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Your SQS Queue Is Redelivering Messages Your Lambda Is Still Processing

Your order-processing Lambda starts sending duplicate confirmation emails. Not always — maybe one order in twenty. CloudWatch shows more invocations than messages published. The function code hasn't changed in weeks. What changed is that someone added a fraud check that pushed processing time from 25 seconds to around 45, and your SQS queue is still running the default 30-second visibility timeout. That combination is the whole bug. When a Lambda pulls a message from SQS, the message isn't deleted — it's hidden for the duration of the visibility timeout. If the function is still working when that window closes, SQS assumes the consumer died and hands the same message to another invocation. Now two Lambdas are processing the same order, both will "succeed," and both will send the email. Nothing errors. Nothing retries. There is no log line that says "this message was delivered twice because your timeouts are misconfigured." Infrawise ( npm ) flags this exact mismatch as a high-severity finding before it costs you an afternoon of staring at idempotency-free handler code. This post walks through why the bug is so hard to see, how the detection works, and how to keep an AI assistant from reintroducing it. Why you never catch this one yourself Three things make this misconfiguration nearly invisible: It passes every test. In local tests and staging, your handler processes a synthetic message in two seconds. The 30-second visibility window never comes close to expiring. The bug only exists under production conditions — real payload sizes, real downstream latency, cold starts stacking on top of slow dependencies. The defaults set the trap. SQS queues default to a 30-second visibility timeout. Lambda functions routinely get their timeout bumped to 60, 120, or 900 seconds as they grow. Nobody bumps the queue at the same time, because the two settings live in different consoles, different IaC resources, and usually different pull requests. The failure signature points elsewhe

2026-07-05 原文 →
AI 资讯

Modern C# Features: A Deep Dive into Records, Pattern Matching, Async, and Performance

Modern C# Features: A Deep Dive into Records, Pattern Matching, Async, and Performance A practical guide to the C# language features that have reshaped how we write .NET code — records, pattern matching, async/await improvements, nullable reference types, LINQ enhancements, Span<T> , and performance optimizations. Table of Contents Introduction Records Pattern Matching Async/Await Improvements Nullable Reference Types LINQ Enhancements Span<T> and Memory<T> Performance Optimizations Quick Reference Table Conclusion Introduction C# has evolved significantly since C# 8. Each release (9, 10, 11, 12, 13) has focused on three consistent themes: Conciseness — write less boilerplate to express the same intent. Safety — catch bugs at compile time instead of runtime (especially around null ). Performance — give developers low-level control without leaving the managed, safe world of .NET. This guide walks through the features that matter most in day-to-day development, with working code examples you can drop into a dotnet run project. 1. Records Introduced in C# 9 , record types give you immutable, value-based data models with almost no ceremony. Why records exist Before records, representing an immutable data object meant hand-writing a constructor, Equals , GetHashCode , ToString , and often a With -style copy method. Records generate all of this for you. // Before: a "plain" immutable class public class PersonClass { public string FirstName { get ; } public string LastName { get ; } public PersonClass ( string firstName , string lastName ) { FirstName = firstName ; LastName = lastName ; } public override bool Equals ( object ? obj ) => obj is PersonClass p && p . FirstName == FirstName && p . LastName == LastName ; public override int GetHashCode () => HashCode . Combine ( FirstName , LastName ); public override string ToString () => $"PersonClass {{ FirstName = { FirstName }, LastName = { LastName } }} " ; } // After: the same thing as a record public record Person ( stri

2026-07-05 原文 →
AI 资讯

Cron jobs and schedulers with BullMQ

In-process cron ( node-cron , @nestjs/schedule , OS crontab) runs inside one Node process. That is fine for a single instance, but it does not survive restarts gracefully, deduplicate across replicas, or share infrastructure with your other background jobs. BullMQ stores queues and schedulers in Redis . Job Schedulers (BullMQ 5.16+) are the recommended way to enqueue recurring work on a cron pattern or fixed interval. The same workers that process one-off jobs also process scheduled ones, with retries, backoff, and concurrency you already get from BullMQ. This post covers Job Schedulers in plain Node.js, operations and pitfalls, a NestJS setup with @nestjs/bullmq , and a runnable demo with a fast cron heartbeat and a daily cleanup cron. Prerequisites Node.js version 26 Redis at redis://localhost:6379 (included in the demo docker-compose.yml , or use Postgres and Redis containers with Docker Compose ) npm i bullmq For the NestJS section: npm i @nestjs/bullmq bullmq BullMQ 2.0+ does not require a separate QueueScheduler instance. Use the Job Scheduler API ( upsertJobScheduler ), not the deprecated repeat option on queue.add() . Mental model Piece Role Queue Holds jobs waiting to run Worker Executes jobs Job Scheduler Factory that enqueues jobs on a schedule Scheduled job A job instance produced by a scheduler A scheduler id is stable across deploys. Calling upsertJobScheduler with the same id updates the schedule in place instead of creating duplicates. Queue and worker Share one Redis connection config between the queue and the worker: import { Queue , Worker } from ' bullmq ' ; const connection = { host : ' localhost ' , port : 6379 }; const queue = new Queue ( ' reports ' , { connection }); const worker = new Worker ( ' reports ' , async ( job ) => { console . log ( `[ ${ job . name } ]` , new Date (). toISOString (), job . data ); }, { connection }, ); worker . on ( ' failed ' , ( job , error ) => { console . error ( job ?. name , error . message ); }); Start the

