prometheus/storage/remote/queue_manager_test.go
Julien Pivotto 4e5b1722b3
Move away from testutil, refactor imports (#8087)
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
2020-10-22 11:00:08 +02:00

749 lines
22 KiB
Go

// Copyright 2013 The Prometheus Authors
// 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 remote
import (
"context"
"fmt"
"io/ioutil"
"math"
"net/url"
"os"
"sort"
"strconv"
"strings"
"sync"
"testing"
"time"
"github.com/go-kit/kit/log"
"github.com/gogo/protobuf/proto"
"github.com/golang/snappy"
"github.com/prometheus/client_golang/prometheus"
client_testutil "github.com/prometheus/client_golang/prometheus/testutil"
common_config "github.com/prometheus/common/config"
"github.com/prometheus/common/model"
"github.com/stretchr/testify/assert"
"go.uber.org/atomic"
"github.com/prometheus/prometheus/config"
"github.com/prometheus/prometheus/pkg/labels"
"github.com/prometheus/prometheus/pkg/timestamp"
"github.com/prometheus/prometheus/prompb"
"github.com/prometheus/prometheus/tsdb/record"
)
const defaultFlushDeadline = 1 * time.Minute
func newHighestTimestampMetric() *maxTimestamp {
return &maxTimestamp{
Gauge: prometheus.NewGauge(prometheus.GaugeOpts{
Namespace: namespace,
Subsystem: subsystem,
Name: "highest_timestamp_in_seconds",
Help: "Highest timestamp that has come into the remote storage via the Appender interface, in seconds since epoch.",
}),
}
}
func TestSampleDelivery(t *testing.T) {
// Let's create an even number of send batches so we don't run into the
// batch timeout case.
n := config.DefaultQueueConfig.MaxSamplesPerSend * 2
samples, series := createTimeseries(n, n)
c := NewTestWriteClient()
c.expectSamples(samples[:len(samples)/2], series)
queueConfig := config.DefaultQueueConfig
queueConfig.BatchSendDeadline = model.Duration(100 * time.Millisecond)
queueConfig.MaxShards = 1
queueConfig.Capacity = len(samples)
queueConfig.MaxSamplesPerSend = len(samples) / 2
dir, err := ioutil.TempDir("", "TestSampleDeliver")
assert.NoError(t, err)
defer func() {
assert.NoError(t, os.RemoveAll(dir))
}()
s := NewStorage(nil, nil, nil, dir, defaultFlushDeadline)
defer s.Close()
writeConfig := config.DefaultRemoteWriteConfig
conf := &config.Config{
GlobalConfig: config.DefaultGlobalConfig,
RemoteWriteConfigs: []*config.RemoteWriteConfig{
&writeConfig,
},
}
// We need to set URL's so that metric creation doesn't panic.
writeConfig.URL = &common_config.URL{
URL: &url.URL{
Host: "http://test-storage.com",
},
}
writeConfig.QueueConfig = queueConfig
assert.NoError(t, s.ApplyConfig(conf))
hash, err := toHash(writeConfig)
assert.NoError(t, err)
qm := s.rws.queues[hash]
qm.SetClient(c)
qm.StoreSeries(series, 0)
qm.Append(samples[:len(samples)/2])
c.waitForExpectedSamples(t)
c.expectSamples(samples[len(samples)/2:], series)
qm.Append(samples[len(samples)/2:])
c.waitForExpectedSamples(t)
}
func TestSampleDeliveryTimeout(t *testing.T) {
// Let's send one less sample than batch size, and wait the timeout duration
n := 9
samples, series := createTimeseries(n, n)
c := NewTestWriteClient()
cfg := config.DefaultQueueConfig
cfg.MaxShards = 1
cfg.BatchSendDeadline = model.Duration(100 * time.Millisecond)
dir, err := ioutil.TempDir("", "TestSampleDeliveryTimeout")
assert.NoError(t, err)
defer func() {
assert.NoError(t, os.RemoveAll(dir))
}()
metrics := newQueueManagerMetrics(nil, "", "")
m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, nil, nil, c, defaultFlushDeadline, newPool(), newHighestTimestampMetric())
m.StoreSeries(series, 0)
m.Start()
defer m.Stop()
// Send the samples twice, waiting for the samples in the meantime.
