mirror of
https://github.com/prometheus/prometheus
synced 2024-12-25 07:52:28 +00:00
72a9f7fee9
* share tsdb db locker code with agent Closes #9616 Signed-off-by: Robert Fratto <robertfratto@gmail.com> * add flag to disable lockfile for agent Signed-off-by: Robert Fratto <robertfratto@gmail.com> * use agentOnlySetting instead of PreAction Signed-off-by: Robert Fratto <robertfratto@gmail.com> * tsdb: address review feedback 1. Rename Locker to DirLocker 2. Move DirLocker to tsdb/tsdbutil 3. Name metric using fmt.Sprintf 4. Refine error checking in DirLocker test Signed-off-by: Robert Fratto <robertfratto@gmail.com> * tsdb: create test utilities to assert expected DirLocker behavior Signed-off-by: Robert Fratto <robertfratto@gmail.com> * tsdb/tsdbutil: fix lint errors Signed-off-by: Robert Fratto <robertfratto@gmail.com> * tsdb/agent: fix windows test failure Use new DB variable instead of overriding the old one. Signed-off-by: Robert Fratto <robertfratto@gmail.com>
105 lines
2.6 KiB
Go
105 lines
2.6 KiB
Go
// Copyright 2021 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 tsdbutil
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"path/filepath"
|
|
|
|
"github.com/go-kit/log"
|
|
"github.com/go-kit/log/level"
|
|
"github.com/pkg/errors"
|
|
"github.com/prometheus/client_golang/prometheus"
|
|
|
|
tsdb_errors "github.com/prometheus/prometheus/tsdb/errors"
|
|
"github.com/prometheus/prometheus/tsdb/fileutil"
|
|
)
|
|
|
|
const (
|
|
lockfileDisabled = -1
|
|
lockfileReplaced = 0
|
|
lockfileCreatedCleanly = 1
|
|
)
|
|
|
|
type DirLocker struct {
|
|
logger log.Logger
|
|
|
|
createdCleanly prometheus.Gauge
|
|
|
|
releaser fileutil.Releaser
|
|
path string
|
|
}
|
|
|
|
// NewDirLocker creates a DirLocker that can obtain an exclusive lock on dir.
|
|
func NewDirLocker(dir, subsystem string, l log.Logger, r prometheus.Registerer) (*DirLocker, error) {
|
|
lock := &DirLocker{
|
|
logger: l,
|
|
createdCleanly: prometheus.NewGauge(prometheus.GaugeOpts{
|
|
Name: fmt.Sprintf("prometheus_%s_clean_start", subsystem),
|
|
Help: "-1: lockfile is disabled. 0: a lockfile from a previous execution was replaced. 1: lockfile creation was clean",
|
|
}),
|
|
}
|
|
|
|
if r != nil {
|
|
r.MustRegister(lock.createdCleanly)
|
|
}
|
|
|
|
lock.createdCleanly.Set(lockfileDisabled)
|
|
|
|
absdir, err := filepath.Abs(dir)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
lock.path = filepath.Join(absdir, "lock")
|
|
|
|
return lock, nil
|
|
}
|
|
|
|
// Lock obtains the lock on the locker directory.
|
|
func (l *DirLocker) Lock() error {
|
|
if l.releaser != nil {
|
|
return errors.New("DB lock already obtained")
|
|
}
|
|
|
|
if _, err := os.Stat(l.path); err == nil {
|
|
level.Warn(l.logger).Log("msg", "A lockfile from a previous execution already existed. It was replaced", "file", l.path)
|
|
|
|
l.createdCleanly.Set(lockfileReplaced)
|
|
} else {
|
|
l.createdCleanly.Set(lockfileCreatedCleanly)
|
|
}
|
|
|
|
lockf, _, err := fileutil.Flock(l.path)
|
|
if err != nil {
|
|
return errors.Wrap(err, "lock DB directory")
|
|
}
|
|
l.releaser = lockf
|
|
return nil
|
|
}
|
|
|
|
// Release releases the lock. No-op if the lock is not held.
|
|
func (l *DirLocker) Release() error {
|
|
if l.releaser == nil {
|
|
return nil
|
|
}
|
|
|
|
errs := tsdb_errors.NewMulti()
|
|
errs.Add(l.releaser.Release())
|
|
errs.Add(os.Remove(l.path))
|
|
|
|
l.releaser = nil
|
|
return errs.Err()
|
|
}
|