# Latency regression

> A deploy put one more synchronous call on every request: each answer is 150 ms slower.

## What happens

A deploy put one more synchronous call on every request: each answer is 150 ms slower.

## How to prevent it

Percentiles and tracing on the request path, and a canary that watches p99.

The postmortem opens the first of these that you do not own yet:

- [Percentiles](https://wiki.playquorum.dev/research/percentiles.md)
- [Distributed tracing](https://wiki.playquorum.dev/research/tracing.md)

## Facts

SEV3 Latency regression
- **First Era:** [Series A](https://wiki.playquorum.dev/eras/series-a.md)
- **Starts at:** SEV3
- **Escalates to:** SEV2
- **Lasts:** 1 min

## See also

- [Incidents](https://wiki.playquorum.dev/incidents.md)

Source: https://wiki.playquorum.dev/incidents/latency-regression