Logstash i18n Filter Plugin

The i18n filter plugin in Logstash is used for internationalization and localization of log data. It allows you to translate field values based on predefined dictionaries, making it easier to standardize log messages across different languages or locales.

Syntax

filter {
  i18n {
    dictionary => [ "path/to/dictionary.yml" ]
    dictionary_path => "/path/to/dictionary/directory"
    field => "field_to_translate"
    destination => "translated_field"
    fallback => "default_value"
  }
}

For more detailed information, refer to the official Logstash i18n filter plugin documentation.

Example Use Case

Suppose you have log messages in multiple languages and want to standardize them to English for easier analysis. You can use the i18n filter to translate specific fields:

filter {
  i18n {
    dictionary => [ "/etc/logstash/dictionaries/error_messages.yml" ]
    field => "error_message"
    destination => "translated_error"
    fallback => "Unknown error"
  }
}

In this example, the plugin will translate the "error_message" field using the dictionary defined in "error_messages.yml" and store the result in the "translated_error" field. If no translation is found, it will use "Unknown error" as the fallback value.

Common Issues and Best Practices

1. Ensure that your dictionary files are properly formatted and contain all necessary translations.
2. Use the fallback option to handle cases where translations are not found.
3. Keep your dictionaries up to date as new log messages or error codes are introduced.
4. Consider using multiple dictionaries for different types of translations (e.g., error messages, status codes, etc.).
5. Monitor the performance impact of the i18n filter, especially when using large dictionaries or processing high volumes of logs.

Frequently Asked Questions

Q: Can I use multiple dictionaries with the i18n filter?
A: Yes, you can specify multiple dictionary files using the dictionary option or provide a directory path containing multiple dictionary files using the dictionary_path option.

Q: What file formats are supported for dictionaries?
A: The i18n filter supports YAML and JSON formats for dictionary files.

Q: How can I handle missing translations?
A: Use the fallback option to specify a default value when a translation is not found in the dictionary.

Q: Can I translate multiple fields in a single i18n filter?
A: No, you need to use separate i18n filter instances for each field you want to translate.

Q: Is it possible to dynamically load or update dictionaries without restarting Logstash?
A: Currently, the i18n filter does not support dynamic reloading of dictionaries. You need to restart Logstash to apply changes to dictionary files.