Unified Cloud-Native Observability & High-Availability Distributed Storage
Full-stack Prometheus, Grafana, Alertmanager, and Loki telemetry paired with self-healing Ceph & Longhorn storage for 99.9% SLA workloads
Senior Site Reliability & Platform Engineer
99.9% SLA
Sustained 24/7 high availability across hybrid microservices and stateful data infrastructure.
Single Pane
Unified metrics, logs, and storage telemetry in Grafana to slash incident Mean Time to Resolution (MTTR).
Self-Healing
Automated storage replica rebuilds and failover using Ceph and Longhorn distributed storage engines.
01 // Engineering Problem
Stateful applications and high-throughput microservices suffered from fragmented log/metric visibility during incidents and lacked resilient, cloud-native persistent block/object storage on bare-metal and hybrid Kubernetes clusters.
02 // Business & Operational Context
Sustaining a 99.9% production SLA for 24/7 platforms required correlating metrics, logs, and alerts in a single pane of glass while ensuring stateful workloads (databases, queues, registries) survived node and disk failures without data loss.
Architecture Topology // Unified Cloud-Native Observability & High-Availability Distributed Storage
Prometheus + Alertmanager
ServiceMonitors, node-exporter, kube-state-metrics, and PromQL recording rules driving actionable SLO alerts.
Grafana Loki + Promtail
Label-indexed centralized log ingestion across all namespaces without full-text Elasticsearch overhead.
SUSE Longhorn CSI
Cloud-native distributed block storage with synchronous multi-node volume replicas and S3 backup targets.
Ceph Cluster (Ansible)
Self-healing distributed RBD block, CephFS shared file, and RGW object storage for Kubernetes and VMs.
Mermaid Topology Specification (Architecture-as-Code) ▼
flowchart LR
subgraph Workloads["Stateful & Microservice Workloads (99.9% SLA)"]
Apps["Microservices & APIs\n(70% Microservices / 30% Monoliths)"]
Data["Stateful Data Layer\n(MySQL, Kafka, Cassandra, Harbor)"]
end
subgraph Storage["Self-Healing Distributed Storage"]
Longhorn["SUSE Longhorn CSI\n(3x Replicated Block Volumes)"]
Ceph["External Ceph Cluster\n(RBD Block + CephFS + RGW Object)"]
end
subgraph Obs["Unified Observability Stack"]
Prom["Prometheus + Alertmanager\n(Golden Signals & SLO Burn Alerts)"]
Loki["Grafana Loki + Promtail\n(Centralized Pod & Node Logs)"]
Graf["Grafana Dashboards\n(Metric-to-Log Correlation)"]
end
Data --> Longhorn & Ceph
Apps & Data --> Prom & Loki
Storage --> Prom
Prom & Loki --> Graf Key Architectural Decisions & Engineering Tradeoffs
DECISION 01
Adopt Grafana Loki paired with Prometheus instead of heavy ELK stacks for Kubernetes log aggregation
Loki indexes only Kubernetes metadata labels (namespace, pod, container, app) matching Prometheus labels, enabling instant metric-to-log drilldowns at a fraction of the RAM and storage cost.
Ad-hoc regex queries over massive unindexed log ranges require LogQL filter optimization.
DECISION 02
Combine Longhorn for lightweight in-cluster block storage and External Ceph for high-capacity multi-cluster storage
Longhorn provides turn-key Kubernetes-native block replication for standalone clusters, while Ansible-managed external Ceph scales to petabyte RBD/CephFS/S3 workloads shared across multiple clusters.
External Ceph requires dedicated storage network bandwidth (10GbE+) and OSD disk layout planning.
Zero-Trust Security Guardrails
- Ceph Cephx authentication and isolated storage network VLANs for OSD replication traffic.
- RBAC-restricted Grafana data sources and encrypted persistent volume classes.
SRE & Reliability Engineering
- 3x synchronous replica factor across failure domains in both Longhorn and Ceph OSD pools eliminates single-node disk failure impact.
- Proactive disk saturation, inode exhaustion, and etcd fsync latency alerts routed through Alertmanager.
Engineering Challenge
Running stateful workloads and high-traffic SaaS microservices on Kubernetes introduces two recurring failure modes:
- Observability Silos: Metrics live in one tool while container logs require SSHing or running
kubectl logsacross dozens of pods during an outage. - Stateful Persistence on Bare-Metal/Hybrid Nodes: Local hostPath volumes tie pods to a single node, causing immediate downtime if a worker host fails.
Solution Architecture
1. Metric-to-Log Correlation with Prometheus, Grafana & Loki (monitoring-stack-kuberntes)
We deployed the unified kube-prometheus-stack alongside Grafana Loki:
- Metrics: Prometheus scrapes
kube-state-metrics,node-exporter, cAdvisor, CNI, and storage CSI metrics. - Logs: Promtail DaemonSets tail
/var/log/pods/*, attaching identical Kubernetes labels (namespace,pod,app) so engineers can pivot from a Prometheus latency spike directly to the exact pod log lines in Grafana.
2. Resilient Distributed Storage with Ceph & Longhorn
- External Ceph via Ansible (
ceph-ansible): Automated deployment of Ceph Monitor (mon), Manager (mgr), and Object Storage Daemon (osd) nodes providing self-healing RBD block volumes and CephFS shared file systems. - Longhorn Cloud-Native Storage (
longhorn): Deployed via Helm with 3x synchronous volume replication across worker nodes and automated snapshot backups.