<!-- Source: https://docs.squirro.com/en/latest/technical/admin/configuration/index.html -->
# Configuration

A Squirro cluster can be extensively configured. This section covers the available configuration options and facilities in detail.

## Configuration Files

Each service has its own configuration file in addition to the common configuration file that applies to all services.

Individual services include:

- [common.ini](config-files/config-ini.md#admin-config-ini)
- [configuration.ini](config-files/config-ini.md#admin-config-ini)
- [convert.ini](config-files/convert-ini.md#admin-convert-ini)
- [datasource.ini](config-files/datasource-ini.md#admin-datasource-ini)
- [digestmailer.ini](config-files/digestmailer-ini.md#admin-digestmailer-ini)
- [emailsender.ini](config-files/emailsender-ini.md#admin-emailsender-ini)
- [filtering.ini](config-files/filtering-ini.md#admin-filtering-ini)
- [frontend.ini](config-files/frontend-ini.md#admin-frontend-ini)
- [ingester.ini](config-files/ingester-ini.md#admin-ingester-ini)
- [topic.ini](config-files/topic-ini.md#admin-topic-ini)

## Configuration Service

Squirro’s Configuration Service is the centralized repository for server, project, and user configuration. To learn more, see [Configuration Service](config-service.md#admin-config-service).

## File Upload Limits

Squirro enforces file upload size limits that must be configured at both the application and nginx levels. For instructions on configuring and modifying these limits, see [File Upload Size Limits](file-upload-limits.md#admin-file-upload-limits).

## Configuration Interpolation

Configuration interpolation allows you to retrieve values from the Configuration Service and inject them into different parts of the Squirro platform. See [Configuration Interpolation](config-interpolation.md#admin-config-interpolation) for more details.

## Configuration Key Naming Conventions

All configuration keys in Squirro must follow specific naming conventions to ensure consistency and prevent validation errors. These rules define the allowed characters and structure for configuration keys, including secret keys used for sensitive data like API passwords. See [Configuration Key Naming Conventions](key-naming-conventions.md#configuration-key-naming-conventions) for detailed formatting rules and examples.

## Securing Configuration Files

For information on securing configuration files, including encryption, see [Securing Configuration Files](securing-config-files.md#admin-securing-config-files).

## Securing Redis Instance Over SSL

SSL communication can be established between Redis instances and Squirro services. To learn more, see [Securing Redis Instance over SSL](securing-redis.md#admin-securing-redis).

## Secure Configuration Guide

You can take additional steps to secure Squirro using out-of-the-box features, as outlined in the [Secure Configuration Guide](secure-config-guide.md#admin-secure-config-guide).

## SSL Certificates

For information on obtaining Squirro SSL certificates, see [SSL Certificates](ssl-certificates.md#admin-ssl).

## Changing the Default Language

Squirro has additional language capabilities available out of the box. For instructions on setting German, French, or Italian as the default project language, see [Changing the Default Language](default-language.md#admin-default-language).

## Project Translations

You can define a custom dictionary of translated text for a project, so that dashboard elements such as widget titles and labels appear in the language selected by the user. For instructions on creating and using project translations, see the [Translating Dashboards with Project Translations](project-translations.md#admin-project-translations) page.

## Email Templates

Squirro has a variety of email templates available for alerts, password resets, and so on. See [Email Templates](email-templates.md#admin-email-templates) for more information.

## Enable Proxy Server for Outgoing Calls

To enable a proxy server for outgoing calls, see [Enable Proxy Server for Outgoing Calls](enable-proxy.md#admin-enable-proxy).

## PDF Viewer

Starting with Squirro 3.15.4, the built-in PDF viewer requires a license key. For instructions on obtaining and applying the license key, see the [PDF Viewer](pdf-viewer.md#pdf-viewer-introduction) page.

## Elasticsearch

For Elasticsearch configuration, refer to its official documentation: [Elasticsearch Configuration](https://www.elastic.co/guide/en/elasticsearch/reference/master/system-config.html).