//
// SPDX-License-Identifier: AGPL-3.0
-package main
+package keepbalance
import (
"bytes"
+ "context"
"crypto/md5"
+ "errors"
"fmt"
+ "io"
+ "io/ioutil"
"log"
"math"
+ "os"
+ "regexp"
"runtime"
"sort"
+ "strconv"
"strings"
"sync"
+ "sync/atomic"
+ "syscall"
"time"
- "git.curoverse.com/arvados.git/sdk/go/arvados"
- "git.curoverse.com/arvados.git/sdk/go/keepclient"
+ "git.arvados.org/arvados.git/lib/controller/dblock"
+ "git.arvados.org/arvados.git/sdk/go/arvados"
+ "git.arvados.org/arvados.git/sdk/go/keepclient"
+ "github.com/jmoiron/sqlx"
"github.com/sirupsen/logrus"
)
// BlobSignatureTTL; and all N existing replicas of a given data block
// are in the N best positions in rendezvous probe order.
type Balancer struct {
+ DB *sqlx.DB
Logger logrus.FieldLogger
Dumper logrus.FieldLogger
Metrics *metrics
+ ChunkPrefix string
+ LostBlocksFile string
+
*BlockStateMap
KeepServices map[string]*KeepService
DefaultReplication int
classes []string
mounts int
mountsByClass map[string]map[*KeepMount]bool
- collScanned int
+ collScanned int64
serviceRoots map[string]string
errors []error
stats balancerStats
mutex sync.Mutex
+ lostBlocks io.Writer
}
// Run performs a balance operation using the given config and
// subsequent balance operation.
//
// Run should only be called once on a given Balancer object.
-//
-// Typical usage:
-//
-// runOptions, err = (&Balancer{}).Run(config, runOptions)
-func (bal *Balancer) Run(config Config, runOptions RunOptions) (nextRunOptions RunOptions, err error) {
+func (bal *Balancer) Run(ctx context.Context, client *arvados.Client, cluster *arvados.Cluster, runOptions RunOptions) (nextRunOptions RunOptions, err error) {
nextRunOptions = runOptions
+ bal.logf("acquiring active lock")
+ if !dblock.KeepBalanceActive.Lock(ctx, func(context.Context) (*sqlx.DB, error) { return bal.DB, nil }) {
+ // context canceled
+ return
+ }
+ defer dblock.KeepBalanceActive.Unlock()
+
defer bal.time("sweep", "wall clock time to run one full sweep")()
- if len(config.KeepServiceList.Items) > 0 {
- err = bal.SetKeepServices(config.KeepServiceList)
+ ctx, cancel := context.WithDeadline(ctx, time.Now().Add(cluster.Collections.BalanceTimeout.Duration()))
+ defer cancel()
+
+ go bal.reportMemorySize(ctx)
+
+ var lbFile *os.File
+ if bal.LostBlocksFile != "" {
+ tmpfn := bal.LostBlocksFile + ".tmp"
+ lbFile, err = os.OpenFile(tmpfn, os.O_CREATE|os.O_WRONLY, 0777)
+ if err != nil {
+ return
+ }
+ defer lbFile.Close()
+ err = syscall.Flock(int(lbFile.Fd()), syscall.LOCK_EX|syscall.LOCK_NB)
+ if err != nil {
+ return
+ }
+ defer func() {
+ // Remove the tempfile only if we didn't get
+ // as far as successfully renaming it.
+ if lbFile != nil {
+ os.Remove(tmpfn)
+ }
+ }()
+ bal.lostBlocks = lbFile
} else {
- err = bal.DiscoverKeepServices(&config.Client, config.KeepServiceTypes)
+ bal.lostBlocks = ioutil.Discard
}
+
+ err = bal.DiscoverKeepServices(client)
if err != nil {
return
}
for _, srv := range bal.KeepServices {
- err = srv.discoverMounts(&config.Client)
+ err = srv.discoverMounts(client)
if err != nil {
return
}
}
bal.cleanupMounts()
- if err = bal.CheckSanityEarly(&config.Client); err != nil {
+ if err = bal.CheckSanityEarly(client); err != nil {
return
}
+
+ // On a big site, indexing and sending trash/pull lists can
+ // take much longer than the usual 5 minute client
+ // timeout. From here on, we rely on the context deadline
+ // instead, aborting the entire operation if any part takes
+ // too long.
