At a glance
- Did you know
- Browser tools let agents read and act on web pages, which is slow and brittle.
- Rule of thumb
- Use an API when one exists and keep the browser as the last resort.
- Watch out
- Seconds per page; bot blocks; memory per browser.
Its settings in ScaleMySystems
What you can change on it in the lab, and what each number does.
- Concurrency (slots)
- Calls it can work on at once (per instance when autoscaling). Needed slots ≈ calls per second × seconds each takes. Extra calls wait in the queue, then are rejected.
- Queue capacity
- Calls allowed to wait for a free slot. A bigger queue absorbs bursts but adds waiting time; 0 rejects straight away.
- vCPU
- CPU cores available. Needed ≈ calls per second × CPU per request ÷ 1000. Above about 90% busy it slows down and may crash.
- CPU per request (ms)
- CPU time each call burns. Part of what the component is; make the code cheaper to lower it.
- Latency (p50) (ms)
- Typical time one call takes here, before any calls it makes itself. Slots are held for this long.
- Latency (p99) (ms)
- The slowest 1% of calls. Callers must set their timeout above this or they cut off healthy calls.
- Timeout to dependencies (ms)
- How long it waits for each call it makes before giving up. Set it above the dependency’s p99 but low enough that a dead dependency does not hold every slot.
- Error rate
- Share of calls that fail on their own (bugs, declines, flaky tools). An agent that calls it on every step multiplies this.
- Quota (req/min)
- Calls allowed per minute (an API key or provider limit). Calls over it get 429s. Needed = calls per second × 60, with headroom.
Problems that start with it
- Browser automation bottleneck A web agent drives headless browsers: 16 browsers, about 2.5 s per action, 3 actions per task at 3 tasks a second.
- Research agents share few browsers A deep-research system fans out to 5 subagents that each browse the web; the browser pool has 16 browsers.
- A new browser for every page Research agents read about 8 web pages per task, 30 tasks a minute. The hosted-browser plan allows 100 sessions at once but only 50 new sessions a minute, and the browser tool opens a fresh session for every page.
- Deep research: from launch build to real traffic A multi-agent research product on its first servers: the lead agent fans each question out to sub-agents that search and browse the web, and the browser tool, sub-agent pool and model capacity are an eighth of their real size. Questions arrive one a second and each takes minutes. One in ten fails.
Full lesson coming soon
Lessons are being added one component at a time: how it works, its settings, a live exercise to break and fix it, interview questions and a short check. See the Circuit breaker lesson for what one looks like.