﻿---
title: Manage data quality
description: After selecting a stream, use the Data quality tab to find failed and degraded documents in your stream. Use the following components to monitor the health...
url: https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/4485/solutions/observability/streams/management/data-quality
---

# Manage data quality
After selecting a stream, use the **Data quality** tab to find failed and degraded documents in your stream. Use the following components to monitor the health of your data and identify and fix issues:
- **Degraded documents:** Documents with the `ignored` property usually because of malformed fields or exceeding the limit of total fields when `ignore_above:false`. This component shows the total number of degraded documents, the percentage, and status (**Good**, **Degraded**, **Poor**).
- **Failed documents:**: Documents that were rejected during ingestion because of mapping conflicts or pipeline failures.
- **Quality score:** Streams calculates the overall quality score (**Good**, **Degraded**, **Poor**) based on the percentage of degraded and failed documents.
- **Trends over time:** A time-series chart so you can track how degraded and failed documents are accumulating over time. Use the date picker to zoom into a specific range and understand when problems are spiking.
- **Issues:** `stack: preview 9.2`Find issues with specific fields, how often they've occurred, and when they've occurred.


## Failure store

A [failure store](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/4485/manage-data/data-store/data-streams/failure-store) is a secondary set of indices inside a data stream, dedicated to storing failed documents. Instead of losing documents that are rejected during ingestion, a failure store retains it in a `::failures` index, so you can review failed documents to understand what went wrong and how to fix it.

### Required permissions

To view and modify failure store in Elastic Stack, you need the following data stream level privileges:
- `read_failure_store`
- `manage_failure_store`

For more information, refer to [Granting privileges for data streams and aliases](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/4485/deploy-manage/users-roles/cluster-or-deployment-auth/granting-privileges-for-data-streams-aliases).

### Turn on failure stores

In Streams, you need to turn on failure stores to get failed documents. To do this, select **Enable failure store** in the **Failed documents** component. From here you can set your failure store retention period.
For more information on data quality, refer to the [data set quality](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/4485/solutions/observability/data-set-quality-monitoring) documentation.