+ client.Timeout = 0
+
rs := bal.rendezvousState()
if runOptions.CommitTrash && rs != runOptions.SafeRendezvousState {
if runOptions.SafeRendezvousState != "" {
bal.logf("notice: KeepServices list has changed since last run")
}
bal.logf("clearing existing trash lists, in case the new rendezvous order differs from previous run")
- if err = bal.ClearTrashLists(&config.Client); err != nil {
+ if err = bal.ClearTrashLists(ctx, client); err != nil {
return
}
// The current rendezvous state becomes "safe" (i.e.,
// succeed in clearing existing trash lists.
nextRunOptions.SafeRendezvousState = rs
}
- if err = bal.GetCurrentState(&config.Client, config.CollectionBatchSize, config.CollectionBuffers); err != nil {
+
+ if err = bal.GetCurrentState(ctx, client, cluster.Collections.BalanceCollectionBatch, cluster.Collections.BalanceCollectionBuffers); err != nil {
return
}
bal.ComputeChangeSets()
if err = bal.CheckSanityLate(); err != nil {
return
}
+ if lbFile != nil {
+ err = lbFile.Sync()
+ if err != nil {
+ return
+ }
+ err = os.Rename(bal.LostBlocksFile+".tmp", bal.LostBlocksFile)
+ if err != nil {
+ return
+ }
+ lbFile = nil
+ }
if runOptions.CommitPulls {
- err = bal.CommitPulls(&config.Client)
+ err = bal.CommitPulls(ctx, client)
if err != nil {
// Skip trash if we can't pull. (Too cautious?)
return
}
}
if runOptions.CommitTrash {
- err = bal.CommitTrash(&config.Client)
+ err = bal.CommitTrash(ctx, client)
+ if err != nil {
+ return
+ }
+ }
+ if runOptions.CommitConfirmedFields {
+ err = bal.updateCollections(ctx, client, cluster)
+ if err != nil {
+ return
+ }
}
return
}
// DiscoverKeepServices sets the list of KeepServices by calling the
// API to get a list of all services, and selecting the ones whose
-// ServiceType is in okTypes.
-func (bal *Balancer) DiscoverKeepServices(c *arvados.Client, okTypes []string) error {
+// ServiceType is "disk"
+func (bal *Balancer) DiscoverKeepServices(c *arvados.Client) error {
bal.KeepServices = make(map[string]*KeepService)
- ok := make(map[string]bool)
- for _, t := range okTypes {
- ok[t] = true
- }
return c.EachKeepService(func(srv arvados.KeepService) error {
- if ok[srv.ServiceType] {
+ if srv.ServiceType == "disk" {
bal.KeepServices[srv.UUID] = &KeepService{
KeepService: srv,
ChangeSet: &ChangeSet{},
rwdev := map[string]*KeepService{}
for _, srv := range bal.KeepServices {
for _, mnt := range srv.mounts {
- if !mnt.ReadOnly && mnt.DeviceID != "" {
- rwdev[mnt.DeviceID] = srv
+ if !mnt.ReadOnly {
+ rwdev[mnt.UUID] = srv
}
}
}
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])
+ if mnt.ReadOnly && rwdev[mnt.UUID] != nil {
+ bal.logf("skipping srv %s readonly mount %q because same volume is mounted read-write on srv %s", srv, mnt.UUID, rwdev[mnt.UUID])
} else {
dedup = append(dedup, mnt)
}
return fmt.Errorf("config error: %s: proxy servers cannot be balanced", srv)
}
}
+ for _, c := range bal.ChunkPrefix {
+ if !strings.ContainsRune("0123456789abcdef", c) {
+ return fmt.Errorf("invalid char %q in chunk prefix %q: only lowercase hex digits make sense", string(c), bal.ChunkPrefix)
+ }
+ }
+ if len(bal.ChunkPrefix) > 32 {
+ return fmt.Errorf("invalid chunk prefix %q: longer than a block hash", bal.ChunkPrefix)
+ }
+
+ mountProblem := false
+ type deviceMount struct {
+ srv *KeepService
+ mnt *KeepMount
+ }
+ deviceMounted := map[string]deviceMount{} // DeviceID -> mount
+ for _, srv := range bal.KeepServices {