c.expectSamples(samples, series)
m.Append(samples)
c.waitForExpectedSamples(t)
c.expectSamples(samples, series)
m.Append(samples)
c.waitForExpectedSamples(t)
}
func TestSampleDeliveryOrder(t *testing.T) {
ts := 10
n := config.DefaultQueueConfig.MaxSamplesPerSend * ts
samples := make([]record.RefSample, 0, n)
series := make([]record.RefSeries, 0, n)
for i := 0; i < n; i++ {
name := fmt.Sprintf("test_metric_%d", i%ts)
samples = append(samples, record.RefSample{
Ref: uint64(i),
T: int64(i),
V: float64(i),
})
series = append(series, record.RefSeries{
Ref: uint64(i),
Labels: labels.Labels{labels.Label{Name: "__name__", Value: name}},
})
}
c := NewTestWriteClient()
c.expectSamples(samples, series)
dir, err := ioutil.TempDir("", "TestSampleDeliveryOrder")
assert.NoError(t, err)
defer func() {
assert.NoError(t, os.RemoveAll(dir))
}()
metrics := newQueueManagerMetrics(nil, "", "")
m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), config.DefaultQueueConfig, nil, nil, c, defaultFlushDeadline, newPool(), nil)
m.StoreSeries(series, 0)
m.Start()
defer m.Stop()
// These should be received by the client.
m.Append(samples)
c.waitForExpectedSamples(t)
}
func TestShutdown(t *testing.T) {
deadline := 1 * time.Second
c := NewTestBlockedWriteClient()
dir, err := ioutil.TempDir("", "TestShutdown")
assert.NoError(t, err)
defer func() {
assert.NoError(t, os.RemoveAll(dir))
}()
metrics := newQueueManagerMetrics(nil, "", "")
m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), config.DefaultQueueConfig, nil, nil, c, deadline, newPool(), newHighestTimestampMetric())
n := 2 * config.DefaultQueueConfig.MaxSamplesPerSend
samples, series := createTimeseries(n, n)
m.StoreSeries(series, 0)
m.Start()
// Append blocks to guarantee delivery, so we do it in the background.
go func() {
m.Append(samples)
}()
time.Sleep(100 * time.Millisecond)
// Test to ensure that Stop doesn't block.
start := time.Now()
m.Stop()
// The samples will never be delivered, so duration should
// be at least equal to deadline, otherwise the flush deadline
// was not respected.
duration := time.Since(start)
if duration > time.Duration(deadline+(deadline/10)) {
t.Errorf("Took too long to shutdown: %s > %s", duration, deadline)
}
if duration < time.Duration(deadline) {
t.Errorf("Shutdown occurred before flush deadline: %s < %s", duration, deadline)
}
}
func TestSeriesReset(t *testing.T) {
c := NewTestBlockedWriteClient()
deadline := 5 * time.Second
numSegments := 4
numSeries := 25
dir, err := ioutil.TempDir("", "TestSeriesReset")
assert.NoError(t, err)
defer func() {
assert.NoError(t, os.RemoveAll(dir))
}()
metrics := newQueueManagerMetrics(nil, "", "")
m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), config.DefaultQueueConfig, nil, nil, c, deadline, newPool(), newHighestTimestampMetric())
for i := 0; i < numSegments; i++ {
series := []record.RefSeries{}
for j := 0; j < numSeries; j++ {
series = append(series, record.RefSeries{Ref: uint64((i * 100) + j), Labels: labels.Labels{{Name: "a", Value: "a"}}})
}
m.StoreSeries(series, i)
}
assert.Equal(t, numSegments*numSeries, len(m.seriesLabels))
m.SeriesReset(2)
assert.Equal(t, numSegments*numSeries/2, len(m.seriesLabels))
}
func TestReshard(t *testing.T) {
size := 10 // Make bigger to find more races.
