Grafana Tempo 2.8 release: memory improvements, new TraceQL features, and more

Grafana Tempo 2.8 introduces significant memory improvements for compactors, reducing memory usage by over 50% in high-traffic environments. New TraceQL features include query hints for retrieving most recent results, parent span ID searches, sum_over_time metrics function, and topk/bottomk functions for better cardinality control. The release includes breaking changes such as removal of serverless features, default HTTP port change from 80 to 3200, and configuration parameter renaming. Future developments include RF1 rearchitecture rollout and LLM integration through a Tempo MCP server.