+ for _, mnt := range srv.mounts {
+ if first, dup := deviceMounted[mnt.DeviceID]; dup && first.mnt.UUID != mnt.UUID && mnt.DeviceID != "" {
+ bal.logf("config error: device %s is mounted with multiple volume UUIDs: %s on %s, and %s on %s",
+ mnt.DeviceID,
+ first.mnt.UUID, first.srv,
+ mnt.UUID, srv)
+ mountProblem = true
+ continue
+ }
+ deviceMounted[mnt.DeviceID] = deviceMount{srv, mnt}
+ }
+ }
+ if mountProblem {
+ return errors.New("cannot continue with config errors (see above)")
+ }
+
+ var checkPage arvados.CollectionList
+ if err = c.RequestAndDecode(&checkPage, "GET", "arvados/v1/collections", nil, arvados.ResourceListParams{
+ Limit: new(int),
+ Count: "exact",
+ IncludeTrash: true,
+ IncludeOldVersions: true,
+ Filters: []arvados.Filter{{
+ Attr: "modified_at",
+ Operator: "=",
+ Operand: nil,
+ }},
+ }); err != nil {
+ return err
+ } else if n := checkPage.ItemsAvailable; n > 0 {
+ return fmt.Errorf("%d collections exist with null modified_at; cannot fetch reliably", n)
+ }
+
return nil
}
// We avoid this problem if we clear all trash lists before getting
// indexes. (We also assume there is only one rebalancing process
// running at a time.)
-func (bal *Balancer) ClearTrashLists(c *arvados.Client) error {
+func (bal *Balancer) ClearTrashLists(ctx context.Context, c *arvados.Client) error {
for _, srv := range bal.KeepServices {
srv.ChangeSet = &ChangeSet{}
}
- return bal.CommitTrash(c)
+ return bal.CommitTrash(ctx, c)
}
// GetCurrentState determines the current replication state, and the
// collection manifests in the database (API server).
//
// It encodes the resulting information in BlockStateMap.
-func (bal *Balancer) GetCurrentState(c *arvados.Client, pageSize, bufs int) error {
+func (bal *Balancer) GetCurrentState(ctx context.Context, c *arvados.Client, pageSize, bufs int) error {
+ ctx, cancel := context.WithCancel(ctx)
+ defer cancel()
+
defer bal.time("get_state", "wall clock time to get current state")()
bal.BlockStateMap = NewBlockStateMap()
deviceMount := map[string]*KeepMount{}
for _, srv := range bal.KeepServices {
for _, mnt := range srv.mounts {
- equiv := deviceMount[mnt.DeviceID]
+ equiv := deviceMount[mnt.UUID]
if equiv == nil {
equiv = mnt
- if mnt.DeviceID != "" {
- deviceMount[mnt.DeviceID] = equiv
- }
+ deviceMount[mnt.UUID] = equiv
}
equivMount[equiv] = append(equivMount[equiv], mnt)
}
go func(mounts []*KeepMount) {
defer wg.Done()
bal.logf("mount %s: retrieve index from %s", mounts[0], mounts[0].KeepService)
- idx, err := mounts[0].KeepService.IndexMount(c, mounts[0].UUID, "")
+ idx, err := mounts[0].KeepService.IndexMount(ctx, c, mounts[0].UUID, bal.ChunkPrefix)
if err != nil {
select {
case errs <- fmt.Errorf("%s: retrieve index: %v", mounts[0], err):
default:
}
+ cancel()
return
}
if len(errs) > 0 {
}(mounts)
}
- // collQ buffers incoming collections so we can start fetching
- // the next page without waiting for the current page to
- // 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
- // process collections much faster than we can retrieve them.)
- wg.Add(1)
- go func() {
- defer wg.Done()
- for coll := range collQ {
- err := bal.addCollection(coll)
- if err != nil {
- select {
- case errs <- err:
- default:
- }
- for range collQ {
- }
- return
- }
- bal.collScanned++
- }
- }()
-
- // Start a goroutine to retrieve all collections from the
- // Arvados database and send them to collQ for processing.
