Categories

Jacar categories — explore the topics A rocket whose eyes follow your cursor.
Architecture

Kubernetes 1.35 GA: an operations-side balance sheet

Kubernetes 1.35 GA consolidates three releases of work: native sidecars with full lifecycle management, generalised DRA for FPGAs and NPUs, and a scheduler that cuts resource waste by 15-25% in heterogeneous clusters. An operations-side balance sheet: what to enable now, what to watch before migrating, and what path to follow from 1.30.

Architecture

MCP as multi-vendor standard: patterns already mature

The Model Context Protocol, proposed by Anthropic in late 2024 and adopted through 2025-2026 by Anthropic, OpenAI, Google, and the open-source community, already has proven operational patterns: separating generic servers from custom ones, explicit per-tool policies, credentials kept outside the model, prefixed composition, and contract tests. This is the state of the art in 2026.

Architecture

Hybrid RAG in 2026: the patterns that keep winning

Hybrid RAG in 2026 combines dense and lexical search fused with RRF, cross-encoder reranking over the top-50 candidates, structure-aware chunking, and continuous evaluation with Ragas or TruLens. It is the pattern that survives in serious production systems three years after the initial embeddings boom.

Architecture

Agent OS: the concept shaping the new stack layer

The term Agent OS has spent a year gaining traction across research and product circles. It describes a layer that goes well beyond an agent library: request scheduling, context management, persistent memory, and isolation. A look at the real state of that concept.

Architecture

Kubernetes 1.34: a summary for teams with little time

Kubernetes 1.34 ships with Dynamic Resource Allocation (DRA) graduating to stable, scheduler improvements, and CEL-based mutating admission policies that replace webhooks. A practical rundown of what is safe to upgrade now, what can wait, and what actually changes for teams running production clusters.

Architecture

Container Monitoring: Beyond cAdvisor

cAdvisor is still embedded in kubelet and covers surface metrics, but falls short for production Kubernetes. The modern minimum stack pairs it with kube-state-metrics, node-exporter, Prometheus, and Grafana as a base, eBPF for deep network and syscall visibility, and OpenTelemetry for application context.

Architecture

Cilium Service Mesh: When You Don’t Need Sidecars

Cilium Service Mesh replaces Istio or Linkerd sidecars with eBPF in the kernel: it handles policy, WireGuard encryption, and Hubble observability without a per-pod proxy, cutting memory overhead from roughly 100 GB to about 5 GB in a 100-node cluster. It suits large clusters with teams comfortable with eBPF.

Architecture

Backstage, Port and Cortex: Three Paths to the IDP

An Internal Developer Platform (IDP) centralises service discovery, provisioning and observability in a single portal, so developers stop depending on stale wikis and Slack channels. Backstage, Port and Cortex dominate the market: Backstage is open source with a dedicated team, Port is fast low-code SaaS, and Cortex focuses on scorecards for measurable technical discipline based on team size.

Architecture

SQLite and DuckDB: When Each Is the Right Choice

SQLite and DuckDB are both embedded databases that work from a single file, no server needed. Their architecture differs: SQLite stores rows and excels at short transactions (OLTP); DuckDB stores columns and shines at large-scale analytics (OLAP). Choosing the right one, or combining both, delivers a genuine technical edge.

Architecture

Service Mesh in 2023: Istio, Linkerd, and the Cilium Option

A service mesh adds mTLS, uniform observability, and traffic management between microservices without modifying application code. The ecosystem has consolidated: Istio is the most complete and complex, Linkerd prioritises simplicity with Rust proxies, and Cilium delivers sidecarless service mesh via eBPF.

Architecture

Kubernetes 1.27: The Changes That Matter to Operators

Kubernetes 1.27 ("Chill Vibes"), released in April 2023, makes SeccompDefault stable so pods get safer syscall defaults automatically, moves KMS v2 to beta with rotatable encryption keys for etcd secrets, and stabilises scheduling gates. It also removes PodSecurityPolicy for good: without migrating to Pod Security Admission first, the upgrade is blocked entirely.

Architecture

Kafka in 2023: Event Streaming in the Enterprise

Apache Kafka has consolidated in 2023 as the enterprise event backbone thanks to KRaft, now GA and removing the ZooKeeper dependency. The most mature patterns are CDC with Debezium, event sourcing, and stream processing with Kafka Streams or Flink, while Redpanda and Pulsar compete as real alternatives depending on the case.

Architecture

OpenTelemetry: Unifying Logs, Metrics, and Traces

OpenTelemetry is the CNCF project, graduated in May 2026, that unifies logs, metrics, and traces under one SDK and the OTLP protocol, without locking you into a single backend. Traces have been stable since 2021 and metrics since 2023; logs are still maturing, but already worth adopting on new projects.

Architecture

Cilium and the Future of Container Networking with eBPF

Cilium replaces iptables with eBPF programs loaded directly into the Linux kernel, substituting O(n) linear chains with O(1) hash lookups. Documented benchmarks show up to 50% lower p95 latency, 2-3x more throughput, and 70% less kernel CPU in large Kubernetes clusters.

Architecture

RabbitMQ for Message Queues: When It’s Still the Choice

Kafka gets the headlines as the byword for modern messaging, but RabbitMQ remains the better choice for task queues with retries, asynchronous RPC, and pub/sub with complex routing. This guide compares both against NATS, walks through classic patterns and production mistakes, and helps you decide based on the actual use case rather than the trend.

Architecture

Kubernetes 1.28: Sidecar Containers as First-Class Citizens

Kubernetes 1.28 introduces native sidecar containers in alpha via KEP-753: adding restartPolicy Always to initContainers ensures correct startup and shutdown ordering. It fixes Jobs that never terminate. Istio, Linkerd, and observability agents like Fluent Bit are the primary beneficiaries.

Architecture

Modules vs. Microservices: The Architecture Battle

Choose modular architecture when your team has fewer than ten people and ships the system as a single unit; choose microservices when separate teams need to deploy independently or when specific components require very different scaling, in exchange for higher operational complexity.