fix(influxd): update xxhash, avoid stringtoslicebyte in cache (#578)

* fix(influxd): update xxhash, avoid stringtoslicebyte in cache

This commit does 3 things:

* it updates xxhash from v1 to v2; v2 includes a assembly arm version of
  Sum64
* it changes the cache storer to write with a string key instead of a
  byte slice. The cache only reads the key which WriteMulti already has
as a string so we can avoid a host of allocations when converting back
and forth from immutable strings to mutable byte slices. This includes
updating the cache ring and ring partition to write with a string key
* it updates the xxhash for finding the cache ring partition to use
Sum64String which uses unsafe pointers to directly use a string as a
byte slice since it only reads the string. Note: this now uses an
assembly version because of the v2 xxhash update. Go 1.22 included new
compiler ability to recognize calls of Method([]byte(myString)) and not
make a copy but from looking at the call sites, I'm not sure the
compiler would recognize it as the conversion to a byte slice was
happening several calls earlier.

That's what this change set does. If we are uncomfortable with any of
these, we can do fewer of them (for example, not upgrade xxhash; and/or
not use the specialized Sum64String, etc).

For the performance issue in maz-rr, I see converting string keys to
byte slices taking between 3-5% of cpu usage on both the primary and
secondary. So while this pr doesn't address directly the increased cpu
usage on the secondary, it makes cpu usage less on both which still
feels like a win. I believe these changes are easier to review that
switching to a byte slice pool that is likely needed in other places as
the compiler provides nearly all of the correctness checks we need (we
are relying also on xxhash v2 being correct).

* helps #550

* chore: fix tests/lint

* chore: don't use assembly version; should inline

This 2 line change causes xxhash to use a purego Sum64 implementation
which allows the compiler to see that Sum64 only read the byte slice
input which them means is can skip the string to byte slice allocation
and since it can skip that, it should inline all the calls to
getPartitionStringKey and Sum64 avoiding 1 call to Sum64String which
isn't inlined.

* chore: update ci build file

the ci build doesn't use the make file!!!

* chore: revert "chore: update ci build file"

This reverts commit 94be66fde03e0bbe18004aab25c0e19051406de2.

* chore: revert "chore: don't use assembly version; should inline"

This reverts commit 67d8d06c02e17e91ba643a2991e30a49308a5283.

(cherry picked from commit 1d334c679ca025645ed93518b7832ae676499cd2)

go.mod

@@ -14,7 +14,7 @@ require (
 	github.com/benbjohnson/clock v0.0.0-20161215174838-7dc76406b6d3
 	github.com/benbjohnson/tmpl v1.0.0
 	github.com/buger/jsonparser v1.1.1
-	github.com/cespare/xxhash v1.1.0
+	github.com/cespare/xxhash/v2 v2.3.0
 	github.com/davecgh/go-spew v1.1.1
 	github.com/dgryski/go-bitstream v0.0.0-20180413035011-3522498ce2c8
 	github.com/dustin/go-humanize v1.0.1
@@ -130,7 +130,6 @@ require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/bonitoo-io/go-sql-bigquery v0.3.4-1.4.0 // indirect
 	github.com/cenkalti/backoff/v4 v4.2.0 // indirect
-	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/containerd/containerd v1.6.18 // indirect
 	github.com/danieljoos/wincred v1.2.1 // indirect
 	github.com/deepmap/oapi-codegen v1.6.0 // indirect

pkg/bloom/bloom.go

@@ -12,7 +12,7 @@ import (
 	"fmt"
 	"math"
 
-	"github.com/cespare/xxhash"
+	"github.com/cespare/xxhash/v2"
 )
 
 // Filter represents a bloom filter.

pkg/estimator/hll/hll.go

@@ -22,7 +22,7 @@ import (
 	"sort"
 	"unsafe"
 
-	"github.com/cespare/xxhash"
+	"github.com/cespare/xxhash/v2"
 	"github.com/influxdata/influxdb/v2/pkg/estimator"
 )
 

pkg/rhh/rhh.go

@@ -7,7 +7,7 @@ import (
 	"sort"
 	"time"
 
-	"github.com/cespare/xxhash"
+	"github.com/cespare/xxhash/v2"
 	"github.com/prometheus/client_golang/prometheus"
 )
 

task/backend/scheduler/treescheduler.go

@@ -8,7 +8,7 @@ import (
 	"time"
 