+ // Retrieve all collections from the database and send them to
+ // collQ.
wg.Add(1)
go func() {
defer wg.Done()
- err = EachCollection(c, pageSize,
+ err = EachCollection(ctx, bal.DB, c,
func(coll arvados.Collection) error {
collQ <- coll
if len(errs) > 0 {
case errs <- err:
default:
}
+ cancel()
}
}()
+ // Parse manifests from collQ and pass the block hashes to
+ // BlockStateMap to track desired replication.
+ for i := 0; i < runtime.NumCPU(); i++ {
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ for coll := range collQ {
+ err := bal.addCollection(coll)
+ if err != nil || len(errs) > 0 {
+ select {
+ case errs <- err:
+ default:
+ }
+ cancel()
+ continue
+ }
+ atomic.AddInt64(&bal.collScanned, 1)
+ }
+ }()
+ }
+
wg.Wait()
if len(errs) > 0 {
return <-errs
if coll.ReplicationDesired != nil {
repl = *coll.ReplicationDesired
}
- debugf("%v: %d block x%d", coll.UUID, len(blkids), repl)
- bal.BlockStateMap.IncreaseDesired(coll.StorageClassesDesired, repl, blkids)
+ if bal.ChunkPrefix != "" {
+ // Throw out blocks that don't match the requested
+ // prefix. (We save a bit of GC work here by
+ // preallocating based on each hex digit in
+ // ChunkPrefix reducing the expected size of the
+ // filtered set by ~16x.)
+ filtered := make([]arvados.SizedDigest, 0, len(blkids)>>(4*len(bal.ChunkPrefix)-1))
+ for _, blkid := range blkids {
+ if strings.HasPrefix(string(blkid), bal.ChunkPrefix) {
+ filtered = append(filtered, blkid)
+ }
+ }
+ blkids = filtered
+ }
+ bal.Logger.Debugf("%v: %d blocks x%d", coll.UUID, len(blkids), repl)
+ // Pass pdh to IncreaseDesired only if LostBlocksFile is being
+ // written -- otherwise it's just a waste of memory.
+ pdh := ""
+ if bal.LostBlocksFile != "" {
+ pdh = coll.PortableDataHash
+ }
+ bal.BlockStateMap.IncreaseDesired(pdh, coll.StorageClassesDesired, repl, blkids)
return nil
}
func (bal *Balancer) setupLookupTables() {
bal.serviceRoots = make(map[string]string)
- bal.classes = []string{"default"}
+ bal.classes = defaultClasses
bal.mountsByClass = map[string]map[*KeepMount]bool{"default": {}}
bal.mounts = 0
for _, srv := range bal.KeepServices {
// 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 {
+ 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}
changeNone: "none",
}
+type balancedBlockState struct {
+ needed int
+ unneeded int
+ pulling int
+ unachievable bool
+}
+
type balanceResult struct {
blk *BlockState
blkid arvados.SizedDigest
- have int
- want int
+ lost bool
+ blockState balancedBlockState
classState map[string]balancedBlockState
}
+type slot struct {
+ mnt *KeepMount // never nil
+ repl *Replica // replica already stored here (or nil)
+ want bool // we should pull/leave a replica here
+}
+
// 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) 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
- }
+ bal.Logger.Debugf("balanceBlock: %v %+v", blkid, blk)
// Build a list of all slots (one per mounted volume).
slots := make([]slot, 0, bal.mounts)
// 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
}
// new/remaining replicas uniformly
// across qualifying mounts on a given
// server.
- return rendezvousLess(si.mnt.DeviceID, sj.mnt.DeviceID, blkid)
+ return rendezvousLess(si.mnt.UUID, sj.mnt.UUID, blkid)
}
})
// and returns true if all requirements are met.
trySlot := func(i int) bool {
slot := slots[i]
- if wantMnt[slot.mnt] || wantDev[slot.mnt.DeviceID] {
+ if wantMnt[slot.mnt] || wantDev[slot.mnt.UUID] {
// Already allocated a replica to this
// backend device, possibly on a
// different server.
