mixin: Add fallback for MemAvailable (#2130)

Add a fallback to Buffers+Cached+MemFree+Slab for older Linux kernels where the MemAvailable metric is not available for memory utilization. Signed-off-by: Ben Kochie <superq@gmail.com>
2021-09-28 10:22:06 +02:00 · 2021-09-28 10:22:06 +02:00 · aeef1edd62
parent 0aec407666
commit aeef1edd62
1 changed files with 10 additions and 0 deletions
--- a/docs/node-mixin/rules/rules.libsonnet
+++ b/docs/node-mixin/rules/rules.libsonnet
@ -42,6 +42,16 @@
            expr: |||
              1 - (
                node_memory_MemAvailable_bytes{%(nodeExporterSelector)s}
+                or
+                (
+                  node_memory_Buffers_bytes{%(nodeExporterSelector)s}
+                  +
+                  node_memory_Cached_bytes{%(nodeExporterSelector)s}
+                  +
+                  node_memory_MemFree_bytes{%(nodeExporterSelector)s}
+                  +
+                  node_memory_Slab_bytes{%(nodeExporterSelector)s}
+                )
              /
                node_memory_MemTotal_bytes{%(nodeExporterSelector)s}
              )