nSeries := 6
nSamples := config.DefaultQueueConfig.Capacity * size
samples, series := createTimeseries(nSamples, nSeries)
c := NewTestWriteClient()
c.expectSamples(samples, series)
cfg := config.DefaultQueueConfig
cfg.MaxShards = 1
dir, err := ioutil.TempDir("", "TestReshard")
assert.NoError(t, err)
defer func() {
assert.NoError(t, os.RemoveAll(dir))
}()
metrics := newQueueManagerMetrics(nil, "", "")
m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, nil, nil, c, defaultFlushDeadline, newPool(), newHighestTimestampMetric())
m.StoreSeries(series, 0)
m.Start()
defer m.Stop()
go func() {
for i := 0; i < len(samples); i += config.DefaultQueueConfig.Capacity {
sent := m.Append(samples[i : i+config.DefaultQueueConfig.Capacity])
assert.True(t, sent, "samples not sent")
time.Sleep(100 * time.Millisecond)
}
}()
for i := 1; i < len(samples)/config.DefaultQueueConfig.Capacity; i++ {
m.shards.stop()
m.shards.start(i)
time.Sleep(100 * time.Millisecond)
}
c.waitForExpectedSamples(t)
}
func TestReshardRaceWithStop(t *testing.T) {
c := NewTestWriteClient()
var m *QueueManager
h := sync.Mutex{}
h.Lock()
go func() {
for {
metrics := newQueueManagerMetrics(nil, "", "")
m = NewQueueManager(metrics, nil, nil, nil, "", newEWMARate(ewmaWeight, shardUpdateDuration), config.DefaultQueueConfig, nil, nil, c, defaultFlushDeadline, newPool(), newHighestTimestampMetric())
m.Start()
h.Unlock()
h.Lock()
m.Stop()
}
}()
for i := 1; i < 100; i++ {
h.Lock()
m.reshardChan <- i
h.Unlock()
}
}
func TestReleaseNoninternedString(t *testing.T) {
metrics := newQueueManagerMetrics(nil, "", "")
c := NewTestWriteClient()
m := NewQueueManager(metrics, nil, nil, nil, "", newEWMARate(ewmaWeight, shardUpdateDuration), config.DefaultQueueConfig, nil, nil, c, defaultFlushDeadline, newPool(), newHighestTimestampMetric())
m.Start()
for i := 1; i < 1000; i++ {
m.StoreSeries([]record.RefSeries{
{
Ref: uint64(i),
Labels: labels.Labels{
labels.Label{
Name: "asdf",
Value: fmt.Sprintf("%d", i),
},
},
},
}, 0)
m.SeriesReset(1)
}
metric := client_testutil.ToFloat64(noReferenceReleases)
assert.True(t, metric == 0, "expected there to be no calls to release for strings that were not already interned: %d", int(metric))
}
func TestShouldReshard(t *testing.T) {
type testcase struct {
startingShards int
samplesIn, samplesOut, lastSendTimestamp int64
expectedToReshard bool
}
cases := []testcase{
{
// Resharding shouldn't take place if the last successful send was > batch send deadline*2 seconds ago.
