+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
package main
import (
+ "bytes"
+ "crypto/md5"
"fmt"
"log"
"math"
- "os"
"runtime"
"sort"
"strings"
"git.curoverse.com/arvados.git/sdk/go/arvados"
"git.curoverse.com/arvados.git/sdk/go/keepclient"
+ "github.com/sirupsen/logrus"
)
-// CheckConfig returns an error if anything is wrong with the given
-// config and runOptions.
-func CheckConfig(config Config, runOptions RunOptions) error {
- if len(config.KeepServiceList.Items) > 0 && config.KeepServiceTypes != nil {
- return fmt.Errorf("cannot specify both KeepServiceList and KeepServiceTypes in config")
- }
- if !runOptions.Once && config.RunPeriod == arvados.Duration(0) {
- return fmt.Errorf("you must either use the -once flag, or specify RunPeriod in config")
- }
- return nil
-}
-
// Balancer compares the contents of keepstore servers with the
// collections stored in Arvados, and issues pull/trash requests
// needed to get (closer to) the optimal data layout.
// BlobSignatureTTL; and all N existing replicas of a given data block
// are in the N best positions in rendezvous probe order.
type Balancer struct {
+ Logger *logrus.Logger
+ Dumper *logrus.Logger
+ Metrics *metrics
+
*BlockStateMap
KeepServices map[string]*KeepService
DefaultReplication int
- Logger *log.Logger
- Dumper *log.Logger
MinMtime int64
- collScanned int
- serviceRoots map[string]string
- errors []error
- mutex sync.Mutex
+ classes []string
+ mounts int
+ mountsByClass map[string]map[*KeepMount]bool
+ collScanned int
+ serviceRoots map[string]string
+ errors []error
+ stats balancerStats
+ mutex sync.Mutex
}
// Run performs a balance operation using the given config and
func (bal *Balancer) Run(config Config, runOptions RunOptions) (nextRunOptions RunOptions, err error) {
nextRunOptions = runOptions
- bal.Dumper = runOptions.Dumper
- bal.Logger = runOptions.Logger
- if bal.Logger == nil {
- bal.Logger = log.New(os.Stderr, "", log.LstdFlags)
- }
-
- defer timeMe(bal.Logger, "Run")()
+ defer bal.time("sweep", "wall clock time to run one full sweep")()
if len(config.KeepServiceList.Items) > 0 {
err = bal.SetKeepServices(config.KeepServiceList)
return
}
+ for _, srv := range bal.KeepServices {
+ err = srv.discoverMounts(&config.Client)
+ if err != nil {
+ return
+ }
+ }
+ bal.cleanupMounts()
+
if err = bal.CheckSanityEarly(&config.Client); err != nil {
return
}
})
}
+func (bal *Balancer) cleanupMounts() {
+ rwdev := map[string]*KeepService{}
+ for _, srv := range bal.KeepServices {
+ for _, mnt := range srv.mounts {
+ if !mnt.ReadOnly && mnt.DeviceID != "" {
+ rwdev[mnt.DeviceID] = srv
+ }
+ }
+ }
+ // Drop the readonly mounts whose device is mounted RW
+ // elsewhere.
+ for _, srv := range bal.KeepServices {
+ var dedup []*KeepMount
+ for _, mnt := range srv.mounts {
+ if mnt.ReadOnly && rwdev[mnt.DeviceID] != nil {
+ bal.logf("skipping srv %s readonly mount %q because same device %q is mounted read-write on srv %s", srv, mnt.UUID, mnt.DeviceID, rwdev[mnt.DeviceID])
+ } else {
+ dedup = append(dedup, mnt)
+ }
+ }
+ srv.mounts = dedup
+ }
+ for _, srv := range bal.KeepServices {
+ for _, mnt := range srv.mounts {
+ if mnt.Replication <= 0 {
+ log.Printf("%s: mount %s reports replication=%d, using replication=1", srv, mnt.UUID, mnt.Replication)
+ mnt.Replication = 1
+ }
+ }
+ }
+}
+
// CheckSanityEarly checks for configuration and runtime errors that
// can be detected before GetCurrentState() and ComputeChangeSets()
// are called.
