ClickHouse DBA Support Archives

ClickHouse Upgrade Guide: 6 Proven Steps for Zero-Downtime Rolling LTS Upgrades

A production ClickHouse upgrade done properly is a rolling, replica-by-replica operation with zero query downtime, a measured before/after regression check, and a rollback posture decided before the first package is installed. Done casually, it is […]

ClickHouse Ingestion Performance: Batch Sizing, Async Inserts, and Kafka Pipelines

ChistaDATA Inc.

ClickHouse ingestion performance is decided long before the query planner ever touches your data. It is decided by how many parts your writers create per second, how much background merge work those parts generate, and […]

ClickHouse Merge Performance: Diagnosing Too Many Parts, Slow Merges, and Stuck Mutations

ChistaDATA Inc.

ClickHouse merge performance is the hinge on which every high-ingest MergeTree deployment turns. When background merges keep pace with inserts, part counts stay flat and SELECT latency stays predictable. When they fall behind, the failure […]

ClickHouse MergeTree Optimization: Sort Keys, Partitioning, Skip Indexes, and Projections

ChistaDATA Inc.

ClickHouse MergeTree optimization is the difference between a table that answers analytical queries in milliseconds and one that scans hundreds of gigabytes for every request. This guide is written for senior engineers who already understand […]

ClickHouse Query Performance Tuning: A Production Diagnostic Playbook

ChistaDATA Inc.

Effective ClickHouse query performance tuning is less about magic settings and more about a repeatable diagnostic loop: measure, read the plan, isolate the bottleneck, change one variable, and re-measure. This playbook is written for senior […]

ClickHouse Performance Observability and Monitoring: A Complete Whitepaper

ChistaDATA Inc.

ClickHouse performance observability and monitoring is the discipline of measuring, visualizing, and continuously improving how a ClickHouse cluster behaves under real-world workloads. As organizations adopt ClickHouse to power sub-second analytics over petabyte-scale datasets, the gap […]

20 Things You Should Not Do With ClickHouse Which Will Destroy ClickHouse Performance

ChistaDATA Inc.

ClickHouse is one of the fastest open source columnar databases for real-time analytics, and it powers observability platforms, product analytics, and large-scale reporting workloads across the industry. Yet raw speed can be deceptive. Many teams […]

ClickHouse Hot Spot Detection and Remediation in Clusters

ChistaDATA Inc.

In large-scale analytical systems, uneven data distribution is one of the most insidious performance killers. When certain nodes in a ClickHouse cluster receive disproportionately high volumes of reads or writes, those nodes become hot spots […]

Mining the ClickHouse Query Log for Performance Insights

ChistaDATA Inc.

ClickHouse query log: a practical look at how it works, what to tune, and the pitfalls that trip up production ClickHouse.

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ClickHouse Disk and Memory Alerting: Signals That Catch Outages Early

ChistaDATA Inc.

ClickHouse disk and memory alerting: a practical look at how it works, what to tune, and the pitfalls that trip up production ClickHouse.

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