dedicated x86 servers (HPE / Dell / Lenovo)

• No hypervisor abstraction

• High-performance NICs

• Local NVMe / SAN-backed storage

• Dual power & network paths

Why enterprises choose bare metal

• Deterministic latency

• Higher throughput

• Regulatory isolation

• OT / plant network integration

But… OpenShift expects cloud-like elasticity. Bare metal doesn't forgive mistakes.

OpenShift Cluster on Bare Metal

Key components

• Control plane nodes

• Worker nodes (often CPU-pinned)

• SR-IOV or bonded NICs

• MetalLB / BGP for ingress

• Local or external storage (ODF / SAN)

Common assumptions that break

• "Pods will reschedule fast" → Not when nodes are pinned

• "Storage is fast" → Not if PVCs are misaligned

• "Network is stable" → Not when MTU mismatches exist

ACE doesn't crash - it waits.

ACE Runtime Layer (Containers)

Deployed as

• Integration Servers / Integration Runtimes

• BAR files packaged into images

• ConfigMaps + Secrets

• Persistent volumes (for stateful flows)

Silent failure zones

• CPU throttling under sustained load

• Memory pressure causing GC stalls

• Disk I/O latency blocking MQ flows

• Pod restarts losing in-memory state

Bare-metal issues surface as "slow flows", not errors.

Networking: The #1 Root Cause

Typical enterprise setup

• Multiple VLANs

• Firewalls between tiers

• OT / IT network segregation

• MTLS everywhere

What breaks

• MTU mismatches (9000 vs 1500)

• Asymmetric routing

• Firewall idle timeouts

• DNS resolution delays

• Service IP vs external IP confusion

Symptoms:

• MQ channels connect but don't transmit

• TCP handshake works, data stalls

• HTTPS calls hang without error

Stop checking ACE logs.Start tracing packets.

Storage & State (Often Ignored)

Where state hides

• Message aggregation

• File-based flows

• Large payload transformations

• Persistent cache patterns

Bare-metal pitfalls

• Local PVs tied to nodes

• SAN latency under load

• PVC reclaim issues

• Pod reschedule = state loss

ACE appears healthy.Messages don't move.

Security Translation Trap (VM → Container)

On VMs

• Filesystem-based keystores

• OS-level certs

• Static user accounts

On OpenShift

• Kubernetes Secrets

• Mounted volumes

• Namespaced isolation

Problem

Secrets exist ≠ ACE uses them

Explicit mapping is mandatory:

• Secrets → ACE credential aliases

• Cert chains → ACE truststores

• MQ certs → container keystore paths

Security migration is never lift-and-shift.

Observability: Where Most Teams Realize They're Blind

Bare-metal failures don't scream.
They whisper.

Without:

• Message-level tracing

• Flow latency metrics

• Correlation IDs

• Node-level telemetry

• AIOps-style analysis

You won't know:

• Where messages stop

• Which hop delays

• Which node throttles

If you can't trace the message,
you can't operate ACE on bare metal.

Key Takeaway

ACE on OpenShift + bare metal is powerful - but unforgiving.

Most failures are:

• Environmental

• Stateful

• Network-driven

• Invisible at pod level

When flows stall:
Don't blame BAR files
Don't restart pods blindly
Instead
Chase the message
Inspect the hardware assumptions

1️What was your first "ACE worked on VM but stalled on bare-metal OpenShift" issue?
2️ Which layer hurt the most - network, storage, or CPU throttling?

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[Karthik kumar] [T] [SVP Technology]
[Cannyfore Technology]
[+91 9600929239]
[karthik.kumar@cannyfore.com]
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