startingShards: 10,
samplesIn: 1000,
samplesOut: 10,
lastSendTimestamp: time.Now().Unix() - int64(3*time.Duration(config.DefaultQueueConfig.BatchSendDeadline)/time.Second),
expectedToReshard: false,
},
{
startingShards: 5,
samplesIn: 1000,
samplesOut: 10,
lastSendTimestamp: time.Now().Unix(),
expectedToReshard: true,
},
}
for _, c := range cases {
metrics := newQueueManagerMetrics(nil, "", "")
client := NewTestWriteClient()
m := NewQueueManager(metrics, nil, nil, nil, "", newEWMARate(ewmaWeight, shardUpdateDuration), config.DefaultQueueConfig, nil, nil, client, defaultFlushDeadline, newPool(), newHighestTimestampMetric())
m.numShards = c.startingShards
m.samplesIn.incr(c.samplesIn)
m.samplesOut.incr(c.samplesOut)
m.lastSendTimestamp.Store(c.lastSendTimestamp)
m.Start()
desiredShards := m.calculateDesiredShards()
shouldReshard := m.shouldReshard(desiredShards)
m.Stop()
assert.Equal(t, c.expectedToReshard, shouldReshard)
}
}
func createTimeseries(numSamples, numSeries int) ([]record.RefSample, []record.RefSeries) {
samples := make([]record.RefSample, 0, numSamples)
series := make([]record.RefSeries, 0, numSeries)
for i := 0; i < numSeries; i++ {
name := fmt.Sprintf("test_metric_%d", i)
for j := 0; j < numSamples; j++ {
samples = append(samples, record.RefSample{
Ref: uint64(i),
T: int64(j),
V: float64(i),
})
}
series = append(series, record.RefSeries{
Ref: uint64(i),
Labels: labels.Labels{{Name: "__name__", Value: name}},
})
}
return samples, series
}
func getSeriesNameFromRef(r record.RefSeries) string {
for _, l := range r.Labels {
if l.Name == "__name__" {
return l.Value
}
}
return ""
}
type TestWriteClient struct {
receivedSamples map[string][]prompb.Sample
expectedSamples map[string][]prompb.Sample
withWaitGroup bool
wg sync.WaitGroup
mtx sync.Mutex
buf []byte
}
func NewTestWriteClient() *TestWriteClient {
return &TestWriteClient{
withWaitGroup: true,
receivedSamples: map[string][]prompb.Sample{},
expectedSamples: map[string][]prompb.Sample{},
}
}
func (c *TestWriteClient) expectSamples(ss []record.RefSample, series []record.RefSeries) {
if !c.withWaitGroup {
return
}
c.mtx.Lock()
defer c.mtx.Unlock()
c.expectedSamples = map[string][]prompb.Sample{}
c.receivedSamples = map[string][]prompb.Sample{}
for _, s := range ss {
seriesName := getSeriesNameFromRef(series[s.Ref])
c.expectedSamples[seriesName] = append(c.expectedSamples[seriesName], prompb.Sample{
Timestamp: s.T,
Value: s.V,
})
}
c.wg.Add(len(ss))
}
func (c *TestWriteClient) waitForExpectedSamples(tb testing.TB) {
if !c.withWaitGroup {
return
}
c.wg.Wait()
c.mtx.Lock()
defer c.mtx.Unlock()
for ts, expectedSamples := range c.expectedSamples {
assert.Equal(tb, expectedSamples, c.receivedSamples[ts], ts)
}
}
func (c *TestWriteClient) expectSampleCount(numSamples int) {
if !c.withWaitGroup {
return
}
c.mtx.Lock()
defer c.mtx.Unlock()
c.wg.Add(numSamples)
}
func (c *TestWriteClient) waitForExpectedSampleCount() {
if !c.withWaitGroup {
return
}
c.wg.Wait()
}
func (c *TestWriteClient) Store(_ context.Context, req []byte) error {
c.mtx.Lock()
defer c.mtx.Unlock()
// nil buffers are ok for snappy, ignore cast error.
if c.buf != nil {
c.buf = c.buf[:cap(c.buf)]
}
reqBuf, err := snappy.Decode(c.buf, req)
c.buf = reqBuf
if err != nil {
return err
}
var reqProto prompb.WriteRequest
if err := proto.Unmarshal(reqBuf, &reqProto); err != nil {
return err
}
count := 0
for _, ts := range reqProto.Timeseries {
var seriesName string
labels := labelProtosToLabels(ts.Labels)
for _, label := range labels {
if label.Name == "__name__" {
seriesName = label.Value
}
}
for _, sample := range ts.Samples {
count++
c.receivedSamples[seriesName] = append(c.receivedSamples[seriesName], sample)
}
}
if c.withWaitGroup {
c.wg.Add(-count)
}
return nil
}
func (c *TestWriteClient) Name() string {
return "testwriteclient"
}
func (c *TestWriteClient) Endpoint() string {
return "http://test-remote.com/1234"
}
// TestBlockingWriteClient is a queue_manager WriteClient which will block
// on any calls to Store(), until the request's Context is cancelled, at which
// point the `numCalls` property will contain a count of how many times Store()
// was called.
