Koharu Tech Notes

Aurora Serverless Adds 12 ACUs in One Second: What Still Needs Tuning

Aurora Serverless now adds 12 ACUs to its current capacity within one second on platform versions 3 and 4. The faster first step reduces ramp-up time, but capacity limits, buffer-cache behavior, and workload-specific monitoring still require deliberate choices.

Cloud Amazon Aurora

Cloud Security AWS Certificate Manager

Preparing for AWS ACM Email Validation Retirement: Migrate to DNS Without Changing the ARN

AWS Certificate Manager will end email validation for new public certificate requests on March 31, 2027 and renewals on September 30, 2027. Eligible certificates can migrate to DNS validation without changing their ARN, using a 72-hour validation window.

Why HA Does Not Make a Long PostgreSQL checkpoint_timeout Safe

A longer PostgreSQL checkpoint_timeout can increase WAL replay exposure not only on the primary but also when a standby restarts. This article explains why HA is not a substitute for recovery-time control and connects checkpoints, restartpoints, monitoring, and failure drills into one availability decision.

How Kiro’s Self-Organizing Multi-Agent Clusters Work Without a Central Orchestrator

kiro-flock is an AWS reference implementation in which Kiro CLI agents on EC2 coordinate through shared logs in S3 without a central orchestrator. This article explains when its ring, mesh, and swarm topologies fit—and what is lost when centralized verification is removed.

Cloud New technology

AWS Europe (London) renews its 2026 PASF accreditation: what the facility audit covers

AWS Europe (London) renewed its Police-Assured Secure Facilities (PASF) accreditation, which the Police Digital Service confirmed on May 28, 2026. The renewal continues assurance at the facility layer, while workload configuration and data handling still require each customer organization's assessment.

Cloud Security AWS

Designing Enterprise AI Trust in Three Layers: From OWNS and CALM to ORBIT

Published on August 9, 2026, the OWNS, CALM, and ORBIT model frames enterprise AI trust across strategy, platform readiness, and execution. This article connects those questions to the NIST AI RMF, transactional outbox, idempotency, and distributed tracing to show where a practical review can begin.

Cloud Enterprise AI

How PostgreSQL ignore_system_indexes Enables Recovery from Catalog Index Corruption

PostgreSQL's `ignore_system_indexes` setting removes damaged system catalog indexes from the read path so an operator can reach `REINDEX SYSTEM`. This article connects `-P`, single-user recovery, version differences, and post-repair verification.

When FIFO Is the Wrong Contract: Designing a Coalescing Event Queue in C++

In high-frequency state-update systems, preserving every event in FIFO order can delay the current value behind obsolete updates. This article explains key-based event coalescing through merge semantics, C++ concurrency, ordering, backpressure, and the event types that must remain complete.

Cpp Concurrency

Connect AWS DevOps Agent and ServiceNow over MCP for in-ticket incident investigations

AWS published a design connecting AWS DevOps Agent to ServiceNow MCP Server so investigations can correlate AWS telemetry with incidents, changes, and CMDB context. This article explains the two connection paths, permission boundaries, and guidance to reconcile before adoption.

Cloud AWS Devops Agent

2026-08-07

Running live speech-to-text with Foundry Local and C#

Microsoft's .NET Blog introduced a C# sample that uses Foundry Local to transcribe microphone audio in real time. The post shows how local AI in .NET can move beyond chat and into on-device speech recognition.

Dotnet New technology

2026-08-06

Why PostgreSQL COUNT(DISTINCT) cannot use parallel aggregation—and how to rewrite it

PostgreSQL cannot use parallel aggregation when an aggregate call contains DISTINCT. Using the primary source’s execution plans and benchmark as the starting point, this article explains a GROUP BY rewrite, NULL semantics, and what to validate with EXPLAIN.

2026-08-06

AWS Transform continuous modernization is now generally available

The AWS DevOps Blog announced on August 3, 2026 that AWS Transform continuous modernization is generally available in AWS Transform supported Regions. The practical change is that repository analysis, technical-debt findings, pull-request remediation, and recurring runs can be managed through the web app and CLI.

Cloud AWS

A small R function estimates a signpost location from city distances

The primary source introduces an R function that geocodes city names and estimates the current signpost location from distances to multiple cities. With the constraints of Nominatim, geosphere, and maps in view, the playful example becomes a useful geospatial data exercise.

R R Programming

SvelteKit 3 @next preview started in July 2026

The August 2026 Svelte Blog update centers on the first @next preview releases of SvelteKit 3. It highlights changes worth reviewing before a future migration, including shallow routing through `goto`, `$app/manifest`, `$app/service-worker`, and `refreshAll`.

Frontend New technology

Docker Joins NVIDIA Open Secure AI Alliance

Docker announced on July 30, 2026 that it has joined NVIDIA's Open Secure AI Alliance. The useful reading is that trust in AI agents is being framed around runtime, identity, governance, and security, not just the model itself.

Security Docker

Reading PostgreSQL platform trust through the CALM Platform Test

Vibhor Kumar wrote "The CALM Platform Test" to frame enterprise platform readiness through four dimensions: Changeability, Assurance, Leverage, and Measurability. Read with PostgreSQL logical replication, RLS, pgAudit, pgvector, and pg_stat_statements in mind, it becomes a practical prompt to verify changeability and evidence before placing AI workloads on a data platform.

std::rotate revisited: implementation notes for libc++ and libstdc++

ISO C++ Blog distributed Raymond Chen's article about `std::rotate` and swapping adjacent memory blocks at 2026-07-21T20:25:41Z. The excerpt revises an earlier explanation: only libc++ is described as using cycle decomposition for the random-access implementation, while libstdc++ uses a different algorithm.

Cpp Std Rotate

Reading the June 2026 AWS CIRT Threat Technique Catalog Update

AWS Security Blog published an article on June 29, 2026 about the June 2026 Threat Technique Catalog update, based on repeated incident response patterns seen by AWS CIRT. The provided source context does not include specific technique names or affected services, so this draft treats the post as a source to review against your own AWS environment.

Cloud Security AWS

Developer Tools Github Copilot

Grok 4.5 rolls out in GitHub Copilot with policy and billing checks

GitHub Changelog announced on July 28, 2026 that xAI Grok 4.5 is gradually rolling out in GitHub Copilot. The practical checks are plan and client availability, the default-off policy for Business and Enterprise, and usage-based billing.