mirror of
https://github.com/prometheus/prometheus.git
synced 2025-02-02 08:31:11 -08:00
So far we've been using Go's native time.Time for anything related to sample timestamps. Since the range of time.Time is much bigger than what we need, this has created two problems: - there could be time.Time values which were out of the range/precision of the time type that we persist to disk, therefore causing incorrectly ordered keys. One bug caused by this was: https://github.com/prometheus/prometheus/issues/367 It would be good to use a timestamp type that's more closely aligned with what the underlying storage supports. - sizeof(time.Time) is 192, while Prometheus should be ok with a single 64-bit Unix timestamp (possibly even a 32-bit one). Since we store samples in large numbers, this seriously affects memory usage. Furthermore, copying/working with the data will be faster if it's smaller. *MEMORY USAGE RESULTS* Initial memory usage comparisons for a running Prometheus with 1 timeseries and 100,000 samples show roughly a 13% decrease in total (VIRT) memory usage. In my tests, this advantage for some reason decreased a bit the more samples the timeseries had (to 5-7% for millions of samples). This I can't fully explain, but perhaps garbage collection issues were involved. *WHEN TO USE THE NEW TIMESTAMP TYPE* The new clientmodel.Timestamp type should be used whenever time calculations are either directly or indirectly related to sample timestamps. For example: - the timestamp of a sample itself - all kinds of watermarks - anything that may become or is compared to a sample timestamp (like the timestamp passed into Target.Scrape()). When to still use time.Time: - for measuring durations/times not related to sample timestamps, like duration telemetry exporting, timers that indicate how frequently to execute some action, etc. *NOTE ON OPERATOR OPTIMIZATION TESTS* We don't use operator optimization code anymore, but it still lives in the code as dead code. It still has tests, but I couldn't get all of them to pass with the new timestamp format. I commented out the failing cases for now, but we should probably remove the dead code soon. I just didn't want to do that in the same change as this. Change-Id: I821787414b0debe85c9fffaeb57abd453727af0f
189 lines
4.4 KiB
Go
189 lines
4.4 KiB
Go
// Copyright 2013 Prometheus Team
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package metric
|
|
|
|
import (
|
|
"testing"
|
|
"time"
|
|
|
|
clientmodel "github.com/prometheus/client_golang/model"
|
|
|
|
"github.com/prometheus/prometheus/utility/test"
|
|
)
|
|
|
|
func testBuilder(t test.Tester) {
|
|
type atTime struct {
|
|
fingerprint string
|
|
time clientmodel.Timestamp
|
|
}
|
|
|
|
type atInterval struct {
|
|
fingerprint string
|
|
from clientmodel.Timestamp
|
|
through clientmodel.Timestamp
|
|
interval time.Duration
|
|
}
|
|
|
|
type atRange struct {
|
|
fingerprint string
|
|
from clientmodel.Timestamp
|
|
through clientmodel.Timestamp
|
|
}
|
|
|
|
type in struct {
|
|
atTimes []atTime
|
|
atIntervals []atInterval
|
|
atRanges []atRange
|
|
}
|
|
|
|
type out []struct {
|
|
fingerprint string
|
|
operations ops
|
|
}
|
|
|
|
var scenarios = []struct {
|
|
in in
|
|
out out
|
|
}{
|
|
// Ensure that the fingerprint is sorted in proper order.
|
|
{
|
|
in: in{
|
|
atTimes: []atTime{
|
|
{
|
|
fingerprint: "0000000000000001111-a-4-a",
|
|
time: clientmodel.TimestampFromUnix(100),
|
|
},
|
|
{
|
|
fingerprint: "0000000000000000000-a-4-a",
|
|
time: clientmodel.TimestampFromUnix(100),
|
|
},
|
|
},
|
|
},
|
|
out: out{
|
|
{
|
|
fingerprint: "00000000000000000000-a-4-a",
|
|
},
|
|
{
|
|
fingerprint: "00000000000000001111-a-4-a",
|
|
},
|
|
},
|
|
},
|
|
// // Ensure that the fingerprint-timestamp pairs are sorted in proper order.
