[{"data":1,"prerenderedAt":81},["ShallowReactive",2],{"api:\u002Fapi\u002Fconfig:en":3,"api:\u002Fapi\u002Fnotes:en":8,"api:\u002Fapi\u002Fprojects\u002Fjob-queue:en":32},{"email":4,"lang":5,"name":6,"role":7},"hello@ewsirdev.example","en","Ewsirdev","Web developer: websites, landing pages and Go services",[9,16,22,27],{"slug":10,"lang":5,"title":11,"date":12,"summary":13,"project":14,"minutes":15},"double-booking","Double booking: a transaction plus a partial UNIQUE index","2026-10-20","How booking-slots protects against two clients booking the same time at once, and how that protection is tested.","booking-slots",1,{"slug":17,"lang":5,"title":18,"date":12,"summary":19,"project":20,"minutes":21},"lease-and-fencing","Lease and fencing: how a queue neither loses a job nor lets a zombie finish it twice","A worker can crash, stall, or wake up after its job was taken by someone else. How the lease and the lease token in job-queue deal with that on SQLite.","job-queue",2,{"slug":23,"lang":5,"title":24,"date":12,"summary":25,"project":26,"minutes":21},"p95-nearest-rank","p95 in an uptime monitor: the nearest-rank method and what it does not hide","How uptime-monitor computes p50\u002Fp95 latency and uptime, why the nearest-rank method was chosen, and where those numbers can mislead.","uptime-monitor",{"slug":28,"lang":5,"title":29,"date":12,"summary":30,"project":31,"minutes":21},"websocket-from-scratch","WebSocket on the standard library: what really happens under new WebSocket()","Why realtime-rooms has its own RFC 6455 layer, which protocol violations it checks, and why a library is still the better choice for production.","realtime-rooms",{"slug":20,"title":33,"type":34,"stack":35,"description":42,"highlights":43,"run":48,"hue":49,"og":50,"shots":51,"case":59,"case_lang":5,"prev":77,"next":79},"Conveyor: job queue","backend",[36,37,38,39,40,41],"Go","SQLite","REST API","SSE","Prometheus","Docker","A background job queue: priorities, delayed and cron jobs, retries with backoff and jitter, dead-letter, idempotency keys, leases with fencing, Prometheus metrics.",[44,45,46,47],"At-least-once with lease and fencing","Retries with backoff and jitter + dead-letter","Custom cron parser","Prometheus metrics and graceful shutdown","cd job-queue && set API_TOKEN=demo&& set SEED_DEMO=1&& go run .\u002Fcmd\u002Fserver",249,"\u002Fog\u002Fen\u002Fjob-queue.jpg",{"desktop":52,"desktop_sm":53,"mobile":54,"dw":55,"dh":56,"mw":57,"mh":58},"\u002Fshots\u002Fjob-queue-desktop.webp","\u002Fshots\u002Fjob-queue-desktop-sm.webp","\u002Fshots\u002Fjob-queue-mobile.webp",1280,800,390,844,{"about":60,"features":63,"run":70,"notes":74},[61,62],"Conveyor is a background job queue: persistent in SQLite, with a worker pool, priorities, delayed and cron jobs, retries with exponential backoff and jitter, and a dead-letter queue with manual retry.","It guarantees at-least-once delivery: a job is held under a lease with a heartbeat, and the lease token (fencing) stops a zombie worker from corrupting the result. It also has Prometheus metrics and a live SSE dashboard.",[64,65,66,67,68,69],"Priorities 0-9, delayed start, and a custom cron expression parser (lists, ranges, steps, @daily and so on)","Idempotency keys: enqueueing again returns the existing job, even when two requests race","Atomic job claiming with a single UPDATE ... RETURNING, so no double execution even from two processes","Lease and reaper for crashed workers; graceful shutdown returns unfinished jobs to the queue","REST API, \u002Fmetrics in Prometheus format, a dashboard","Tests with -race for concurrent claiming, lease, backoff, cron and shutdown; Docker",[71,72,73],"git clone \u003Crepository on request> job-queue","cd job-queue","API_TOKEN=demo SEED_DEMO=1 go run .\u002Fcmd\u002Fserver   # http:\u002F\u002Flocalhost:8085",[75,76],"The demo handlers (email.send, image.resize, webhook.call) only simulate work: nothing is sent.","A single SQLite file, so it scales only within one machine. At-least-once only, so handlers must be idempotent; there are no job chains and no per-queue rate limits. Metric counters reset on restart.",{"slug":26,"title":78},"Pulse: uptime monitor",{"slug":31,"title":80},"Rooms: realtime chat and board",1792697892726]