Chapter 4. Loki query performance

Procedure

1. In the OpenShift Container Platform web console, navigate to the Metrics Observe tab.

2. Note the following values:

   • duration: Denotes the amount of time a query took to run.
   • queue_time: Denotes the time a query spent in the queue before being processed.
   • chunk_refs_fetch_time: Denotes the amount of time spent in getting chunk information from the index.
   • store_chunks_download_time: Denotes the amount of time in getting chunks from cache or storage.

3. Calculate the following performance metrics:

   • total query time as total_duration:

     total_duration = duration + queue_time

   • Percentage of the total duration that a query spent in the queue as Queue Time:

     Queue Time = queue_time / total_duration * 100

   • Calculate the percentage of the total duration that was spent in getting chunk information from the index as Chunk Refs Fetch Time:

     Chunk Refs Fetch Time = chunk_refs_fetch_time / total_duration * 100

   • Calculate the percentage of the total duration that was spent in getting chunks from cache or storage:

     Chunks Download Time = store_chunks_download_time / total_duration * 100

   • Calculate the percentage of the total duration that was spent in executing the query:

     Execution Time = (duration - chunk_refs_fetch_time - store_chunks_download_time) / total_duration * 100

4. Refer to Query performance analysis to understand the reason for each metric and how each metric affects query performance.