//
// It encodes the resulting information in BlockStateMap.
func (bal *Balancer) GetCurrentState(c *arvados.Client, pageSize, bufs int) error {
- defer timeMe(bal.Logger, "GetCurrentState")()
+ defer bal.time("get_state", "wall clock time to get current state")()
bal.BlockStateMap = NewBlockStateMap()
dd, err := c.DiscoveryDocument()
bal.DefaultReplication = dd.DefaultCollectionReplication
bal.MinMtime = time.Now().UnixNano() - dd.BlobSignatureTTL*1e9
- errs := make(chan error, 2+len(bal.KeepServices))
+ errs := make(chan error, 1)
wg := sync.WaitGroup{}
- // Start one goroutine for each KeepService: retrieve the
- // index, and add the returned blocks to BlockStateMap.
+ // When a device is mounted more than once, we will get its
+ // index only once, and call AddReplicas on all of the mounts.
+ // equivMount keys are the mounts that will be indexed, and
+ // each value is a list of mounts to apply the received index
+ // to.
+ equivMount := map[*KeepMount][]*KeepMount{}
+ // deviceMount maps each device ID to the one mount that will
+ // be indexed for that device.
+ deviceMount := map[string]*KeepMount{}
for _, srv := range bal.KeepServices {
+ for _, mnt := range srv.mounts {
+ equiv := deviceMount[mnt.DeviceID]
+ if equiv == nil {
+ equiv = mnt
+ if mnt.DeviceID != "" {
+ deviceMount[mnt.DeviceID] = equiv
+ }
+ }
+ equivMount[equiv] = append(equivMount[equiv], mnt)
+ }
+ }
+
+ // Start one goroutine for each (non-redundant) mount:
+ // retrieve the index, and add the returned blocks to
+ // BlockStateMap.
+ for _, mounts := range equivMount {
wg.Add(1)
- go func(srv *KeepService) {
+ go func(mounts []*KeepMount) {
defer wg.Done()
- bal.logf("%s: retrieve index", srv)
- idx, err := srv.Index(c, "")
+ bal.logf("mount %s: retrieve index from %s", mounts[0], mounts[0].KeepService)
+ idx, err := mounts[0].KeepService.IndexMount(c, mounts[0].UUID, "")
if err != nil {
- errs <- fmt.Errorf("%s: %v", srv, err)
+ select {
+ case errs <- fmt.Errorf("%s: retrieve index: %v", mounts[0], err):
+ default:
+ }
return
}
if len(errs) > 0 {
// will be wasted.
return
}
- bal.logf("%s: add %d replicas to map", srv, len(idx))
- bal.BlockStateMap.AddReplicas(srv, idx)
- bal.logf("%s: done", srv)
- }(srv)
+ for _, mount := range mounts {
+ bal.logf("%s: add %d entries to map", mount, len(idx))
+ bal.BlockStateMap.AddReplicas(mount, idx)
+ bal.logf("%s: added %d entries to map at %dx (%d replicas)", mount, len(idx), mount.Replication, len(idx)*mount.Replication)
+ }
+ bal.logf("mount %s: index done", mounts[0])
+ }(mounts)
}
// collQ buffers incoming collections so we can start fetching
for coll := range collQ {
err := bal.addCollection(coll)
if err != nil {
- errs <- err
+ select {
+ case errs <- err:
+ default:
+ }
for range collQ {
}
return
})
close(collQ)
if err != nil {
- errs <- err
+ select {
+ case errs <- err:
+ default:
+ }
}
}()
repl = *coll.ReplicationDesired
}
debugf("%v: %d block x%d", coll.UUID, len(blkids), repl)
- bal.BlockStateMap.IncreaseDesired(repl, blkids)
+ bal.BlockStateMap.IncreaseDesired(coll.StorageClassesDesired, repl, blkids)
return nil
}
func (bal *Balancer) ComputeChangeSets() {
// This just calls balanceBlock() once for each block, using a
// pool of worker goroutines.
