Posts in 2026
Cortex Security Audit Results
Tuesday, July 07, 2026 in Blog
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Introduction The Cortex maintainer team is publishing the results of a third-party security audit of the Cortex codebase, completed on April 20, 2026. Cortex is a horizontally scalable, multi-tenant, long-term storage backend for Prometheus. …
Posts in 2025
Introducing READONLY State: Gradual and Safe Ingester Scaling
Friday, October 17, 2025 in Blog
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Introduction Scaling down ingesters in Cortex has traditionally been a complex and risky operation. The conventional approach required setting querier.query-store-after=0s, which forces all queries to hit storage directly, significantly impacting …
Query Priority in Cortex
Monday, September 08, 2025 in Blog
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Introduction In high-scale monitoring environments, not all queries are created equal. Some queries power critical dashboards that need sub-second response times, while others are exploratory analytics that can tolerate delays. However, the queries …
Efficient Query Parallelism in Cortex with Dynamic Query Splitting
Tuesday, August 12, 2025 in Blog
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Introduction Cortex traditionally relied on static query splitting and static vertical sharding to optimize the execution of long-range PromQL queries. Static query splitting divides a query into fixed time intervals, while vertical sharding—when …
Block the Blast: How Query Rejection Protects Your Cortex Cluster
Monday, August 04, 2025 in Blog
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Introduction Although Cortex includes various safeguards to protect against overload, they can’t prevent every failure scenario. In some environments, a small set of seemingly harmless-looking dashboard queries have repeatedly slipped just under the …
Optimizing PromQL queries: A deep dive
Tuesday, April 29, 2025 in Blog
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Introduction This guide explains how Cortex evaluates PromQL queries, details how time series data is stored and retrieved, and offers strategies to write performant queries — particularly in high-cardinality environments. Note: If you are new to …
Introducing the Cortex Blog: Sharing Our Journey
Saturday, April 26, 2025 in Blog
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Welcome to the official Cortex blog! We’re kicking things off here to share updates, best practices, technical deep-dives, and community highlights around everything Cortex. Whether you’re operating a Cortex cluster, integrating it into your …