# Backbone services

- [Database](https://core.digit.org/guides/operations-guide/availability/backbone-services/database.md)
- [Kafka](https://core.digit.org/guides/operations-guide/availability/backbone-services/kafka.md)
- [Kafka Connect](https://core.digit.org/guides/operations-guide/availability/backbone-services/kafka-connect.md): Upgradation of Kafka Connect docker image to add additional connector
- [Elastic search](https://core.digit.org/guides/operations-guide/availability/backbone-services/elastic-search.md)
- [Elastic Search Rolling Upgrade](https://core.digit.org/guides/operations-guide/availability/backbone-services/elastic-search/elastic-search-rolling-upgrade.md)
- [ElasticSearch Direct Upgrade](https://core.digit.org/guides/operations-guide/availability/backbone-services/elastic-search/elasticsearch-direct-upgrade.md)