---
layout: docs
page_title: Resource Quotas
description: Providing measures against misbehaving applications and users overdrawing resources in Vault.
---

# Resource quotas

Every single interaction with Vault, whether to put secrets into the key/value
store or to generate new pairs of database credentials for the MySQL database,
needs to go through Vault’s API.

One side effect of the API driven model is that applications and users can
misbehave by overwhelming system resources through consistent and high volume API
requests resulting in denial-of-service issues in some Vault nodes or even the
entire Vault cluster. This risk is significantly increased when Vault API endpoints
are exposed to thousands or millions of services deployed across a global infrastructure,
especially in use cases of Vault where Vault is deployed as a service for internal
developers.

Vault provides a feature, resource quotas, that allows Vault operators to specify
limits on resources used in Vault. Specifically, Vault allows operators to create
and configure API rate limits. Users of Vault Enterprise have a second option, alongside
rate limits, [lease-count quotas](/vault/docs/enterprise/lease-count-quotas), which can
limit the number of leases that can be in use at one time.

## Rate limit quotas

Vault allows operators to create rate limit quotas which enforce API rate
limiting using a [token bucket](https://en.wikipedia.org/wiki/Token_bucket) algorithm.
A rate limit quota can be created at the root level or defined on a namespace,
mount, or full API path by specifying a `path` when creating the quota. The rate
limiter is applied to each unique client IP address on a per-node basis (i.e. rate limit
quotas are not replicated). A client may invoke `rate` requests at any given second,
after which they may invoke additional requests at `rate` per-second.

A rate limit quota defined at the root level (i.e. empty `path`) is inherited by
all namespaces and mounts. It acts as a single rate limiter for the entire Vault
API. A rate limit quota defined on a namespace takes precedence over the global
rate limit quota, a rate limit quota defined for a mount takes precedence over
the global and namespace rate limit quotas, and a rate limit quota defined for
a specific path will take precedence over global, namespace, and mount quotas.
Additionally, quotas defined with a `role` to limit login requests made using
that role on the specified auth mount will take precedence over all other quotas.
In other words, the most specific quota rule will be applied.

A rate limit can be created with an optional `block_interval`, such that when set
to a non-zero value, any client that hits a rate limit threshold will be blocked
from all subsequent requests for a duration of `block_interval` seconds.

Vault also allows the inspection of the state of rate limiting in a Vault node
through various [metrics](/vault/docs/internals/telemetry/metrics/core-system#quota-metrics) exposed
and through enabling optional audit logging.

## Exempt routes

By default, the following paths are exempt from rate limiting. However, Vault
operators can override the set of paths that are exempt from all rate limit
resource quotas by updating the `rate_limit_exempt_paths` configuration field.

- `sys/generate-recovery-token/attempt`
- `sys/generate-recovery-token/update`
- `sys/generate-root/attempt`
- `sys/generate-root/update`
- `sys/health`
- `sys/seal-status`
- `sys/unseal`

## Replication

When creating or modifying a quota on a performance secondary cluster, the path
referred to by the quota must exist on the secondary cluster. Vault will error if
you attempt to create or update a quota for a path that doesn't exist.

Quotas are stored on the primary cluster and all requests to create, update, or
delete quotas get forwarded to the primary cluster. This has several implications:

1. It is not possible to create a quota for local mount on a performance secondary
cluster.
1. Quotas can be read on a performance secondary cluster, even when the path
referred to by the quota is local to the primary cluster.
1. If you create a performance primary and performance secondary cluster and
set up a local mount on both clusters with the same path, a user that only has
access to the performance secondary cluster can create/update a quota for this
path that will apply to the performance primary cluster.

## Tutorial

Refer to [Protecting Vault with Resource
Quotas](/vault/tutorials/operations/resource-quotas) for a
step-by-step tutorial.

## API

Resource quotas can be managed over the HTTP API. Please see
[Rate Limit Quotas API](/vault/api-docs/system/rate-limit-quotas),
[Lease Count Quotas API](/vault/api-docs/system/lease-count-quotas), and [Quotas
Config API](/vault/api-docs/system/quotas-config) for more details.
