Unusable metric: buffer available space ratio (fluentd_output_status_buffer_available_space_ratio)

[vinzent]

As a user I want to monitor the available buffer space and have alerts sent when free buffer space is being less than x %.

Prior to fluentd 1.10.0 the buffer available space ratio values could only be 0 (buffer is full) or 100 (no space used) due to a rounding issue. Fluentd fix PR: fluent/fluentd#2882 . Fix contained in fluentd >= 1.10.0 (git tag --contains fffc2cc71cc1d4b0d8bbd2d9817f0e875d032e9f on fluent/fluentd repo)

As the splunk connect for kubernetes uses fluentd 1.9.1 it is affected by the bug.

fluent-plugin-splunk-hec/docker/Gemfile

Line 6 in eef0c60

gem "fluentd", "=1.9.1"

[vinzent]

I can obeserve now other values than 0 and 100 with the fluentd_output_status_buffer_available_space_ratio metric. The upgrade to fluentd 1.11.5 in #166 fixed the issue.