From e8695dc6f346b4431ea4bfa47f26c11c134f439b Mon Sep 17 00:00:00 2001
From: Hector Sanjuan <code@hector.link>
Date: Thu, 23 Jun 2022 11:47:11 +0200
Subject: [PATCH 1/3] informer/disk: set repoSize weight to negative

smaller repositories should have more priority
---
 informer/disk/disk.go | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/informer/disk/disk.go b/informer/disk/disk.go
index 17012809..e50e5b45 100644
--- a/informer/disk/disk.go
+++ b/informer/disk/disk.go
@@ -105,7 +105,8 @@ func (disk *Informer) GetMetrics(ctx context.Context) []api.Metric {
 	}
 
 	var repoStat api.IPFSRepoStat
-	var metric uint64
+	var weight uint64
+	var value string
 
 	valid := true
 
@@ -126,24 +127,27 @@ func (disk *Informer) GetMetrics(ctx context.Context) []api.Metric {
 			size := repoStat.RepoSize
 			total := repoStat.StorageMax
 			if size < total {
-				metric = total - size
+				weight = total - size
 			} else {
 				// Make sure we don't underflow and stop
 				// sending this metric when space is exhausted.
-				metric = 0
+				weight = 0
 				valid = false
 				logger.Warn("reported freespace is 0")
 			}
+			value = fmt.Sprintf("%d", weight)
 		case MetricRepoSize:
-			metric = repoStat.RepoSize
+			// smaller repositories have more priority
+			weight = -repoStat.RepoSize
+			value = fmt.Sprintf("%d", repoStat.RepoSize)
 		}
 	}
 
 	m := api.Metric{
 		Name:          disk.Name(),
-		Value:         fmt.Sprintf("%d", metric),
+		Value:         value,
 		Valid:         valid,
-		Weight:        int64(metric),
+		Weight:        int64(weight),
 		Partitionable: false,
 	}
 

From 2aec92301dfb4a8fce309e3d3233d7f57054cf8f Mon Sep 17 00:00:00 2001
From: Hector Sanjuan <code@hector.link>
Date: Thu, 23 Jun 2022 11:58:07 +0200
Subject: [PATCH 2/3] metrics: set block/added_size unit to bytes

---
 observations/metrics.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/observations/metrics.go b/observations/metrics.go
index 48d7dd0f..59667b07 100644
--- a/observations/metrics.go
+++ b/observations/metrics.go
@@ -44,7 +44,7 @@ var (
 	PinsPinAdd      = stats.Int64("pins/pin_add", "Total number of IPFS pin requests", stats.UnitDimensionless)
 	PinsPinAddError = stats.Int64("pins/pin_add_errors", "Total number of failed pin requests", stats.UnitDimensionless)
 	BlocksPut       = stats.Int64("blocks/put", "Total number of blocks/put requests", stats.UnitDimensionless)
-	BlocksAddedSize = stats.Int64("blocks/added_size", "Total size of blocks added in bytes", stats.UnitDimensionless)
+	BlocksAddedSize = stats.Int64("blocks/added_size", "Total size of blocks added in bytes", stats.UnitBytes)
 
 	BlocksAdded      = stats.Int64("blocks/added", "Total number of blocks added", stats.UnitDimensionless)
 	BlocksAddedError = stats.Int64("blocks/put_errors", "Total number of block/put errors", stats.UnitDimensionless)

From c4547698878583e6e166deb4652cc6a48598af45 Mon Sep 17 00:00:00 2001
From: Hector Sanjuan <code@hector.link>
Date: Thu, 23 Jun 2022 11:58:35 +0200
Subject: [PATCH 3/3] Informer/disk: record issued metric weights as prometheus
 metric.

---
 informer/disk/disk.go   | 5 +++++
 observations/metrics.go | 8 ++++++++
 2 files changed, 13 insertions(+)

diff --git a/informer/disk/disk.go b/informer/disk/disk.go
index e50e5b45..cd941a4c 100644
--- a/informer/disk/disk.go
+++ b/informer/disk/disk.go
@@ -8,10 +8,12 @@ import (
 	"sync"
 
 	"github.com/ipfs-cluster/ipfs-cluster/api"
+	"github.com/ipfs-cluster/ipfs-cluster/observations"
 
 	logging "github.com/ipfs/go-log/v2"
 	rpc "github.com/libp2p/go-libp2p-gorpc"
 
+	"go.opencensus.io/stats"
 	"go.opencensus.io/trace"
 )
 
@@ -152,5 +154,8 @@ func (disk *Informer) GetMetrics(ctx context.Context) []api.Metric {
 	}
 
 	m.SetTTL(disk.config.MetricTTL)
+
+	stats.Record(ctx, observations.InformerDisk.M(m.Weight))
+
 	return []api.Metric{m}
 }
diff --git a/observations/metrics.go b/observations/metrics.go
index 59667b07..adf7d39f 100644
--- a/observations/metrics.go
+++ b/observations/metrics.go
@@ -48,6 +48,8 @@ var (
 
 	BlocksAdded      = stats.Int64("blocks/added", "Total number of blocks added", stats.UnitDimensionless)
 	BlocksAddedError = stats.Int64("blocks/put_errors", "Total number of block/put errors", stats.UnitDimensionless)
+
+	InformerDisk = stats.Int64("informer/disk", "The metric value weight issued by disk informer", stats.UnitDimensionless)
 )
 
 // views, which is just the aggregation of the metrics
@@ -114,6 +116,11 @@ var (
 		Aggregation: view.Sum(),
 	}
 
+	InformerDiskView = &view.View{
+		Measure:     InformerDisk,
+		Aggregation: view.LastValue(),
+	}
+
 	DefaultViews = []*view.View{
 		PinsView,
 		PinsQueuedView,
@@ -126,6 +133,7 @@ var (
 		BlocksAddedSizeView,
 		BlocksAddedView,
 		BlocksAddedErrorView,
+		InformerDiskView,
 	}
 )