slots[i].want = true
wantSrv[slot.mnt.KeepService] = true
wantMnt[slot.mnt] = true
- if slot.mnt.DeviceID != "" {
- wantDev[slot.mnt.DeviceID] = true
- }
+ wantDev[slot.mnt.UUID] = true
replWant += slot.mnt.Replication
}
return replProt >= desired && replWant >= desired
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] {
+ if slot.repl != nil && wantDev[slot.mnt.UUID] {
unsafeToDelete[slot.repl.Mtime] = true
}
}
// 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
+ for i, slot := range slots {
+ // Don't trash (1) any replicas of an underreplicated
+ // block, even if they're in the wrong positions, or
+ // (2) any replicas whose Mtimes are identical to
+ // needed replicas (in case we're really seeing the
+ // same copy via different mounts).
+ if slot.repl != nil && (underreplicated || unsafeToDelete[slot.repl.Mtime]) {
+ slots[i].want = true
}
}
- var changes []string
+ classState := make(map[string]balancedBlockState, len(bal.classes))
+ for _, class := range bal.classes {
+ classState[class] = computeBlockState(slots, bal.mountsByClass[class], len(blk.Replicas), blk.Desired[class])
+ }
+ blockState := computeBlockState(slots, nil, len(blk.Replicas), 0)
+
+ // Sort the slots by rendezvous order. This ensures "trash the
+ // first of N replicas with identical timestamps" is
+ // predictable (helpful for testing) and well distributed
+ // across servers.
+ sort.Slice(slots, func(i, j int) bool {
+ si, sj := slots[i], slots[j]
+ if orderi, orderj := srvRendezvous[si.mnt.KeepService], srvRendezvous[sj.mnt.KeepService]; orderi != orderj {
+ return orderi < orderj
+ } else {
+ return rendezvousLess(si.mnt.UUID, sj.mnt.UUID, blkid)
+ }
+ })
+
+ var (
+ lost bool
+ changes []string
+ trashedMtime = make(map[int64]bool, len(slots))
+ )
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 && slot.repl == nil && slot.want && !slot.mnt.ReadOnly:
+ case !slot.want && slot.repl != nil && slot.repl.Mtime < bal.MinMtime:
+ if trashedMtime[slot.repl.Mtime] {
+ // Don't trash multiple replicas with
+ // identical timestamps. If they are
+ // multiple views of the same backing
+ // storage, asking both servers to
+ // trash is redundant and can cause
+ // races (see #20242). If they are
+ // distinct replicas that happen to
+ // have identical timestamps, we'll
+ // get this one on the next sweep.
+ change = changeNone
+ } else {
+ slot.mnt.KeepService.AddTrash(Trash{
+ SizedDigest: blkid,
+ Mtime: slot.repl.Mtime,
+ From: slot.mnt,
+ })
+ change = changeTrash
+ trashedMtime[slot.repl.Mtime] = true
+ }
+ case slot.repl == nil && slot.want && len(blk.Replicas) == 0:
+ lost = true
+ change = changeNone
+ case slot.repl == nil && slot.want && !slot.mnt.ReadOnly:
slot.mnt.KeepService.AddPull(Pull{
SizedDigest: blkid,
From: blk.Replicas[0].KeepMount.KeepService,
}
}
if bal.Dumper != nil {
- bal.Dumper.Printf("%s refs=%d have=%d want=%v %v %v", blkid, blk.RefCount, have, want, blk.Desired, changes)
+ bal.Dumper.Printf("%s refs=%d needed=%d unneeded=%d pulling=%v %v %v", blkid, blk.RefCount, blockState.needed, blockState.unneeded, blockState.pulling, blk.Desired, changes)
