Controller Node Cache - Performance Statistics: report template

This template produces historical performance reports for controller node caches.

Summary

  • Report template name: Controller Node Cache - Performance Statistics

  • Default report name: Controller Node Cache Performance

  • Default charts (metrics): Hit percentage, delay ack

  • Other charts (metrics): Access count, Locked blocks, Page states, Dirty pages, Max dirty pages

Key default settings

  • Report type: Time interval

  • Sampling: Hourly

  • Report duration (period): 1 week

  • Objects: All objects

Key metric terms and descriptions

  • Clean: Number of clean cache pages (valid data on page).

  • FC 10K, FC 15K: Fibre Channel drives, speed 10K, 15K.

  • Free: Free space for the cache.

  • Lock blk/s: Number of locked blocks.

  • NL: Nearline drive.

  • Read hits/s: Number of reads that hit in the node cache.

  • Read miss/s: Number of reads that miss in the node cache.

  • Reads/s: Percentage of reads (out of total reads) that hit in the cache.

  • Recov: During node down, the number of dead node pages that were recovered and must be written to disk.

  • SSD 100K, SSD 150K: Solid-state drives, speed 100K, 150K.

  • Write1: Number of dirty pages that have been modified exactly 1 time. A page is dirty when it has been modified in cache but has not been written to physical drives.

  • WriteN: Number of dirty pages that have been modified more than 1 time.

  • Write hits/s: Number of writes for which the page is already in cache and is dirty. Dirty refers to previously written data that has not been flushed to physical drives.

  • Writes/s: Percentage of writes (out of total writes) that hit in the cache.

  • Write miss/s: Number of writes that miss in the cache. A write is considered a miss if the page is not in the cache or if the page is not dirty in the cache. Dirty refers to previously written data that has not been flushed to physical drives.

  • Write scheduled: Number of pages scheduled to be written to physical drives.

  • Writing: Number of pages currently being written by the flusher to physical drives.