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sparsehistogram: integer types and timestamp separation (#9014) 

* integer types and timestamp separation

1) unify types to int64. as suggested by beorn. we want to support
   counters going down (resets) even if we plan to create new chunks for
   now, in that case
2) histogram type doesn't know its own timestamp. include it separately
   in appending and iteration

Signed-off-by: Dieter Plaetinck <dieter@grafana.com>

* correction: count and zeroCount to remain unsigned

to make api more resilient and that's what we use in protobuf anyway

Signed-off-by: Dieter Plaetinck <dieter@grafana.com>

* temp hack. Ganesh will fix

Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
This commit is contained in:
Dieter Plaetinck 2021-06-29 16:57:59 +03:00 committed by GitHub
parent fd11a339a7
commit 58917d1b76
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 50 additions and 45 deletions
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1
pkg/histogram/sparse_histogram.go
View File

@ -14,7 +14,6 @@
package histogram
type SparseHistogram struct {
Ts int64
Count, ZeroCount uint64
Sum, ZeroThreshold float64
Schema int32

2
tsdb/chunkenc/chunk.go
View File

@ -73,7 +73,7 @@ type Chunk interface {
// Appender adds sample pairs to a chunk.
type Appender interface {
Append(int64, float64)
AppendHistogram(h histogram.SparseHistogram)
AppendHistogram(t int64, h histogram.SparseHistogram)
}
// Iterator is a simple iterator that can only get the next value.

67
tsdb/chunkenc/histo.go
View File

@ -206,9 +206,10 @@ type histoAppender struct {
posSpans, negSpans []histogram.Span
// for the fields that are tracked as dod's
// note that we expect to handle negative deltas (e.g. resets) by creating new chunks, we still want to support it in general hence signed integer types
t int64
cnt, zcnt uint64
tDelta, cntDelta, zcntDelta uint64
tDelta, cntDelta, zcntDelta int64
posbuckets, negbuckets []int64
posbucketsDelta, negbucketsDelta []int64
@ -260,8 +261,8 @@ func (a *histoAppender) Append(int64, float64) {
// AppendHistogram appends a SparseHistogram to the chunk
// we assume the histogram is properly structured. E.g. that the number pos/neg buckets used corresponds to the number conveyed by the pos/neg span structures
func (a *histoAppender) AppendHistogram(h histogram.SparseHistogram) {
var tDelta, cntDelta, zcntDelta uint64
func (a *histoAppender) AppendHistogram(t int64, h histogram.SparseHistogram) {
var tDelta, cntDelta, zcntDelta int64
num := binary.BigEndian.Uint16(a.b.bytes())
if num == 0 {
@ -273,7 +274,7 @@ func (a *histoAppender) AppendHistogram(h histogram.SparseHistogram) {
a.schema = h.Schema
a.posSpans, a.negSpans = h.PositiveSpans, h.NegativeSpans
putVarint(a.b, a.buf64, h.Ts)
putVarint(a.b, a.buf64, t)
putUvarint(a.b, a.buf64, h.Count)
putUvarint(a.b, a.buf64, h.ZeroCount)
a.b.writeBits(math.Float64bits(h.Sum), 64)
@ -284,16 +285,13 @@ func (a *histoAppender) AppendHistogram(h histogram.SparseHistogram) {
putVarint(a.b, a.buf64, buck)
}
} else if num == 1 {
tDelta = uint64(h.Ts - a.t)
tDelta = t - a.t
cntDelta = int64(h.Count) - int64(a.cnt)
zcntDelta = int64(h.ZeroCount) - int64(a.zcnt)
// WARNING: we assume all counts go up. what guarantee do we have this is true? uint may underflow if not.
cntDelta = h.Count - a.cnt
zcntDelta = h.ZeroCount - a.zcnt
putUvarint(a.b, a.buf64, tDelta)
putUvarint(a.b, a.buf64, cntDelta)
putUvarint(a.b, a.buf64, zcntDelta)
putVarint(a.b, a.buf64, tDelta)
putVarint(a.b, a.buf64, cntDelta)
putVarint(a.b, a.buf64, zcntDelta)
a.writeSumDelta(h.Sum)
@ -308,13 +306,13 @@ func (a *histoAppender) AppendHistogram(h histogram.SparseHistogram) {
a.negbucketsDelta[i] = delta
}
} else {
tDelta = uint64(h.Ts - a.t)
cntDelta = h.Count - a.cnt
zcntDelta = h.ZeroCount - a.zcnt
tDelta = t - a.t
cntDelta = int64(h.Count) - int64(a.cnt)
zcntDelta = int64(h.ZeroCount) - int64(a.zcnt)
tDod := int64(tDelta - a.tDelta)
cntDod := int64(cntDelta - a.cntDelta)
zcntDod := int64(zcntDelta - a.zcntDelta)
tDod := tDelta - a.tDelta
cntDod := cntDelta - a.cntDelta
zcntDod := zcntDelta - a.zcntDelta
putDod(a.b, tDod)
putDod(a.b, cntDod)
@ -338,7 +336,7 @@ func (a *histoAppender) AppendHistogram(h histogram.SparseHistogram) {
binary.BigEndian.PutUint16(a.b.bytes(), num+1)
a.t = h.Ts
a.t = t
a.cnt = h.Count
a.zcnt = h.ZeroCount
a.tDelta = tDelta
@ -399,7 +397,7 @@ type histoIterator struct {
// for the fields that are tracked as dod's
t int64
cnt, zcnt uint64
tDelta, cntDelta, zcntDelta uint64
tDelta, cntDelta, zcntDelta int64
posbuckets, negbuckets []int64
posbucketsDelta, negbucketsDelta []int64
@ -424,9 +422,8 @@ func (it *histoIterator) Seek(t int64) bool {
}
return true
}
func (it *histoIterator) At() (h histogram.SparseHistogram) {
return histogram.SparseHistogram{
Ts: it.t,
func (it *histoIterator) At() (t int64, h histogram.SparseHistogram) {
return it.t, histogram.SparseHistogram{
Count: it.cnt,
ZeroCount: it.zcnt,
Sum: it.sum,
@ -524,7 +521,7 @@ func (it *histoIterator) Next() bool {
}
if it.numRead == 1 {
tDelta, err := binary.ReadUvarint(&it.br)
tDelta, err := binary.ReadVarint(&it.br)
if err != nil {
it.err = err
return false
@ -532,21 +529,21 @@ func (it *histoIterator) Next() bool {
it.tDelta = tDelta
it.t += int64(it.tDelta)
cntDelta, err := binary.ReadUvarint(&it.br)
cntDelta, err := binary.ReadVarint(&it.br)
if err != nil {
it.err = err
return false
}
it.cntDelta = cntDelta
it.cnt += it.cntDelta
it.cnt = uint64(int64(it.cnt) + it.cntDelta)
zcntDelta, err := binary.ReadUvarint(&it.br)
zcntDelta, err := binary.ReadVarint(&it.br)
if err != nil {
it.err = err
return false
}
it.zcntDelta = zcntDelta
it.zcnt += it.zcntDelta
it.zcnt = uint64(int64(it.zcnt) + it.zcntDelta)
ok := it.readSum()
if !ok {
@ -580,22 +577,22 @@ func (it *histoIterator) Next() bool {
if !ok {
return ok
}
it.tDelta = uint64(int64(it.tDelta) + tDod)
it.t += int64(it.tDelta)
it.tDelta = it.tDelta + tDod
it.t += it.tDelta
cntDod, ok := it.readDod()
if !ok {
return ok
}
it.cntDelta = uint64(int64(it.cntDelta) + cntDod)
it.cnt += it.cntDelta
it.cntDelta = it.cntDelta + cntDod
it.cnt = uint64(int64(it.cnt) + it.cntDelta)
zcntDod, ok := it.readDod()
if !ok {
return ok
}
it.zcntDelta = uint64(int64(it.zcntDelta) + zcntDod)
it.zcnt += it.zcntDelta
it.zcntDelta = it.zcntDelta + zcntDod
it.zcnt = uint64(int64(it.zcnt) + it.zcntDelta)
ok = it.readSum()
if !ok {

