V1 observations endpoint experiences 10x latency increase after v2 release

After ClickHouse backend migration and v2 API release (around Dec 22, 2025), the v1 observations endpoint (api/public/observations) experiences 10x higher latency, with median response times increasing from ~1.5s to ~15s. This affects observation fetching operations and can cause timeout exceptions in client libraries. The degradation was intentional to protect ClickHouse resources from expensive v1 API queries.

Migrate to the v2 observations endpoint (api/public/v2/observations) which is optimized for the new backend architecture and restores original performance. For Java SDK users, upgrade to langfuse-java client v0.1.2 or later which includes v2 route support. Update code from langfuse_client.api.observations.get_many() to use v2 equivalent. V1 endpoints are no longer prioritized for performance improvements.