}
return balanceResult{
blk: blk,
blkid: blkid,
- have: have,
- want: want,
+ lost: lost,
+ blockState: blockState,
classState: classState,
}
}
+func computeBlockState(slots []slot, onlyCount map[*KeepMount]bool, have, needRepl int) (bbs balancedBlockState) {
+ repl := 0
+ countedDev := map[string]bool{}
+ for _, slot := range slots {
+ if onlyCount != nil && !onlyCount[slot.mnt] {
+ continue
+ }
+ if countedDev[slot.mnt.UUID] {
+ continue
+ }
+ switch {
+ case slot.repl != nil && slot.want:
+ bbs.needed++
+ repl += slot.mnt.Replication
+ case slot.repl != nil && !slot.want:
+ bbs.unneeded++
+ repl += slot.mnt.Replication
+ case slot.repl == nil && slot.want && have > 0:
+ bbs.pulling++
+ repl += slot.mnt.Replication
+ }
+ countedDev[slot.mnt.UUID] = true
+ }
+ if repl < needRepl {
+ bbs.unachievable = true
+ }
+ return
+}
+
type blocksNBytes struct {
replicas int
blocks int
return fmt.Sprintf("%d replicas (%d blocks, %d bytes)", bb.replicas, bb.blocks, bb.bytes)
}
+type replicationStats struct {
+ needed blocksNBytes
+ unneeded blocksNBytes
+ pulling blocksNBytes
+ unachievable blocksNBytes
+}
+
type balancerStats struct {
lost blocksNBytes
overrep blocksNBytes
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) collectStatistics(results <-chan balanceResult) {
var s balancerStats
s.replHistogram = make([]int, 2)
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 {
for class, state := range result.classState {
cs := s.classStats[class]
if state.unachievable {
+ cs.unachievable.replicas++
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.needed > 0 {
+ cs.needed.replicas += state.needed
+ cs.needed.blocks++
+ cs.needed.bytes += bytes * int64(state.needed)
}
- 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)
+ if state.unneeded > 0 {
+ cs.unneeded.replicas += state.unneeded
+ cs.unneeded.blocks++
+ cs.unneeded.bytes += bytes * int64(state.unneeded)
+ }
+ if state.pulling > 0 {
+ cs.pulling.replicas += state.pulling
+ cs.pulling.blocks++
+ cs.pulling.bytes += bytes * int64(state.pulling)
}
s.classStats[class] = cs
}
+ bs := result.blockState
switch {
- case result.have == 0 && result.want > 0:
- s.lost.replicas -= surplus
+ case result.lost:
+ s.lost.replicas++
s.lost.blocks++
- s.lost.bytes += bytes * int64(-surplus)
- case surplus < 0:
- s.underrep.replicas -= surplus
+ s.lost.bytes += bytes
+ fmt.Fprintf(bal.lostBlocks, "%s", strings.SplitN(string(result.blkid), "+", 2)[0])
+ for pdh := range result.blk.Refs {
+ fmt.Fprintf(bal.lostBlocks, " %s", pdh)
+ }
+ fmt.Fprint(bal.lostBlocks, "\n")
+ case bs.pulling > 0:
+ s.underrep.replicas += bs.pulling
+ s.underrep.blocks++
+ s.underrep.bytes += bytes * int64(bs.pulling)
+ case bs.unachievable:
+ s.underrep.replicas++
s.underrep.blocks++
- s.underrep.bytes += bytes * int64(-surplus)
- case surplus > 0 && result.want == 0:
+ s.underrep.bytes += bytes
+ case bs.unneeded > 0 && bs.needed == 0:
+ // Count as "garbage" if all replicas are old
+ // enough to trash, otherwise count as
+ // "unref".
