Our billing pipeline was suddenly slow
Cloudflare experienced a slowdown in its billing pipeline due to a hidden bottleneck in ClickHouse. This issue arose after a migration and impacted the timely processing of billing jobs, which are crucial for revenue generation. The company implemented three patches to address the performance issues and improve their data retention policies.
- ▪Cloudflare relies heavily on ClickHouse for billing and analytics, processing millions of calls daily.
- ▪A hidden bottleneck was discovered in ClickHouse's internals, causing delays in daily aggregation jobs.
- ▪The company adopted a new partitioning scheme to allow per-namespace retention, improving data management.
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Story provenance
Attribution is not the same as permission. This drawer separates discovery metadata, excerpts, WeSearch-generated summaries, reuse status, and whether the publisher receives the visit. Nothing here claims a legal grant the publisher has not made.
Record
| Original publisher | Cloudflare Blog |
| Canonical URL | https://blog.cloudflare.com/clickhouse-query-plan-contention/ |
| Publication time | Thu, 21 May 2026 01:14:06 +0000 |
| Retrieval time | 2026-05-21T01:35:03.222Z |
| Last seen | 2026-05-21T01:35:03.222Z |
| Headline source | Publisher (no WeSearch rewrite) |
| Excerpt source | publisher body |
| Excerpt method | First ~120 words (~800 chars) of extracted publisher body, fair-use limited. |
| Summary | WeSearch · cerebras-chat (WeSearch summarizer) |
| Summary source text | contentText |
| Citation coverage | Summary is a WeSearch-generated derivative; primary citation is the original publisher URL. |
| Cluster | -uQ48jwyPHN1 |
| Cluster logic | Grouped by semantic title/content similarity across sources within a rolling window. Same-publisher template collisions are excluded from coverage comparison. |
| Ranking reason | Story pages are not engagement-ranked. Hub feeds use recency, with optional source-diversified chronological ordering (cap consecutive stories per source). No personalized ranking. |
| Publisher visit | Yes — open original |
| Substitutes article? | No — link-out required for full text |
Rights status (four layers)
WeSearch handling by dimension
| Indexing | May the item be indexed (stored, ranked, made findable)? | Allowed |
| Snippet | May a short excerpt of the publisher's text be shown? | Allowed |
| AI summary | May WeSearch generate its own short summary of the article? | Limited |
| Retrieval / RAG | May the content be exposed for third-party retrieval-augmented generation? | Not asserted |
| Model training | May the content be used to train AI models? | Not asserted |
| Commercial reuse | May the content be reused commercially? | Not permitted |
Basis: Derived from the published RSS/Atom feed. Contact: [email protected]. Reviewed: 2026-07-24.
Opening excerpt (first ~120 words) tap to expand
Our billing pipeline was suddenly slow. The culprit was a hidden bottleneck in ClickHouse2026-05-14James MorrisonChristian Endres9 min readThis post is also available in 日本語 and 한국어.At Cloudflare, we are heavy users of ClickHouse, an open source online analytical processing (OLAP) database. Every day, we make millions of calls to ClickHouse to determine how much users should be billed for their usage of Cloudflare products. If we don't finish those jobs in a timely fashion, the invoices become very difficult to reconcile.This pipeline powers hundreds of millions of dollars in usage revenue, fraud systems, and more, so being delayed has major downstream implications.Which is why it was a big problem when the daily aggregation jobs in ClickHouse – responsible for ensuring Cloudflare’s bills…
Excerpt limited to ~120 words for fair-use compliance. The full article is at Cloudflare Blog.
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