X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/b002129afda08bbb4fdbed6e629858a5c298c068..a9f1adf0a3e2df296ce0a8c0a1d735b7e5044baa:/services/keep-balance/balance.go

diff --git a/services/keep-balance/balance.go b/services/keep-balance/balance.go
index 7471aa6cb0..2d1a59e890 100644
--- a/services/keep-balance/balance.go
+++ b/services/keep-balance/balance.go
@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"log"
+	"math"
 	"os"
 	"runtime"
 	"strings"
@@ -79,7 +80,7 @@ func (bal *Balancer) Run(config Config, runOptions RunOptions) (err error) {
 			return
 		}
 	}
-	if err = bal.GetCurrentState(&config.Client); err != nil {
+	if err = bal.GetCurrentState(&config.Client, config.CollectionBatchSize, config.CollectionBuffers); err != nil {
 		return
 	}
 	bal.ComputeChangeSets()
@@ -189,7 +190,7 @@ func (bal *Balancer) ClearTrashLists(c *arvados.Client) error {
 // collection manifests in the database (API server).
 //
 // It encodes the resulting information in BlockStateMap.
-func (bal *Balancer) GetCurrentState(c *arvados.Client) error {
+func (bal *Balancer) GetCurrentState(c *arvados.Client, pageSize, bufs int) error {
 	defer timeMe(bal.Logger, "GetCurrentState")()
 	bal.BlockStateMap = NewBlockStateMap()
 
@@ -223,10 +224,8 @@ func (bal *Balancer) GetCurrentState(c *arvados.Client) error {
 
 	// collQ buffers incoming collections so we can start fetching
 	// the next page without waiting for the current page to
-	// finish processing. (1000 happens to match the page size
-	// used by (*arvados.Client)EachCollection(), but it's OK if
-	// they don't match.)
-	collQ := make(chan arvados.Collection, 1000)
+	// finish processing.
+	collQ := make(chan arvados.Collection, bufs)
 
 	// Start a goroutine to process collections. (We could use a
 	// worker pool here, but even with a single worker we already
@@ -251,7 +250,7 @@ func (bal *Balancer) GetCurrentState(c *arvados.Client) error {
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
-		err = EachCollection(c,
+		err = EachCollection(c, pageSize,
 			func(coll arvados.Collection) error {
 				collQ <- coll
 				if len(errs) > 0 {
@@ -447,9 +446,11 @@ type balancerStats struct {
 	lost, overrep, unref, garbage, underrep, justright blocksNBytes
 	desired, current                                   blocksNBytes
 	pulls, trashes                                     int
+	replHistogram                                      []int
 }
 
 func (bal *Balancer) getStatistics() (s balancerStats) {
+	s.replHistogram = make([]int, 2)
 	bal.BlockStateMap.Apply(func(blkid arvados.SizedDigest, blk *BlockState) {
 		surplus := len(blk.Replicas) - blk.Desired
 		bytes := blkid.Size()
@@ -493,6 +494,11 @@ func (bal *Balancer) getStatistics() (s balancerStats) {
 			s.current.blocks++
 			s.current.bytes += bytes * int64(len(blk.Replicas))
 		}
+
+		for len(s.replHistogram) <= len(blk.Replicas) {
+			s.replHistogram = append(s.replHistogram, 0)
+		}
+		s.replHistogram[len(blk.Replicas)]++
 	})
 	for _, srv := range bal.KeepServices {
 		s.pulls += len(srv.ChangeSet.Pulls)
@@ -521,6 +527,25 @@ func (bal *Balancer) PrintStatistics() {
 		bal.logf("%s: %v\n", srv, srv.ChangeSet)
 	}
 	bal.logf("===")
+	bal.printHistogram(s, 60)
+	bal.logf("===")
+}
+
+func (bal *Balancer) printHistogram(s balancerStats, hashColumns int) {
+	bal.logf("Replication level distribution (counting N replicas on a single server as N):")
+	maxCount := 0
+	for _, count := range s.replHistogram {
+		if maxCount < count {
+			maxCount = count
+		}
+	}
+	hashes := strings.Repeat("#", hashColumns)
+	countWidth := 1 + int(math.Log10(float64(maxCount+1)))
+	scaleCount := 10 * float64(hashColumns) / math.Floor(1+10*math.Log10(float64(maxCount+1)))
+	for repl, count := range s.replHistogram {
+		nHashes := int(scaleCount * math.Log10(float64(count+1)))
+		bal.logf("%2d: %*d %s", repl, countWidth, count, hashes[:nHashes])
+	}
 }
 
 // CheckSanityLate checks for configuration and runtime errors after