21
tsdb/chunkenc/histo_test.go
View File

@ -24,12 +24,20 @@ func TestHistoChunkSameBuckets(t *testing.T) {
c := NewHistoChunk()
type res struct {
t int64
h histogram.SparseHistogram
}
// create fresh appender and add the first histogram
app, err := c.Appender()
require.NoError(t, err)
require.Equal(t, c.NumSamples(), 0)
ts := int64(1234567890)
h := histogram.SparseHistogram{
Ts: 1234567890,
Count: 5,
ZeroCount: 2,
Sum: 18.4,
@ -44,11 +52,11 @@ func TestHistoChunkSameBuckets(t *testing.T) {
NegativeBuckets: []int64{},
}
app.AppendHistogram(h)
app.AppendHistogram(ts, h)
require.Equal(t, c.NumSamples(), 1)
exp := []histogram.SparseHistogram{
h,
exp := []res{
{t: ts, h: h},
}
// TODO add an update
@ -66,9 +74,10 @@ func TestHistoChunkSameBuckets(t *testing.T) {
// 1. Expand iterator in simple case.
it1 := c.iterator(nil)
require.NoError(t, it1.Err())
var res1 []histogram.SparseHistogram
var res1 []res
for it1.Next() {
res1 = append(res1, it1.At())
ts, h := it1.At()
res1 = append(res1, res{t: ts, h: h})
}
require.NoError(t, it1.Err())
require.Equal(t, exp, res1)

2
tsdb/chunkenc/xor.go
View File

@ -149,7 +149,7 @@ type xorAppender struct {
trailing uint8
}
func (a *xorAppender) AppendHistogram(h histogram.SparseHistogram) {
func (a *xorAppender) AppendHistogram(t int64, h histogram.SparseHistogram) {
panic("cannot call xorAppender.AppendHistogram().")
}

2
tsdb/head.go
View File

@ -1199,7 +1199,7 @@ func (a *initAppender) AppendHistogram(ref uint64, l labels.Labels, sh histogram
if a.app != nil {
return a.app.AppendHistogram(ref, l, sh)
}
a.head.initTime(sh.Ts)
//a.head.initTime(sh.Ts) FIXME(ganesh)
a.app = a.head.appender()
return a.app.AppendHistogram(ref, l, sh)