 	"github.com/benbjohnson/clock"
-	"github.com/cespare/xxhash"
+	"github.com/cespare/xxhash/v2"
 	"github.com/google/btree"
 )
 

tsdb/engine/tsm1/cache.go

@@ -147,7 +147,7 @@ func (e *entry) InfluxQLType() (influxql.DataType, error) {
 // storer is the interface that descibes a cache's store.
 type storer interface {
 	entry(key []byte) *entry                        // Get an entry by its key.
-	write(key []byte, values Values) (bool, error)  // Write an entry to the store.
+	write(key string, values Values) (bool, error)  // Write an entry to the store.
 	remove(key []byte)                              // Remove an entry from the store.
 	keys(sorted bool) [][]byte                      // Return an optionally sorted slice of entry keys.
 	apply(f func([]byte, *entry) error) error       // Apply f to all entries in the store in parallel.
@@ -340,7 +340,7 @@ func (c *Cache) WriteMulti(values map[string][]Value) error {
 	// We'll optimistically set size here, and then decrement it for write errors.
 	c.increaseSize(addedSize)
 	for k, v := range values {
-		newKey, err := store.write([]byte(k), v)
+		newKey, err := store.write(k, v)
 		if err != nil {
 			// The write failed, hold onto the error and adjust the size delta.
 			werr = err
@@ -797,7 +797,7 @@ func valueType(v Value) byte {
 type emptyStore struct{}
 
 func (e emptyStore) entry(key []byte) *entry                        { return nil }
-func (e emptyStore) write(key []byte, values Values) (bool, error)  { return false, nil }
+func (e emptyStore) write(key string, values Values) (bool, error)  { return false, nil }
 func (e emptyStore) remove(key []byte)                              {}
 func (e emptyStore) keys(sorted bool) [][]byte                      { return nil }
 func (e emptyStore) apply(f func([]byte, *entry) error) error       { return nil }

tsdb/engine/tsm1/cache_test.go

@@ -1,7 +1,6 @@
 package tsm1
 
 import (
-	"bytes"
 	"errors"
 	"fmt"
 	"math"
@@ -80,8 +79,8 @@ func TestCache_WriteMulti_Stats(t *testing.T) {
 	c.init()
 	c.store = ms
 
-	ms.writef = func(key []byte, v Values) (bool, error) {
-		if bytes.Equal(key, []byte("foo")) {
+	ms.writef = func(key string, v Values) (bool, error) {
+		if key == "foo" {
 			return false, errors.New("write failed")
 		}
 		return true, nil
@@ -811,7 +810,7 @@ func mustMarshalEntry(entry WALEntry) (WalEntryType, []byte) {
 // Cache's storer implementation.
 type TestStore struct {
 	entryf       func(key []byte) *entry
-	writef       func(key []byte, values Values) (bool, error)
+	writef       func(key string, values Values) (bool, error)
 	removef      func(key []byte)
 	keysf        func(sorted bool) [][]byte
 	applyf       func(f func([]byte, *entry) error) error
@@ -823,7 +822,7 @@ type TestStore struct {
 
 func NewTestStore() *TestStore                                      { return &TestStore{} }
 func (s *TestStore) entry(key []byte) *entry                        { return s.entryf(key) }
-func (s *TestStore) write(key []byte, values Values) (bool, error)  { return s.writef(key, values) }
+func (s *TestStore) write(key string, values Values) (bool, error)  { return s.writef(key, values) }
 func (s *TestStore) remove(key []byte)                              { s.removef(key) }
 func (s *TestStore) keys(sorted bool) [][]byte                      { return s.keysf(sorted) }
 func (s *TestStore) apply(f func([]byte, *entry) error) error       { return s.applyf(f) }

tsdb/engine/tsm1/ring.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"sync"
 
-	"github.com/cespare/xxhash"
+	"github.com/cespare/xxhash/v2"
 	"github.com/influxdata/influxdb/v2/pkg/bytesutil"
 )
 
@@ -80,6 +80,12 @@ func (r *ring) getPartition(key []byte) *partition {
 	return r.partitions[int(xxhash.Sum64(key)%uint64(len(r.partitions)))]
 }
 