- defer timeMe(bal.Logger, "ComputeChangeSets")()
- bal.setupServiceRoots()
+ defer bal.time("changeset_compute", "wall clock time to compute changesets")()
+ bal.setupLookupTables()
type balanceTask struct {
blkid arvados.SizedDigest
blk *BlockState
}
- nWorkers := 1 + runtime.NumCPU()
- todo := make(chan balanceTask, nWorkers)
- var wg sync.WaitGroup
- for i := 0; i < nWorkers; i++ {
- wg.Add(1)
- go func() {
- for work := range todo {
- bal.balanceBlock(work.blkid, work.blk)
+ workers := runtime.GOMAXPROCS(-1)
+ todo := make(chan balanceTask, workers)
+ go func() {
+ bal.BlockStateMap.Apply(func(blkid arvados.SizedDigest, blk *BlockState) {
+ todo <- balanceTask{
+ blkid: blkid,
+ blk: blk,
}
- wg.Done()
- }()
- }
- bal.BlockStateMap.Apply(func(blkid arvados.SizedDigest, blk *BlockState) {
- todo <- balanceTask{
- blkid: blkid,
- blk: blk,
+ })
+ close(todo)
+ }()
+ results := make(chan balanceResult, workers)
+ go func() {
+ var wg sync.WaitGroup
+ for i := 0; i < workers; i++ {
+ wg.Add(1)
+ go func() {
+ for work := range todo {
+ results <- bal.balanceBlock(work.blkid, work.blk)
+ }
+ wg.Done()
+ }()
}
- })
- close(todo)
- wg.Wait()
+ wg.Wait()
+ close(results)
+ }()
+ bal.collectStatistics(results)
}
-func (bal *Balancer) setupServiceRoots() {
+func (bal *Balancer) setupLookupTables() {
bal.serviceRoots = make(map[string]string)
+ bal.classes = []string{"default"}
+ bal.mountsByClass = map[string]map[*KeepMount]bool{"default": {}}
+ bal.mounts = 0
for _, srv := range bal.KeepServices {
bal.serviceRoots[srv.UUID] = srv.UUID
+ for _, mnt := range srv.mounts {
+ bal.mounts++
+
+ // All mounts on a read-only service are
+ // effectively read-only.
+ mnt.ReadOnly = mnt.ReadOnly || srv.ReadOnly
+
+ if len(mnt.StorageClasses) == 0 {
+ bal.mountsByClass["default"][mnt] = true
+ continue
+ }
+ for _, class := range mnt.StorageClasses {
+ if mbc := bal.mountsByClass[class]; mbc == nil {
+ bal.classes = append(bal.classes, class)
+ bal.mountsByClass[class] = map[*KeepMount]bool{mnt: true}
+ } else {
+ mbc[mnt] = true
+ }
+ }
+ }
}
+ // Consider classes in lexicographic order to avoid flapping
+ // between balancing runs. The outcome of the "prefer a mount
+ // we're already planning to use for a different storage
+ // class" case in balanceBlock depends on the order classes
+ // are considered.
+ sort.Strings(bal.classes)
}
const (
changeNone: "none",
}
+type balanceResult struct {
+ blk *BlockState
+ blkid arvados.SizedDigest
+ have int
+ want int
+ classState map[string]balancedBlockState
+}
+
// balanceBlock compares current state to desired state for a single
// block, and makes the appropriate ChangeSet calls.
-func (bal *Balancer) balanceBlock(blkid arvados.SizedDigest, blk *BlockState) {
+func (bal *Balancer) balanceBlock(blkid arvados.SizedDigest, blk *BlockState) balanceResult {
debugf("balanceBlock: %v %+v", blkid, blk)
+
+ type slot struct {
+ mnt *KeepMount // never nil
+ repl *Replica // replica already stored here (or nil)
+ want bool // we should pull/leave a replica here
+ }
+
+ // Build a list of all slots (one per mounted volume).
+ slots := make([]slot, 0, bal.mounts)
+ for _, srv := range bal.KeepServices {
+ for _, mnt := range srv.mounts {
+ var repl *Replica
+ for r := range blk.Replicas {
+ if blk.Replicas[r].KeepMount == mnt {
+ repl = &blk.Replicas[r]
+ }
+ }
+ // Initial value of "want" is "have, and can't
+ // delete". These untrashable replicas get
+ // prioritized when sorting slots: otherwise,
+ // non-optimal readonly copies would cause us
+ // to overreplicate.
