Thanos 0.34: Prometheus High Availability Excellence

Introduction

Prometheus is excellent until you need two things at once: high availability (no blind spots when an instance dies) and long-term retention (weeks/months of metrics for capacity planning and compliance). Thanos is the “make Prometheus scale” layer—storage, global query, and deduplication.

Thanos 0.34, released on December 15, 2025, improves the core concerns that show up in production: object storage behavior, query performance, and reliability characteristics for large deployments.

Why this matters in practice

• Faster global queries: query performance improvements matter when dashboards fan out across many stores.
• Smoother retention: better compaction/downsampling reduces the operational load of long-term metrics storage.
• More reliable HA: improved deduplication and failure handling reduces gaps during Prometheus outages.

Long-Term Storage

• Object storage improvements provide better integration with S3, GCS, Azure Blob, and other object storage backends with improved performance.
• Compaction enhancements optimize storage usage and query performance with better compaction strategies and scheduling.
• Retention policies enable more flexible data retention configuration with automatic data deletion and lifecycle management.
• Downsampling improvements enable efficient storage of historical data with configurable downsampling resolutions.

Query Performance

1. Query optimization improvements reduce latency for metric queries by up to 50% through better query planning and execution.
2. Caching enhancements provide better response times for frequently accessed metrics with intelligent result caching.
3. Deduplication improvements enable better handling of multiple Prometheus instances with improved deduplication algorithms.
4. Concurrent query processing enables better handling of multiple queries with parallel execution and resource management.

Reliability Improvements

• Replication enhancements provide better data durability with improved replication strategies and consistency guarantees.
• Backup capabilities enable efficient backup and restore operations for disaster recovery scenarios.
• Recovery mechanisms enable automatic recovery from failures with health checks and automatic repair.
• Health checking improvements provide comprehensive visibility into system health with detailed status reporting.

Integration Capabilities

1. Prometheus integration improvements provide seamless integration with Prometheus with better compatibility and feature support.
2. Grafana enhancements enable better visualization of metrics from Thanos with improved query support and performance.
3. Alerting integration enables alerting based on long-term metrics with support for Prometheus alerting rules.
4. Multi-tenancy support enables secure multi-tenant deployments with namespace isolation and resource quotas.

Getting Started

# Install Thanos using Helm
helm repo add thanos https://charts.bitnami.com/bitnami
helm install thanos thanos/thanos \
  --set objstore.config.type=S3 \
  --set objstore.config.config.bucket=thanos-storage

Summary

Thanos 0.34 continues to be the leading solution for Prometheus high availability, providing teams with unlimited metric retention, global querying, and reliable long-term storage for monitoring data.