|
|
{
|
|
in: in{
|
|
atTimes: []atTime{
|
|
{
|
|
fingerprint: "1111-a-4-a",
|
|
time: clientmodel.TimestampFromUnix(100),
|
|
},
|
|
{
|
|
fingerprint: "1111-a-4-a",
|
|
time: clientmodel.TimestampFromUnix(200),
|
|
},
|
|
{
|
|
fingerprint: "0-a-4-a",
|
|
time: clientmodel.TimestampFromUnix(100),
|
|
},
|
|
{
|
|
fingerprint: "0-a-4-a",
|
|
time: clientmodel.TimestampFromUnix(0),
|
|
},
|
|
},
|
|
},
|
|
out: out{
|
|
{
|
|
fingerprint: "00000000000000000000-a-4-a",
|
|
},
|
|
{
|
|
fingerprint: "00000000000000001111-a-4-a",
|
|
},
|
|
},
|
|
},
|
|
// Ensure grouping of operations
|
|
{
|
|
in: in{
|
|
atTimes: []atTime{
|
|
{
|
|
fingerprint: "1111-a-4-a",
|
|
time: clientmodel.TimestampFromUnix(100),
|
|
},
|
|
},
|
|
atRanges: []atRange{
|
|
{
|
|
fingerprint: "1111-a-4-a",
|
|
from: clientmodel.TimestampFromUnix(100),
|
|
through: clientmodel.TimestampFromUnix(1000),
|
|
},
|
|
{
|
|
fingerprint: "1111-a-4-a",
|
|
from: clientmodel.TimestampFromUnix(100),
|
|
through: clientmodel.TimestampFromUnix(9000),
|
|
},
|
|
},
|
|
},
|
|
out: out{
|
|
{
|
|
fingerprint: "00000000000000001111-a-4-a",
|
|
},
|
|
},
|
|
},
|
|
}
|
|
|
|
for i, scenario := range scenarios {
|
|
builder := viewRequestBuilder{
|
|
operations: map[clientmodel.Fingerprint]ops{},
|
|
}
|
|
|
|
for _, atTime := range scenario.in.atTimes {
|
|
fingerprint := &clientmodel.Fingerprint{}
|
|
fingerprint.LoadFromString(atTime.fingerprint)
|
|
builder.GetMetricAtTime(fingerprint, atTime.time)
|
|
}
|
|
|
|
for _, atInterval := range scenario.in.atIntervals {
|
|
fingerprint := &clientmodel.Fingerprint{}
|
|
fingerprint.LoadFromString(atInterval.fingerprint)
|
|
builder.GetMetricAtInterval(fingerprint, atInterval.from, atInterval.through, atInterval.interval)
|
|
}
|
|
|
|
for _, atRange := range scenario.in.atRanges {
|
|
fingerprint := &clientmodel.Fingerprint{}
|
|
fingerprint.LoadFromString(atRange.fingerprint)
|
|
builder.GetMetricRange(fingerprint, atRange.from, atRange.through)
|
|
}
|
|
|
|
jobs := builder.ScanJobs()
|
|
|
|
if len(scenario.out) != len(jobs) {
|
|
t.Fatalf("%d. expected job length of %d, got %d", i, len(scenario.out), len(jobs))
|
|
}
|
|
|
|
for j, job := range scenario.out {
|
|
if jobs[j].fingerprint.String() != job.fingerprint {
|
|
t.Fatalf("%d.%d. expected fingerprint %s, got %s", i, j, job.fingerprint, jobs[j].fingerprint)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func TestBuilder(t *testing.T) {
|
|
testBuilder(t)
|
|
}
|
|
|
|
func BenchmarkBuilder(b *testing.B) {
|
|
for i := 0; i < b.N; i++ {
|
|
testBuilder(b)
|
|
}
|
|
}
|