2026-07-05 原文 →
AI 资讯

Detecting Speaker Changes with Pyannote Segmentation 3.0 and ONNX Runtime

Hello, everyone. When listening to a conversation, we naturally keep track of who is speaking. A program has a harder job: beyond finding speech, it must also determine where one speaker gives way to another. Today, I will use an ONNX version of Pyannote Segmentation 3.0 to detect speaker changes in a two-person conversation and split the recording into one WAV file per utterance. What I Tested This lab uses FFmpeg to decode a roughly 14-second conversation into a 16 kHz mono waveform. It then combines the Pyannote segmentation model with simple post-processing to produce contiguous speaker segments. I wanted to verify: Whether six alternating utterances can be separated into six segments Whether the detected speaker indexes remain consistent throughout the recording Whether ONNX Runtime can process the audio faster than real time using only its CPU execution provider Whether every segment can be saved as a separate WAV file The complete code and reproducible environment are available in the pyannote-scd lab in kiarina/labs . This test performs segmentation using the model's speaker indexes. It does not compare speaker embeddings or run clustering, so it is not a complete speaker diarization pipeline that identifies the same person throughout a long recording. Reproducing the Lab You will need: mise uv FFmpeg curl The following commands fetch only this lab, download the shared test audio, and run it: git clone --depth 1 --filter = blob:none --sparse \ https://github.com/kiarina/labs.git cd labs git sparse-checkout set .gitignore .mise/tasks Makefile mise.toml \ 2026/07/04/pyannote-scd make download-test-assets mise -C 2026/07/04/pyannote-scd run On the first run, the task downloads the full-precision onnx/model.onnx file from onnx-community/pyannote-segmentation-3.0 on Hugging Face. uv then prepares the Python dependencies and runs the detector. How Speaker Segments Are Detected The input is this shared test asset: assets/mp3/conversation_2speaker_14s_16k.mp3 The re

2026-07-05 原文 →
AI 资讯

Building CogneeCode - AI Developer Memory Assistant

🧠 Building CogneeCode - AI Developer Memory Assistant The Problem Every developer faces the problem of lost context. "Why did I make this decision 3 months ago?" "How did I fix this bug last week?" Current AI tools forget everything between sessions. This is a real problem that wastes hours of developer time. My Solution CogneeCode is an AI developer memory assistant that builds a permanent knowledge graph using Cognee Cloud . It remembers every decision, bug fix, and code context you give it. What It Does ✅ Log architectural decisions with tags and context ✅ Log bug fixes with error messages and solutions ✅ Ask natural language questions about your codebase ✅ Get answers with evidence citations from the knowledge graph ✅ Semantic search across all memories ✅ Visual timeline of all decisions and bug fixes ✅ Analytics dashboard showing memory insights ✅ Knowledge graph visualization Tech Stack Backend: Flask (Python) Memory Layer: Cognee Cloud LLM: Groq Llama 3.3 Frontend: Vanilla HTML + CSS + JS Icons: Tabler Icons Cognee Cloud APIs Used remember() - Save decisions and bug fixes with metadata recall() - Natural language queries with evidence citations search() - Semantic search across memories visualize() - Knowledge graph visualization improve() - Memory graph enrichment forget() - Remove outdated memories Why This Matters When you return to a project after months, all your reasoning and solutions are still there, searchable in natural language. No more "Why did I do this?" or "How did I fix this bug?" Demo Watch the video: https://youtu.be/TNcBIBuPW7c Links 🔗 GitHub: https://github.com/JOSESAMUEL14/cogneecode 🔗 Live Demo: https://josesamuel.pythonanywhere.com AI Assistance Disclosure Built with assistance from Claude and Gemini AI. Built for WeMakeDevs x Cognee Hackathon 2026 Category: Best Use of Cognee Cloud ⭐ Star the repo if you find it useful!

2026-07-05 原文 →