---
title: "Write Buffers"
url: https://develop.sentry.dev/backend/application-domains/write-buffers/
---

# Write Buffers

Sentry manages database row contention by buffering writes and flushing bulk changes to the database over a period of time. This is extremely helpful if you have high concurrency, especially if they’re frequently the same event.

For example, if you happen to receive 100,000 events/second, and 10% of those are reporting a connection issue to the database (where they’d get grouped together), enabling a buffer backend will change things so that each count update is actually put into a queue, and all updates are performed at the rate of how fast the queue can keep up.

## [Configuration](https://develop.sentry.dev/backend/application-domains/write-buffers.md#configuration)

To specify a backend, simply modify the `SENTRY_BUFFER` and `SENTRY_BUFFER_OPTIONS` values in your configuration:

```python
SENTRY_BUFFER = 'sentry.buffer.base.Buffer'
```

### [Redis](https://develop.sentry.dev/backend/application-domains/write-buffers.md#redis)

Configuring the Redis backend **requires the queue** or you won’t see any gains (in fact you’ll just negatively impact your performance).

Configuration is straight forward:

```python
SENTRY_BUFFER = 'sentry.buffer.redis.RedisBuffer'
```

By default, this will use the `default` named Redis cluster. To use a different cluster, provide the `cluster` option, as such:

```python
SENTRY_BUFFER_OPTIONS = {
    'cluster': 'buffer',
}
```