Merge pull request #4279 from vespa-engine/toregge/handle-no-directio…

…-padding-in-stats

Handle no directio padding in stats for cached disk io.

tests/search/metrics/metrics.rb

@@ -199,7 +199,7 @@ def assert_document_db_cached_disk_io(metrics, expect_cached)
     posting_list_cache_hit_rate = get_postinglist_cache_hit_rate(metrics)
     puts "posting_list_cache_hit_rate = " + posting_list_cache_hit_rate.to_s
     if expect_cached
-      assert(1000 < f1_cached_disk_io["sum"])
+      assert(10 < f1_cached_disk_io["sum"])
       assert(0 < f1_cached_disk_io["count"])
       assert(0 < posting_list_cache_hit_rate)
     else