+ slots = append(slots, slot{
+ mnt: mnt,
+ repl: repl,
+ want: repl != nil && mnt.ReadOnly,
+ })
+ }
+ }
+
uuids := keepclient.NewRootSorter(bal.serviceRoots, string(blkid[:32])).GetSortedRoots()
- hasRepl := make(map[string]Replica, len(bal.serviceRoots))
- for _, repl := range blk.Replicas {
- hasRepl[repl.UUID] = repl
- // TODO: when multiple copies are on one server, use
- // the oldest one that doesn't have a timestamp
- // collision with other replicas.
- }
- // number of replicas already found in positions better than
- // the position we're contemplating now.
- reportedBestRepl := 0
- // To be safe we assume two replicas with the same Mtime are
- // in fact the same replica being reported more than
- // once. len(uniqueBestRepl) is the number of distinct
- // replicas in the best rendezvous positions we've considered
- // so far.
- uniqueBestRepl := make(map[int64]bool, len(bal.serviceRoots))
- // pulls is the number of Pull changes we have already
- // requested. (For purposes of deciding whether to Pull to
- // rendezvous position N, we should assume all pulls we have
- // requested on rendezvous positions M<N will be successful.)
- pulls := 0
- var changes []string
- for _, uuid := range uuids {
- change := changeNone
+ srvRendezvous := make(map[*KeepService]int, len(uuids))
+ for i, uuid := range uuids {
srv := bal.KeepServices[uuid]
- // TODO: request a Touch if Mtime is duplicated.
- repl, ok := hasRepl[srv.UUID]
- if ok {
- // This service has a replica. We should
- // delete it if [1] we already have enough
- // distinct replicas in better rendezvous
- // positions and [2] this replica's Mtime is
- // distinct from all of the better replicas'
- // Mtimes.
- if !srv.ReadOnly &&
- repl.Mtime < bal.MinMtime &&
- len(uniqueBestRepl) >= blk.Desired &&
- !uniqueBestRepl[repl.Mtime] {
- srv.AddTrash(Trash{
- SizedDigest: blkid,
- Mtime: repl.Mtime,
- })
- change = changeTrash
+ srvRendezvous[srv] = i
+ }
+
+ // Below we set underreplicated=true if we find any storage
+ // class that's currently underreplicated -- in that case we
+ // won't want to trash any replicas.
+ underreplicated := false
+
+ classState := make(map[string]balancedBlockState, len(bal.classes))
+ unsafeToDelete := make(map[int64]bool, len(slots))
+ for _, class := range bal.classes {
+ desired := blk.Desired[class]
+
+ countedDev := map[string]bool{}
+ have := 0
+ for _, slot := range slots {
+ if slot.repl != nil && bal.mountsByClass[class][slot.mnt] && !countedDev[slot.mnt.DeviceID] {
+ have += slot.mnt.Replication
+ if slot.mnt.DeviceID != "" {
+ countedDev[slot.mnt.DeviceID] = true
+ }
+ }
+ }
+ classState[class] = balancedBlockState{
+ desired: desired,
+ surplus: have - desired,
+ }
+
+ if desired == 0 {
+ continue
+ }
+
+ // Sort the slots by desirability.
+ sort.Slice(slots, func(i, j int) bool {
+ si, sj := slots[i], slots[j]
+ if classi, classj := bal.mountsByClass[class][si.mnt], bal.mountsByClass[class][sj.mnt]; classi != classj {
+ // Prefer a mount that satisfies the
+ // desired class.
+ return bal.mountsByClass[class][si.mnt]
+ } else if si.want != sj.want {
+ // Prefer a mount that will have a
+ // replica no matter what we do here
+ // -- either because it already has an
+ // untrashable replica, or because we
+ // already need it to satisfy a
+ // different storage class.
+ return si.want
+ } else if orderi, orderj := srvRendezvous[si.mnt.KeepService], srvRendezvous[sj.mnt.KeepService]; orderi != orderj {
+ // Prefer a better rendezvous
+ // position.
+ return orderi < orderj
+ } else if repli, replj := si.repl != nil, sj.repl != nil; repli != replj {
+ // Prefer a mount that already has a
+ // replica.
+ return repli
} else {
- change = changeStay
+ // If pull/trash turns out to be
+ // needed, distribute the
+ // new/remaining replicas uniformly
+ // across qualifying mounts on a given
+ // server.
