12. Performance & Limits

Part 12

/admin/system/performance · Platform scope. Runtime tuning for the services behind QuantaCloud. Most installations never need to touch it.

Performance & Limits. Change one value at a time and note what you changed.

12.1. Database

The page opens read-only; press Edit to change a value. Under Database, a table gives connection-pool sizing per service — Service, Pool size, Replicas, Subtotal and Source. The subtotal is what that service will actually open; the source column tells you whether the value is a default or something someone set. Raising pool sizes without raising the database’s own connection limit causes failures rather than speed.

12.2. Retention

How long various records are kept before they are swept away. These decide how far back Session History can look, and how much housekeeping data accumulates:

Audit log retention

How long audit-log rows are kept. The default keeps a full year plus a grace margin.

API activity log retention

How long API activity rows are kept — this is what Session History reads.

Terminal jobs retention

How long finished background-job rows are kept.

GC queue retention

How long terminal garbage-collection rows are kept.

12.3. Workers and sweeps

How often background work runs: the retention sweep, the garbage-collection sweep, the lease-expiry sweep, and the batch size a worker claims per pass. Longer intervals mean less load and slower cleanup.

12.4. Resilience

The database circuit breaker: the rolling window over which the failure rate is measured, the minimum samples before it may open (so one early failure cannot trip it), the failure rate at which it opens, and the trial timeout for a half-open trial. Defaults are chosen to avoid false trips; change them only with evidence.

Change one thing at a time

These values interact. Record what you changed and when, change one at a time, and give each change long enough to show its effect before making another.