# JVM warmup under load

> An Autoscaler added Java App Servers during a spike, and the new copies ran cold: 30% speed for their first 30 s.

## What happens

An Autoscaler added Java App Servers during a spike, and the new copies ran cold: 30% speed for their first 30 s.

## How to prevent it

Slow start on the Load Balancer, scheduled scaling, and a GraalVM native image, which starts warm. With slow start a new copy takes traffic gradually, so it never answers cold.

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

- [GraalVM native image](https://wiki.playquorum.dev/research/graal-native.md)
- [Autoscaling](https://wiki.playquorum.dev/research/autoscaling.md)

## Components it hits

[App Server](https://wiki.playquorum.dev/components/server.md)

## Facts

SEV3 JVM warmup under load
- **First Era:** [Seed](https://wiki.playquorum.dev/eras/seed.md)
- **Starts at:** SEV3
- **Escalates to:** SEVnull
- **Lasts:** 30 s

## See also

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

Source: https://wiki.playquorum.dev/incidents/jvm-warmup