+ return rendezvousLess(si.mnt.DeviceID, sj.mnt.DeviceID, blkid)
+ }
+ })
+
+ // Servers/mounts/devices (with or without existing
+ // replicas) that are part of the best achievable
+ // layout for this storage class.
+ wantSrv := map[*KeepService]bool{}
+ wantMnt := map[*KeepMount]bool{}
+ wantDev := map[string]bool{}
+ // Positions (with existing replicas) that have been
+ // protected (via unsafeToDelete) to ensure we don't
+ // reduce replication below desired level when
+ // trashing replicas that aren't optimal positions for
+ // any storage class.
+ protMnt := map[*KeepMount]bool{}
+ // Replication planned so far (corresponds to wantMnt).
+ replWant := 0
+ // Protected replication (corresponds to protMnt).
+ replProt := 0
+
+ // trySlot tries using a slot to meet requirements,
+ // and returns true if all requirements are met.
+ trySlot := func(i int) bool {
+ slot := slots[i]
+ if wantMnt[slot.mnt] || wantDev[slot.mnt.DeviceID] {
+ // Already allocated a replica to this
+ // backend device, possibly on a
+ // different server.
+ return false
+ }
+ if replProt < desired && slot.repl != nil && !protMnt[slot.mnt] {
+ unsafeToDelete[slot.repl.Mtime] = true
+ protMnt[slot.mnt] = true
+ replProt += slot.mnt.Replication
+ }
+ if replWant < desired && (slot.repl != nil || !slot.mnt.ReadOnly) {
+ slots[i].want = true
+ wantSrv[slot.mnt.KeepService] = true
+ wantMnt[slot.mnt] = true
+ if slot.mnt.DeviceID != "" {
+ wantDev[slot.mnt.DeviceID] = true
+ }
+ replWant += slot.mnt.Replication
+ }
+ return replProt >= desired && replWant >= desired
+ }
+
+ // First try to achieve desired replication without
+ // using the same server twice.
+ done := false
+ for i := 0; i < len(slots) && !done; i++ {
+ if !wantSrv[slots[i].mnt.KeepService] {
+ done = trySlot(i)
+ }
+ }
+
+ // If that didn't suffice, do another pass without the
+ // "distinct services" restriction. (Achieving the
+ // desired volume replication on fewer than the
+ // desired number of services is better than
+ // underreplicating.)
+ for i := 0; i < len(slots) && !done; i++ {
+ done = trySlot(i)
+ }
+
+ if !underreplicated {
+ safe := 0
+ for _, slot := range slots {
+ if slot.repl == nil || !bal.mountsByClass[class][slot.mnt] {
+ continue
+ }
+ if safe += slot.mnt.Replication; safe >= desired {
+ break
+ }
+ }
+ underreplicated = safe < desired
+ }
+
+ // set the unachievable flag if there aren't enough
+ // slots offering the relevant storage class. (This is
+ // as easy as checking slots[desired] because we
+ // already sorted the qualifying slots to the front.)
+ if desired >= len(slots) || !bal.mountsByClass[class][slots[desired].mnt] {
+ cs := classState[class]
+ cs.unachievable = true
+ classState[class] = cs
+ }
+
+ // Avoid deleting wanted replicas from devices that
+ // are mounted on multiple servers -- even if they
+ // haven't already been added to unsafeToDelete
+ // because the servers report different Mtimes.
+ for _, slot := range slots {
+ if slot.repl != nil && wantDev[slot.mnt.DeviceID] {
+ unsafeToDelete[slot.repl.Mtime] = true
}
- uniqueBestRepl[repl.Mtime] = true
- reportedBestRepl++
- } else if pulls+reportedBestRepl < blk.Desired &&
- len(blk.Replicas) > 0 &&
- !srv.ReadOnly {
- // This service doesn't have a replica. We
- // should pull one to this server if we don't
- // already have enough (existing+requested)
- // replicas in better rendezvous positions.
- srv.AddPull(Pull{
+ }
+ }
+
+ // TODO: If multiple replicas are trashable, prefer the oldest
+ // replica that doesn't have a timestamp collision with
+ // others.
