The blog post provides a detailed guide for upgrading an Elasticsearch 1.7 cluster hosted on Elasticsearch Service to a more current version, emphasizing the importance of updating due to new features, security patches, and performance improvements available in newer versions. Elasticsearch 1.7 reached its end of life 26 months prior, and the service will discontinue support for this version after April 8, 2019. The recommended upgrade path involves first moving to version 5.6.x, with a further upgrade to 6.x advised to avoid dealing with another end-of-life version soon. The post outlines the process of logging into the Elasticsearch Service console, creating a new deployment, and reindexing data, including handling breaking changes such as updates to string data types. For those unable to follow the suggested upgrade path, an alternative is to move data off the service and manage their own Elasticsearch cluster, though this is not recommended due to security concerns. The post also highlights the significant new functionalities added to the Elastic Stack since version 1.7 and encourages users to explore these innovations or participate in the 7.0 Elastic Pioneer Program.