ClickHouse

Prevent Duplicate Writes from Feature Flag Retries

This technical blog post recommends using a durable idempotency receipt to prevent duplicate writes when feature-flag retry traffic reaches rollout toggle endpoints. The author argues the backend that owns mutable state should bind a caller-generated idempotency key to a stable digest of the requested operation and commit the receipt in the same transaction as the state change. Retries should return the recorded result rather than reperforming the write; conflicting reuse of a key with different input must be rejected. The article covers failure boundaries (response loss, concurrent workers, changing flag evaluations), observability practices (track request_id, idempotency_key, decision, outcome, replay/conflict metrics), trade-offs for retention and analytical stores, and provides a compact Python/sqlite3 example illustrating the transactional receipt pattern. ClickHouse is mentioned as an analytical store candidate for immutable attempt and outcome events.

Integrating AI Agents with Self-Hosted SigNoz

An engineer describes building ArcNet to instrument and monitor an AI agent fleet using a self-hosted SigNoz instance. The write-up covers installation (SigNoz v0.133.0 via foundryctl), lessons about verifying emitted OpenTelemetry attributes (the Agno instrumentor emitted OpenInference conventions rather than gen_ai.*), turning guardrail results into structured span attributes for alerting, the need to use SigNoz's v5 alerts queries payload, using raw ClickHouse SQL panels as an escape hatch, and the distinction between telemetry (traces in SigNoz/ClickHouse) and replayable session transcripts (stored separately in SQLite). The author notes SigNoz MCP was unreliable in their setup and links code on GitHub.

IVP Seeks $1.8B Fund, Reports 31.1% Net IRR

Institutional Venture Partners (IVP) is raising $1.8 billion for its 19th flagship fund and tells prospective limited partners it has generated a 31.1% net internal rate of return since its 1980 founding. Fund documents reviewed by Newcomer show IVP is seeking premium economics — 2% management fee in year one, 2.25% thereafter, 25% carry stepping to 30% after a 2.5x hurdle, and a 3% GP commitment. The firm’s historical performance includes a 1996 fund that returned 6.7x net DPI (94.5% IRR); more recent vintages range from 1.2x net TVPI (2024) to 2.0x DPI (2015 vintage, 22.7% IRR). IVP highlights investments such as Perplexity, Baseten, ClickHouse, Chainguard, and Abridge, notes a major but not largest Anthropic stake, and appears to have missed OpenAI and SpaceX.