+
+ countedDev := map[string]bool{}
+ var have, want int
+ for _, slot := range slots {
+ if countedDev[slot.mnt.DeviceID] {
+ continue
+ }
+ if slot.want {
+ want += slot.mnt.Replication
+ }
+ if slot.repl != nil {
+ have += slot.mnt.Replication
+ }
+ if slot.mnt.DeviceID != "" {
+ countedDev[slot.mnt.DeviceID] = true
+ }
+ }
+
+ var changes []string
+ for _, slot := range slots {
+ // TODO: request a Touch if Mtime is duplicated.
+ var change int
+ switch {
+ case !underreplicated && !slot.want && slot.repl != nil && slot.repl.Mtime < bal.MinMtime && !unsafeToDelete[slot.repl.Mtime]:
+ slot.mnt.KeepService.AddTrash(Trash{
+ SizedDigest: blkid,
+ Mtime: slot.repl.Mtime,
+ From: slot.mnt,
+ })
+ change = changeTrash
+ case len(blk.Replicas) == 0:
+ change = changeNone
+ case slot.repl == nil && slot.want && !slot.mnt.ReadOnly:
+ slot.mnt.KeepService.AddPull(Pull{
SizedDigest: blkid,
- Source: blk.Replicas[0].KeepService,
+ From: blk.Replicas[0].KeepMount.KeepService,
+ To: slot.mnt,
})
- pulls++
change = changePull
+ default:
+ change = changeStay
}
if bal.Dumper != nil {
- changes = append(changes, fmt.Sprintf("%s:%d=%s,%d", srv.ServiceHost, srv.ServicePort, changeName[change], repl.Mtime))
+ var mtime int64
+ if slot.repl != nil {
+ mtime = slot.repl.Mtime
+ }
+ srv := slot.mnt.KeepService
+ changes = append(changes, fmt.Sprintf("%s:%d/%s=%s,%d", srv.ServiceHost, srv.ServicePort, slot.mnt.UUID, changeName[change], mtime))
}
}
if bal.Dumper != nil {
- bal.Dumper.Printf("%s have=%d want=%d %s", blkid, len(blk.Replicas), blk.Desired, strings.Join(changes, " "))
+ bal.Dumper.Printf("%s have=%d want=%v %s", blkid, have, want, strings.Join(changes, " "))
+ }
+ return balanceResult{
+ blk: blk,
+ blkid: blkid,
+ have: have,
+ want: want,
+ classState: classState,
}
}
}
type balancerStats struct {
- lost, overrep, unref, garbage, underrep, justright blocksNBytes
- desired, current blocksNBytes
- pulls, trashes int
- replHistogram []int
+ lost blocksNBytes
+ overrep blocksNBytes
+ unref blocksNBytes
+ garbage blocksNBytes
+ underrep blocksNBytes
+ unachievable blocksNBytes
+ justright blocksNBytes
+ desired blocksNBytes
+ current blocksNBytes
+ pulls int
+ trashes int
+ replHistogram []int
+ classStats map[string]replicationStats
+
+ // collectionBytes / collectionBlockBytes = deduplication ratio
+ collectionBytes int64 // sum(bytes in referenced blocks) across all collections
+ collectionBlockBytes int64 // sum(block size) across all blocks referenced by collections
+ collectionBlockRefs int64 // sum(number of blocks referenced) across all collections
+ collectionBlocks int64 // number of blocks referenced by any collection
+}
+
+func (s *balancerStats) dedupByteRatio() float64 {
+ if s.collectionBlockBytes == 0 {
+ return 0
+ }
+ return float64(s.collectionBytes) / float64(s.collectionBlockBytes)
+}
+
+func (s *balancerStats) dedupBlockRatio() float64 {
+ if s.collectionBlocks == 0 {
+ return 0
+ }
+ return float64(s.collectionBlockRefs) / float64(s.collectionBlocks)
+}
+
+type replicationStats struct {
+ desired blocksNBytes
+ surplus blocksNBytes
+ short blocksNBytes
+ unachievable blocksNBytes
+}
+
+type balancedBlockState struct {
+ desired int
+ surplus int
+ unachievable bool
}
-func (bal *Balancer) getStatistics() (s balancerStats) {