counter := &s.garbage
for _, r := range result.blk.Replicas {
if r.Mtime >= bal.MinMtime {
break
}
}
- counter.replicas += surplus
+ counter.replicas += bs.unneeded
counter.blocks++
- counter.bytes += bytes * int64(surplus)
- case surplus > 0:
- s.overrep.replicas += surplus
+ counter.bytes += bytes * int64(bs.unneeded)
+ case bs.unneeded > 0:
+ s.overrep.replicas += bs.unneeded
s.overrep.blocks++
- s.overrep.bytes += bytes * int64(result.have-result.want)
+ s.overrep.bytes += bytes * int64(bs.unneeded)
default:
- s.justright.replicas += result.want
+ s.justright.replicas += bs.needed
s.justright.blocks++
- s.justright.bytes += bytes * int64(result.want)
+ s.justright.bytes += bytes * int64(bs.needed)
}
- if result.want > 0 {
- s.desired.replicas += result.want
+ if bs.needed > 0 {
+ s.desired.replicas += bs.needed
s.desired.blocks++
- s.desired.bytes += bytes * int64(result.want)
+ s.desired.bytes += bytes * int64(bs.needed)
}
- if result.have > 0 {
- s.current.replicas += result.have
+ if bs.needed+bs.unneeded > 0 {
+ s.current.replicas += bs.needed + bs.unneeded
s.current.blocks++
- s.current.bytes += bytes * int64(result.have)
+ s.current.bytes += bytes * int64(bs.needed+bs.unneeded)
}
- for len(s.replHistogram) <= result.have {
+ for len(s.replHistogram) <= bs.needed+bs.unneeded {
s.replHistogram = append(s.replHistogram, 0)
}
- s.replHistogram[result.have]++
+ s.replHistogram[bs.needed+bs.unneeded]++
}
for _, srv := range bal.KeepServices {
s.pulls += len(srv.ChangeSet.Pulls)
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 needed", class, cs.needed)
+ bal.logf("storage class %q: %s unneeded", class, cs.unneeded)
+ bal.logf("storage class %q: %s pulling", class, cs.pulling)
bal.logf("storage class %q: %s unachievable", class, cs.unachievable)
}
bal.logf("===")
}
func (bal *Balancer) printHistogram(hashColumns int) {
- bal.logf("Replication level distribution (counting N replicas on a single server as N):")
+ bal.logf("Replication level distribution:")
maxCount := 0
for _, count := range bal.stats.replHistogram {
if maxCount < count {
// keepstore servers. This has the effect of increasing replication of
// existing blocks that are either underreplicated or poorly
// distributed according to rendezvous hashing.
-func (bal *Balancer) CommitPulls(c *arvados.Client) error {
+func (bal *Balancer) CommitPulls(ctx context.Context, 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)
+ return srv.CommitPulls(ctx, c)
})
}
// CommitTrash sends the computed lists of trash requests to the
// keepstore servers. This has the effect of deleting blocks that are
// overreplicated or unreferenced.
-func (bal *Balancer) CommitTrash(c *arvados.Client) error {
+func (bal *Balancer) CommitTrash(ctx context.Context, 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)
+ return srv.CommitTrash(ctx, c)
})
}
}
}
+// Log current memory usage: once now, at least once every 10 minutes,
+// and when memory grows by 40% since the last log. Stop when ctx is
+// canceled.
+func (bal *Balancer) reportMemorySize(ctx context.Context) {
+ buf, _ := os.ReadFile("/proc/self/smaps")
+ m := regexp.MustCompile(`\nKernelPageSize:\s*(\d+) kB\n`).FindSubmatch(buf)
+ var pagesize int64
+ if len(m) == 2 {
+ pagesize, _ = strconv.ParseInt(string(m[1]), 10, 64)
+ pagesize <<= 10
+ }
+ if pagesize == 0 {
+ bal.logf("cannot log OS-reported memory size: failed to parse KernelPageSize from /proc/self/smaps")
+ }
+ osstats := func() string {
+ if pagesize == 0 {
+ return ""
+ }
+ buf, _ := os.ReadFile("/proc/self/statm")
+ fields := strings.Split(string(buf), " ")
+ if len(fields) < 2 {
+ return ""
+ }
+ virt, _ := strconv.ParseInt(fields[0], 10, 64)
+ virt *= pagesize
+ res, _ := strconv.ParseInt(fields[1], 10, 64)
+ res *= pagesize
+ if virt == 0 || res == 0 {
+ return ""
+ }
+ return fmt.Sprintf(" virt %d res %d", virt, res)
+ }
+
+ var nextTime time.Time
+ var nextMem uint64
+ const maxInterval = time.Minute * 10
+ const maxIncrease = 1.4
+
+ ticker := time.NewTicker(time.Second)
+ defer ticker.Stop()
+ var memstats runtime.MemStats
+ for ctx.Err() == nil {
+ now := time.Now()
+ runtime.ReadMemStats(&memstats)
+ mem := memstats.StackInuse + memstats.HeapInuse
+ if now.After(nextTime) || mem >= nextMem {
+ bal.logf("heap %d stack %d heapalloc %d%s", memstats.HeapInuse, memstats.StackInuse, memstats.HeapAlloc, osstats())
+ nextMem = uint64(float64(mem) * maxIncrease)
+ nextTime = now.Add(maxInterval)
+ }
+ <-ticker.C
+ }
+}
+
// 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 {