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Database Connection Pooling Lab

Watch requests borrow, queue, time out, and return a small set of database sessions under real pressure.

Load shapeTune the same burst before stepping through the pool lifecycle
live sessions
4
running now
4
waiting
3
timed out
0
hold time
60 ms
capacity hint
66.7 req/s
Pool inventoryWarm idle sessions absorb the first burst
slot 1
busy
running tx
slot 2
busy
running tx
slot 3
opening
auth + setup
slot 4
opening
auth + setup
Request burstBorrowers waiting at the pool boundary
req 1 · running
req 2 · running
req 3 · running
req 4 · running
req 5 · queued
req 6 · queued
req 7 · queued

acquire timeout 250 ms · queue wait estimate 60 ms · min idle target 2

Step 1 / 6Warm idle sessions absorb the first burst

A pool keeps a few authenticated connections ready, so the next request can start SQL immediately instead of paying login and backend setup first.

Pools exist because a database session is expensive state, not because opening sockets looks untidy in traces.

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