[LUDOC-388] Minor corrections to collection of client statistics in section 35.3

Thu, 10 Aug 2017 15:49:27 +0000

In sections 35.3.3 and 35.3.4, the process to activate collection of the offset_stats, extents_stats, and extents_stats_per_process statistics is said to be

The collection of statistics in all three of these files is activated by writing anything into any one of the files.

In reality, you need to write anything other than ‘0’ or ‘disable’ into any of these files to enable collection of statistics because ‘0’ or ‘disable’ will stops collection of these statistics to the file.

Also, in section 35.3.4.1. Client-Based I/O Extent Size Survey, “extent_stats” is missing an “s” in the following

The extent_stats histogram in the llite directory shows the statistics for the sizes of the read/write I/O extents. This file does not maintain the per-process statistics.

In the same section, we have

The file can be cleared by issuing the following command:
# lctl set_param llite.testfs-*.extents_stats=0

Although this is true, setting the extents_stats to zero also disables collection of the statistics. I think we probably want “=1” here because setting extents_stats to 1 will reset the stats and will not disable collection of them.

I will upload a patch

Whamcloud Community JIRA

[LUDOC-388] Minor corrections to collection of client statistics in section 35.3