---
title: "Istio"
description: "2 posts about Istio, summarised, each linking to the original."
---

# Istio
> 2 posts about Istio, summarised, each linking to the original.

## Articles

### [Replica-aware routing public beta](https://yomu.fyi/post/replica-aware-routing-public-beta.md)
- Company: [Clickhouse](https://yomu.fyi/company/clickhouse.md)
- Published: Sep 15, 2026
- Type: Announcement

ClickHouse’s replica-aware routing is now in Public Beta for Enterprise customers, addressing cases where temporary tables and named sessions become invisible after a request reaches another replica. The feature routes requests to a consistent replica using an X-ClickHouse-Replica-Tag or a native TLS SNI override, supporting session-scoped access and read-after-write consistency. Over HTTP, Envoy reads the header and uses consistent hashing; native connections decouple the SNI used for routing from the hostname validated against the certificate. Stickiness is best-effort and can change after upgrades, restarts, or scaling, so temporary objects and session settings may need recreation. The feature is available through service settings for Enterprise plans on standard ClickHouse Cloud and BYOC.


### [Grab's service mesh evolution: From Consul to Istio](https://yomu.fyi/post/grab-s-service-mesh-evolution-from-consul-to-istio.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Hilman Kurniawan
- Published: Jul 16, 2025
- Type: Problem & solution

Grab describes migrating its service mesh from Consul and the Catcher fallback across a microservices ecosystem of more than 1,000 services spanning VMs, EKS clusters, AWS, and GCP. The existing setup exposed fleet-wide risk from a single Consul server issue, added fallback complexity, and lacked advanced traffic management, security controls, and robust multi-cluster support. After evaluating Application Load Balancer, Istio, AWS Lattice, and Linkerd for stability, performance, integration, and operational simplicity, the team selected Istio for its Kubernetes integration, flexible deployment models, and feature set. The design uses multiple control planes on dedicated Kubernetes clusters, active-active pairs, organization-based mesh boundaries, custom resource definitions, and cross-cluster endpoint discovery to support isolation, availability, routing, security, and observability. Migration began in Q4 2024 with GCP-to-AWS work alongside gRPC and HTTP traffic initiatives, using gradual shifting, rollback mechanisms, and performance monitoring while teams manage legacy systems and cross-mesh connectivity.