To provide better analysis of query execution time, it is important to measure time spent on each layer of the application. Many services provide "time spent on query" or similar metrics along with result. Blazegraph store used as a separate java process might introduce several points of performance degradation, including network communication, results serialization/deserialization, it might also produce some of the results very quickly, but consume more time to prepare complete result. The last case is the most important one, so additional header returned in the HTTP response will be very useful. This task created to track a suggested changeset to Blazegraph repo. If approved, the header X-FIRST-SOLUTION-MILLIS might be collected and sent to EventGate (see T101013)