Elasticsearch is the most popular solution for self-hosted log aggregation. This is the "E" in the (former) ELK Stack. It features a great search engine based on Apache Lucene.
As the de facto standard in its niche, Elasticsearch has a lot of integrations and has great support both from the community and as a commercial service. Some cloud providers offer Elasticsearch as a managed service, which makes it easier to introduce Elasticsearch in your application. Other than that, Elastic, the company that makes Elasticsearch, offers a hosted solution that is not tied to any particular cloud provider.