+func (bal *Balancer) collectStatistics(results <-chan balanceResult) {
+ var 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()
+ s.classStats = make(map[string]replicationStats, len(bal.classes))
+ for result := range results {
+ surplus := result.have - result.want
+ bytes := result.blkid.Size()
+
+ if rc := int64(result.blk.RefCount); rc > 0 {
+ s.collectionBytes += rc * bytes
+ s.collectionBlockBytes += bytes
+ s.collectionBlockRefs += rc
+ s.collectionBlocks++
+ }
+
+ for class, state := range result.classState {
+ cs := s.classStats[class]
+ if state.unachievable {
+ cs.unachievable.blocks++
+ cs.unachievable.bytes += bytes
+ }
+ if state.desired > 0 {
+ cs.desired.replicas += state.desired
+ cs.desired.blocks++
+ cs.desired.bytes += bytes * int64(state.desired)
+ }
+ if state.surplus > 0 {
+ cs.surplus.replicas += state.surplus
+ cs.surplus.blocks++
+ cs.surplus.bytes += bytes * int64(state.surplus)
+ } else if state.surplus < 0 {
+ cs.short.replicas += -state.surplus
+ cs.short.blocks++
+ cs.short.bytes += bytes * int64(-state.surplus)
+ }
+ s.classStats[class] = cs
+ }
+
switch {
- case len(blk.Replicas) == 0 && blk.Desired > 0:
+ case result.have == 0 && result.want > 0:
s.lost.replicas -= surplus
s.lost.blocks++
s.lost.bytes += bytes * int64(-surplus)
- case len(blk.Replicas) < blk.Desired:
+ case surplus < 0:
s.underrep.replicas -= surplus
s.underrep.blocks++
s.underrep.bytes += bytes * int64(-surplus)
- case len(blk.Replicas) > 0 && blk.Desired == 0:
+ case surplus > 0 && result.want == 0:
counter := &s.garbage
- for _, r := range blk.Replicas {
+ for _, r := range result.blk.Replicas {
if r.Mtime >= bal.MinMtime {
counter = &s.unref
break
counter.replicas += surplus
counter.blocks++
counter.bytes += bytes * int64(surplus)
- case len(blk.Replicas) > blk.Desired:
+ case surplus > 0:
s.overrep.replicas += surplus
s.overrep.blocks++
- s.overrep.bytes += bytes * int64(len(blk.Replicas)-blk.Desired)
+ s.overrep.bytes += bytes * int64(result.have-result.want)
default:
- s.justright.replicas += blk.Desired
+ s.justright.replicas += result.want
s.justright.blocks++
- s.justright.bytes += bytes * int64(blk.Desired)
+ s.justright.bytes += bytes * int64(result.want)
}
- if blk.Desired > 0 {
- s.desired.replicas += blk.Desired
+ if result.want > 0 {
+ s.desired.replicas += result.want
s.desired.blocks++
- s.desired.bytes += bytes * int64(blk.Desired)
+ s.desired.bytes += bytes * int64(result.want)
}
- if len(blk.Replicas) > 0 {
- s.current.replicas += len(blk.Replicas)
+ if result.have > 0 {
+ s.current.replicas += result.have
s.current.blocks++
- s.current.bytes += bytes * int64(len(blk.Replicas))
+ s.current.bytes += bytes * int64(result.have)
}
- for len(s.replHistogram) <= len(blk.Replicas) {
+ for len(s.replHistogram) <= result.have {
s.replHistogram = append(s.replHistogram, 0)
}
- s.replHistogram[len(blk.Replicas)]++
- })
+ s.replHistogram[result.have]++
+ }
for _, srv := range bal.KeepServices {
s.pulls += len(srv.ChangeSet.Pulls)
s.trashes += len(srv.ChangeSet.Trashes)
}
- return
+ bal.stats = s
+ bal.Metrics.UpdateStats(s)
}
// PrintStatistics writes statistics about the computed changes to
// bal.Logger. It should not be called until ComputeChangeSets has
// finished.