type TestBlockingWriteClient struct {
numCalls atomic.Uint64
}
func NewTestBlockedWriteClient() *TestBlockingWriteClient {
return &TestBlockingWriteClient{}
}
func (c *TestBlockingWriteClient) Store(ctx context.Context, _ []byte) error {
c.numCalls.Inc()
<-ctx.Done()
return nil
}
func (c *TestBlockingWriteClient) NumCalls() uint64 {
return c.numCalls.Load()
}
func (c *TestBlockingWriteClient) Name() string {
return "testblockingwriteclient"
}
func (c *TestBlockingWriteClient) Endpoint() string {
return "http://test-remote-blocking.com/1234"
}
func BenchmarkSampleDelivery(b *testing.B) {
// Let's create an even number of send batches so we don't run into the
// batch timeout case.
n := config.DefaultQueueConfig.MaxSamplesPerSend * 10
samples, series := createTimeseries(n, n)
c := NewTestWriteClient()
cfg := config.DefaultQueueConfig
cfg.BatchSendDeadline = model.Duration(100 * time.Millisecond)
cfg.MaxShards = 1
dir, err := ioutil.TempDir("", "BenchmarkSampleDelivery")
assert.NoError(b, err)
defer os.RemoveAll(dir)
metrics := newQueueManagerMetrics(nil, "", "")
m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, nil, nil, c, defaultFlushDeadline, newPool(), newHighestTimestampMetric())
m.StoreSeries(series, 0)
// These should be received by the client.
m.Start()
defer m.Stop()
b.ResetTimer()
for i := 0; i < b.N; i++ {
c.expectSampleCount(len(samples))
m.Append(samples)
c.waitForExpectedSampleCount()
}
// Do not include shutdown
b.StopTimer()
}
func BenchmarkStartup(b *testing.B) {
dir := os.Getenv("WALDIR")
if dir == "" {
return
}
// Find the second largest segment; we will replay up to this.
// (Second largest as WALWatcher will start tailing the largest).
dirents, err := ioutil.ReadDir(dir)
assert.NoError(b, err)
var segments []int
for _, dirent := range dirents {
if i, err := strconv.Atoi(dirent.Name()); err != nil {
segments = append(segments, i)
}
}
sort.Ints(segments)
logger := log.NewLogfmtLogger(log.NewSyncWriter(os.Stdout))
logger = log.With(logger, "caller", log.DefaultCaller)
for n := 0; n < b.N; n++ {
metrics := newQueueManagerMetrics(nil, "", "")
c := NewTestBlockedWriteClient()
m := NewQueueManager(metrics, nil, nil, logger, dir,
newEWMARate(ewmaWeight, shardUpdateDuration),
config.DefaultQueueConfig, nil, nil, c, 1*time.Minute, newPool(), newHighestTimestampMetric())
m.watcher.SetStartTime(timestamp.Time(math.MaxInt64))
m.watcher.MaxSegment = segments[len(segments)-2]
err := m.watcher.Run()
assert.NoError(b, err)
}
}
func TestProcessExternalLabels(t *testing.T) {
for _, tc := range []struct {
labels labels.Labels
externalLabels labels.Labels
expected labels.Labels
}{
// Test adding labels at the end.
{
labels: labels.Labels{{Name: "a", Value: "b"}},
externalLabels: labels.Labels{{Name: "c", Value: "d"}},
expected: labels.Labels{{Name: "a", Value: "b"}, {Name: "c", Value: "d"}},
},
// Test adding labels at the beginning.
{
labels: labels.Labels{{Name: "c", Value: "d"}},
externalLabels: labels.Labels{{Name: "a", Value: "b"}},
expected: labels.Labels{{Name: "a", Value: "b"}, {Name: "c", Value: "d"}},
},
// Test we don't override existing labels.
