From 8a3b30ca2b2afd389440889f2bfcb36b00cc88f6 Mon Sep 17 00:00:00 2001
From: Iustin Pop <iustin@google.com>
Date: Wed, 21 Jul 2010 17:33:00 +0200
Subject: [PATCH] Introduce per-metric weights
Currently all metrics have the same weight (we just sum them together).
However, for the hard constraints (N+1 failures, offline nodes, etc.)
we should handle the metrics differently based on their meaning. For
example, an instance living on a primary offline node is worse than an
instance having its secondary node offline, which in turn is worse than
an instance having its secondary node failing N+1.
To express this case in our code, we introduce a table of weights for
the metrics, with which we can influence their relative importance.
---
Ganeti/HTools/Cluster.hs | 42 ++++++++++++++++++++++------------------
1 file changed, 23 insertions(+), 19 deletions(-)
diff --git a/Ganeti/HTools/Cluster.hs b/Ganeti/HTools/Cluster.hs
index d8c90665e..ab573645f 100644
--- a/Ganeti/HTools/Cluster.hs
+++ b/Ganeti/HTools/Cluster.hs
@@ -202,21 +202,24 @@ computeAllocationDelta cini cfin =
runa = RSpec un_cpu (truncate t_mem - f_imem) (truncate t_dsk - f_idsk)
in (rini, rfin, runa)
--- | The names of the individual elements in the CV list
-detailedCVNames :: [String]
-detailedCVNames = [ "free_mem_cv"
- , "free_disk_cv"
- , "n1_cnt"
- , "reserved_mem_cv"
- , "offline_all_cnt"
- , "offline_pri_cnt"
- , "vcpu_ratio_cv"
- , "cpu_load_cv"
- , "mem_load_cv"
- , "disk_load_cv"
- , "net_load_cv"
- , "pri_tags_score"
- ]
+-- | The names and weights of the individual elements in the CV list
+detailedCVInfo :: [(Double, String)]
+detailedCVInfo = [ (1, "free_mem_cv")
+ , (1, "free_disk_cv")
+ , (1, "n1_cnt")
+ , (1, "reserved_mem_cv")
+ , (4, "offline_all_cnt")
+ , (16, "offline_pri_cnt")
+ , (1, "vcpu_ratio_cv")
+ , (1, "cpu_load_cv")
+ , (1, "mem_load_cv")
+ , (1, "disk_load_cv")
+ , (1, "net_load_cv")
+ , (1, "pri_tags_score")
+ ]
+
+detailedCVWeights :: [Double]
+detailedCVWeights = map fst detailedCVInfo
-- | Compute the mem and disk covariance.
compDetailedCV :: Node.List -> [Double]
@@ -265,7 +268,7 @@ compDetailedCV nl =
-- | Compute the /total/ variance.
compCV :: Node.List -> Double
-compCV = sum . compDetailedCV
+compCV = sum . zipWith (*) detailedCVWeights . compDetailedCV
-- | Compute online nodes from a Node.List
getOnline :: Node.List -> [Node.Node]
@@ -797,9 +800,10 @@ printInsts nl il =
printStats :: Node.List -> String
printStats nl =
let dcvs = compDetailedCV nl
- hd = zip (detailedCVNames ++ repeat "unknown") dcvs
- formatted = map (\(header, val) ->
- printf "%s=%.8f" header val::String) hd
+ (weights, names) = unzip detailedCVInfo
+ hd = zip3 (weights ++ repeat 1) (names ++ repeat "unknown") dcvs
+ formatted = map (\(w, header, val) ->
+ printf "%s=%.8f(x%.2f)" header val w::String) hd
in intercalate ", " formatted
-- | Convert a placement into a list of OpCodes (basically a job).
--
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