Overview of Big Bang v3 Migration in SmoothGlue
The upcoming SmoothGlue 6.18 release, scheduled for the week of June 25th, 2025, marks a pivotal moment for our platform. This release incorporates a major version bump for Big Bang, moving from 2.X to 3.X, alongside a significant enhancement to our observability stack. These changes are designed to improve system stability, align with upstream best practices, and provide a more robust and efficient platform for your applications.
This document provides a high-level overview of these changes, outlining the key impacts and what platform operators need to know to ensure a smooth transition. For detailed technical guidance, please refer to the dedicated documentation linked within this overview.
SmoothGlue Release Cadence Leading to 6.18
To ensure a gradual and well-tested transition, we are introducing these significant updates incrementally across several SmoothGlue releases:
SmoothGlue 6.16 (Week of May 28th, 2025)
Focus: Laying the Groundwork for Modern Observability and Istio Transition
- Big Bang Version:
2.53.1 - Key Changes:
- Operator-less Istio Migration (Beta): We're introducing support for the Operator-less Istio migration as a beta feature. This is a critical step in preparing for Big Bang 3.0, where the Istio Operator will be deprecated. While disabled by default in
6.16, it allows platform operators to begin testing and validating this significant architectural shift in their test/staging environments. - Alloy Replaces Promtail (Enabled by Default): Our logging and telemetry collection is getting a significant upgrade. Alloy is now enabled by default and replaces Promtail, which has been deprecated. This transition offers enhanced capabilities for collecting metrics, logs, traces, and profiles, aligning with the OpenTelemetry standard and reducing operational overhead.
- Operator-less Istio Migration (Beta): We're introducing support for the Operator-less Istio migration as a beta feature. This is a critical step in preparing for Big Bang 3.0, where the Istio Operator will be deprecated. While disabled by default in
SmoothGlue 6.17 (Week of June 11th, 2025)
Focus: Refining and Stabilizing for Big Bang 3.0
- Big Bang Version:
2.54.X - Key Changes:
- Last Big Bang
2.XRelease: This release serves as the final iteration of Big Bang2.X, focusing on addressing any bugs or issues identified during the beta testing of the Operator-less Istio migration. This ensures a stable foundation before the full3.0adoption.
- Last Big Bang
SmoothGlue 6.18 (Week of June 25th, 2025)
Focus: Full Adoption of Big Bang 3.0 and Operator-less Istio
- Big Bang Version:
3.0.x - Key Changes:
- Operator-less Istio Migration Enabled by Default: The Operator-less Istio migration becomes the default behavior in SmoothGlue
6.18. The legacy Istio operator will be automatically removed post-migration, simplifying the Istio deployment and management. - Full Transition to Alloy: Promtail is fully deprecated and removed, with Alloy becoming the sole agent for telemetry data collection.
- Operator-less Istio Migration Enabled by Default: The Operator-less Istio migration becomes the default behavior in SmoothGlue
Key Initiatives in SmoothGlue 6.18
1. Big Bang 3.0 - Operator-less Istio Migration
Why this matters: The upstream Istio project announced the deprecation of the Istio Operator in August 2024. In response, Big Bang 3.0 deprecates the Istio Operator, moving to a more streamlined and maintainable native Helm chart deployment. This change enhances long-term stability and aligns SmoothGlue with the latest Istio architectural recommendations.
Impact on Platform Operators: While SmoothGlue automates the core migration process, there are a few important considerations:
- Testing is Crucial: We highly recommend enabling and testing the Operator-less Istio feature in your test/staging clusters with SmoothGlue
6.16or6.17. - Potential Downtime: Be aware that the Istio gateways will be recreated in a new namespace during the migration, leading to some brief downtime for applications using built-in gateways.
- Custom Application Adjustments (if applicable): If you have custom applications that utilize built-in Istio gateways, some pre-migration manual steps are required to update their configurations. We have provided clear guidance to minimize disruption.
What SmoothGlue Automates: The vast majority of the migration process is handled automatically by SmoothGlue. Manual steps are only required for specific custom application configurations.
For Detailed Technical Steps: Please refer to the comprehensive guide: Big Bang 3.0 - Operator-less Istio Migration
2. Enhanced Observability: Migration from Promtail to Alloy
Why this matters: Promtail is being deprecated by the upstream Big Bang project, with all future development for log collection shifting to Grafana Alloy. Alloy is a more powerful and versatile agent, based on the OpenTelemetry Collector, capable of collecting a broader range of telemetry signals (metrics, logs, traces, profiles) with a single agent. This transition provides a more unified and future-proof observability solution for SmoothGlue.
Impact on Platform Operators:
- Automatic Transition: SmoothGlue will automatically disable Promtail and enable Alloy by default when upgrading to SmoothGlue
6.16. - Custom Promtail Configurations: If you have custom configurations for Promtail, you will need to utilize the Grafana Alloy migration utility to assist with the transition.
What SmoothGlue Automates: SmoothGlue manages the default transition from Promtail to Alloy. Only custom Promtail configurations require manual intervention.
For Detailed Technical Steps: Please refer to the Release Notes for SmoothGlue 6.16, which will include specific guidance on migrating custom Promtail configurations.