{
labels: labels.Labels{{Name: "a", Value: "b"}},
externalLabels: labels.Labels{{Name: "a", Value: "c"}},
expected: labels.Labels{{Name: "a", Value: "b"}},
},
} {
assert.Equal(t, tc.expected, processExternalLabels(tc.labels, tc.externalLabels))
}
}
func TestCalculateDesiredShards(t *testing.T) {
c := NewTestWriteClient()
cfg := config.DefaultQueueConfig
dir, err := ioutil.TempDir("", "TestCalculateDesiredShards")
assert.NoError(t, err)
defer func() {
assert.NoError(t, os.RemoveAll(dir))
}()
metrics := newQueueManagerMetrics(nil, "", "")
samplesIn := newEWMARate(ewmaWeight, shardUpdateDuration)
m := NewQueueManager(metrics, nil, nil, nil, dir, samplesIn, cfg, nil, nil, c, defaultFlushDeadline, newPool(), newHighestTimestampMetric())
// Need to start the queue manager so the proper metrics are initialized.
// However we can stop it right away since we don't need to do any actual
// processing.
m.Start()
m.Stop()
inputRate := int64(50000)
var pendingSamples int64
// Two minute startup, no samples are sent.
startedAt := time.Now().Add(-2 * time.Minute)
// helper function for adding samples.
addSamples := func(s int64, ts time.Duration) {
pendingSamples += s
samplesIn.incr(s)
samplesIn.tick()
m.highestRecvTimestamp.Set(float64(startedAt.Add(ts).Unix()))
}
// helper function for sending samples.
sendSamples := func(s int64, ts time.Duration) {
pendingSamples -= s
m.samplesOut.incr(s)
m.samplesOutDuration.incr(int64(m.numShards) * int64(shardUpdateDuration))
// highest sent is how far back pending samples would be at our input rate.
highestSent := startedAt.Add(ts - time.Duration(pendingSamples/inputRate)*time.Second)
m.metrics.highestSentTimestamp.Set(float64(highestSent.Unix()))
m.lastSendTimestamp.Store(time.Now().Unix())
}
ts := time.Duration(0)
for ; ts < 120*time.Second; ts += shardUpdateDuration {
addSamples(inputRate*int64(shardUpdateDuration/time.Second), ts)
m.numShards = m.calculateDesiredShards()
assert.Equal(t, 1, m.numShards)
}
// Assume 100ms per request, or 10 requests per second per shard.
// Shard calculation should never drop below barely keeping up.
minShards := int(inputRate) / cfg.MaxSamplesPerSend / 10
// This test should never go above 200 shards, that would be more resources than needed.
maxShards := 200
for ; ts < 15*time.Minute; ts += shardUpdateDuration {
sin := inputRate * int64(shardUpdateDuration/time.Second)
addSamples(sin, ts)
sout := int64(m.numShards*cfg.MaxSamplesPerSend) * int64(shardUpdateDuration/(100*time.Millisecond))
// You can't send samples that don't exist so cap at the number of pending samples.
if sout > pendingSamples {
sout = pendingSamples
}
sendSamples(sout, ts)
t.Log("desiredShards", m.numShards, "pendingSamples", pendingSamples)
m.numShards = m.calculateDesiredShards()
assert.True(t, m.numShards >= minShards, "Shards are too low. desiredShards=%d, minShards=%d, t_seconds=%d", m.numShards, minShards, ts/time.Second)
assert.True(t, m.numShards <= maxShards, "Shards are too high. desiredShards=%d, maxShards=%d, t_seconds=%d", m.numShards, maxShards, ts/time.Second)
}
assert.True(t, pendingSamples == 0, "Remote write never caught up, there are still %d pending samples.", pendingSamples)
}
func TestQueueManagerMetrics(t *testing.T) {
reg := prometheus.NewPedanticRegistry()
metrics := newQueueManagerMetrics(reg, "name", "http://localhost:1234")
// Make sure metrics pass linting.
problems, err := client_testutil.GatherAndLint(reg)
assert.NoError(t, err)
assert.Equal(t, 0, len(problems), "Metric linting problems detected: %v", problems)
// Make sure all metrics were unregistered. A failure here means you need
// unregister a metric in `queueManagerMetrics.unregister()`.
metrics.unregister()
err = client_testutil.GatherAndCompare(reg, strings.NewReader(""))
assert.NoError(t, err)
}