func (bal *Balancer) PrintStatistics() {
- s := bal.getStatistics()
bal.logf("===")
- bal.logf("%s lost (0=have<want)", s.lost)
- bal.logf("%s underreplicated (0<have<want)", s.underrep)
- bal.logf("%s just right (have=want)", s.justright)
- bal.logf("%s overreplicated (have>want>0)", s.overrep)
- bal.logf("%s unreferenced (have>want=0, new)", s.unref)
- bal.logf("%s garbage (have>want=0, old)", s.garbage)
+ bal.logf("%s lost (0=have<want)", bal.stats.lost)
+ bal.logf("%s underreplicated (0<have<want)", bal.stats.underrep)
+ bal.logf("%s just right (have=want)", bal.stats.justright)
+ bal.logf("%s overreplicated (have>want>0)", bal.stats.overrep)
+ bal.logf("%s unreferenced (have>want=0, new)", bal.stats.unref)
+ bal.logf("%s garbage (have>want=0, old)", bal.stats.garbage)
+ for _, class := range bal.classes {
+ cs := bal.stats.classStats[class]
+ bal.logf("===")
+ bal.logf("storage class %q: %s desired", class, cs.desired)
+ bal.logf("storage class %q: %s short", class, cs.short)
+ bal.logf("storage class %q: %s surplus", class, cs.surplus)
+ bal.logf("storage class %q: %s unachievable", class, cs.unachievable)
+ }
bal.logf("===")
- bal.logf("%s total commitment (excluding unreferenced)", s.desired)
- bal.logf("%s total usage", s.current)
+ bal.logf("%s total commitment (excluding unreferenced)", bal.stats.desired)
+ bal.logf("%s total usage", bal.stats.current)
bal.logf("===")
for _, srv := range bal.KeepServices {
bal.logf("%s: %v\n", srv, srv.ChangeSet)
}
bal.logf("===")
- bal.printHistogram(s, 60)
+ bal.printHistogram(60)
bal.logf("===")
}
-func (bal *Balancer) printHistogram(s balancerStats, hashColumns int) {
+func (bal *Balancer) printHistogram(hashColumns int) {
bal.logf("Replication level distribution (counting N replicas on a single server as N):")
maxCount := 0
- for _, count := range s.replHistogram {
+ for _, count := range bal.stats.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 {
+ for repl, count := range bal.stats.replHistogram {
nHashes := int(scaleCount * math.Log10(float64(count+1)))
bal.logf("%2d: %*d %s", repl, countWidth, count, hashes[:nHashes])
}
anyDesired := false
bal.BlockStateMap.Apply(func(_ arvados.SizedDigest, blk *BlockState) {
- if blk.Desired > 0 {
- anyDesired = true
+ for _, desired := range blk.Desired {
+ if desired > 0 {
+ anyDesired = true
+ break
+ }
}
})
if !anyDesired {
// existing blocks that are either underreplicated or poorly
// distributed according to rendezvous hashing.
func (bal *Balancer) CommitPulls(c *arvados.Client) error {
+ defer bal.time("send_pull_lists", "wall clock time to send pull lists")()
return bal.commitAsync(c, "send pull list",
func(srv *KeepService) error {
return srv.CommitPulls(c)
// keepstore servers. This has the effect of deleting blocks that are
// overreplicated or unreferenced.
func (bal *Balancer) CommitTrash(c *arvados.Client) error {
+ defer bal.time("send_trash_lists", "wall clock time to send trash lists")()
return bal.commitAsync(c, "send trash list",
func(srv *KeepService) error {
return srv.CommitTrash(c)
var err error
defer func() { errs <- err }()
label := fmt.Sprintf("%s: %v", srv, label)
- defer timeMe(bal.Logger, label)()
err = f(srv)
if err != nil {
err = fmt.Errorf("%s: %v", label, err)
bal.Logger.Printf(f, args...)
}
}
+
+func (bal *Balancer) time(name, help string) func() {
+ observer := bal.Metrics.DurationObserver(name+"_seconds", help)
+ t0 := time.Now()
+ bal.Logger.Printf("%s: start", name)
+ return func() {
+ dur := time.Since(t0)
+ observer.Observe(dur.Seconds())
+ bal.Logger.Printf("%s: took %vs", name, dur.Seconds())
+ }
+}
+
+// Rendezvous hash sort function. Less efficient than sorting on
+// precomputed rendezvous hashes, but also rarely used.
+func rendezvousLess(i, j string, blkid arvados.SizedDigest) bool {
+ a := md5.Sum([]byte(string(blkid[:32]) + i))
+ b := md5.Sum([]byte(string(blkid[:32]) + j))
+ return bytes.Compare(a[:], b[:]) < 0
+}
projects / arvados.git / blobdiff