+// getPartition retrieves the hash ring partition associated with the provided
+// key, as a string, which can be faster if you already have a string as this is read only
+func (r *ring) getPartitionStringKey(key string) *partition {
+	return r.partitions[int(xxhash.Sum64String(key)%uint64(len(r.partitions)))]
+}
+
 // entry returns the entry for the given key.
 // entry is safe for use by multiple goroutines.
 func (r *ring) entry(key []byte) *entry {
@@ -89,8 +95,8 @@ func (r *ring) entry(key []byte) *entry {
 // write writes values to the entry in the ring's partition associated with key.
 // If no entry exists for the key then one will be created.
 // write is safe for use by multiple goroutines.
-func (r *ring) write(key []byte, values Values) (bool, error) {
-	return r.getPartition(key).write(key, values)
+func (r *ring) write(key string, values Values) (bool, error) {
+	return r.getPartitionStringKey(key).write(key, values)
 }
 
 // remove deletes the entry for the given key.
@@ -218,9 +224,9 @@ func (p *partition) entry(key []byte) *entry {
 // write writes the values to the entry in the partition, creating the entry
 // if it does not exist.
 // write is safe for use by multiple goroutines.
-func (p *partition) write(key []byte, values Values) (bool, error) {
+func (p *partition) write(key string, values Values) (bool, error) {
 	p.mu.RLock()
-	e := p.store[string(key)]
+	e := p.store[key]
 	p.mu.RUnlock()
 	if e != nil {
 		// Hot path.
@@ -231,7 +237,7 @@ func (p *partition) write(key []byte, values Values) (bool, error) {
 	defer p.mu.Unlock()
 
 	// Check again.
-	if e = p.store[string(key)]; e != nil {
+	if e = p.store[key]; e != nil {
 		return false, e.add(values)
 	}
 
@@ -241,7 +247,7 @@ func (p *partition) write(key []byte, values Values) (bool, error) {
 		return false, err
 	}
 
-	p.store[string(key)] = e
+	p.store[key] = e
 	return true, nil
 }
 

tsdb/engine/tsm1/ring_test.go

@@ -51,7 +51,7 @@ var strSliceRes [][]byte
 func benchmarkRingkeys(b *testing.B, r *ring, keys int) {
 	// Add some keys
 	for i := 0; i < keys; i++ {
-		r.write([]byte(fmt.Sprintf("cpu,host=server-%d value=1", i)), Values([]Value{
+		r.write(fmt.Sprintf("cpu,host=server-%d value=1", i), Values([]Value{
 			IntegerValue{
 				unixnano: 1,
 				value:    int64(i),
@@ -77,7 +77,7 @@ func benchmarkRingGetPartition(b *testing.B, r *ring, keys int) {
 	// Add some keys
 	for i := 0; i < keys; i++ {
 		vals[i] = []byte(fmt.Sprintf("cpu,host=server-%d field1=value1,field2=value2,field4=value4,field5=value5,field6=value6,field7=value7,field8=value1,field9=value2,field10=value4,field11=value5,field12=value6,field13=value7", i))
-		r.write([]byte(fmt.Sprintf("cpu,host=server-%d value=1", i)), Values([]Value{
+		r.write(fmt.Sprintf("cpu,host=server-%d value=1", i), Values([]Value{
 			IntegerValue{
 				unixnano: 1,
 				value:    int64(i),
@@ -109,7 +109,7 @@ func benchmarkRingWrite(b *testing.B, r *ring, n int) {
 			go func() {
 				defer wg.Done()
 				for j := 0; j < n; j++ {
-					if _, err := r.write([]byte(fmt.Sprintf("cpu,host=server-%d value=1", j)), Values{}); err != nil {
+					if _, err := r.write(fmt.Sprintf("cpu,host=server-%d value=1", j), Values{}); err != nil {
 						errC <- err
 					}
 				}

tsdb/index/tsi1/index.go

@@ -13,7 +13,7 @@ import (
 	"time"
 	"unsafe"
 
-	"github.com/cespare/xxhash"
+	"github.com/cespare/xxhash/v2"
 	"github.com/influxdata/influxdb/v2/models"
 	"github.com/influxdata/influxdb/v2/pkg/estimator"
 	"github.com/influxdata/influxdb/v2/pkg/estimator/hll"

tsdb/series_file.go

@@ -11,7 +11,7 @@ import (
 	"sort"
 	"sync"
 
-	"github.com/cespare/xxhash"
+	"github.com/cespare/xxhash/v2"
 	"github.com/influxdata/influxdb/v2/models"
 	"github.com/influxdata/influxdb/v2/pkg/binaryutil"
 	"github.com/influxdata/influxdb/v2/pkg/limiter"