syncthing/vendor/github.com/prometheus/procfs/xfrm.go
Jakob Borg 916ec63af6 cmd/stdiscosrv: New discovery server (fixes #4618)
This is a new revision of the discovery server. Relevant changes and
non-changes:

- Protocol towards clients is unchanged.

- Recommended large scale design is still to be deployed nehind nginx (I
  tested, and it's still a lot faster at terminating TLS).

- Database backend is leveldb again, only. It scales enough, is easy to
  setup, and we don't need any backend to take care of.

- Server supports replication. This is a simple TCP channel - protect it
  with a firewall when deploying over the internet. (We deploy this within
  the same datacenter, and with firewall.) Any incoming client announces
  are sent over the replication channel(s) to other peer discosrvs.
  Incoming replication changes are applied to the database as if they came
  from clients, but without the TLS/certificate overhead.

- Metrics are exposed using the prometheus library, when enabled.

- The database values and replication protocol is protobuf, because JSON
  was quite CPU intensive when I tried that and benchmarked it.

- The "Retry-After" value for failed lookups gets slowly increased from
  a default of 120 seconds, by 5 seconds for each failed lookup,
  independently by each discosrv. This lowers the query load over time for
  clients that are never seen. The Retry-After maxes out at 3600 after a
  couple of weeks of this increase. The number of failed lookups is
  stored in the database, now and then (avoiding making each lookup a
  database put).

All in all this means clients can be pointed towards a cluster using
just multiple A / AAAA records to gain both load sharing and redundancy
(if one is down, clients will talk to the remaining ones).

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4648
2018-01-14 08:52:31 +00:00

188 lines
4.8 KiB
Go

// Copyright 2017 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 procfs
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
)
// XfrmStat models the contents of /proc/net/xfrm_stat.
type XfrmStat struct {
// All errors which are not matched by other
XfrmInError int
// No buffer is left
XfrmInBufferError int
// Header Error
XfrmInHdrError int
// No state found
// i.e. either inbound SPI, address, or IPSEC protocol at SA is wrong
XfrmInNoStates int
// Transformation protocol specific error
// e.g. SA Key is wrong
XfrmInStateProtoError int
// Transformation mode specific error
XfrmInStateModeError int
// Sequence error
// e.g. sequence number is out of window
XfrmInStateSeqError int
// State is expired
XfrmInStateExpired int
// State has mismatch option
// e.g. UDP encapsulation type is mismatched
XfrmInStateMismatch int
// State is invalid
XfrmInStateInvalid int
// No matching template for states
// e.g. Inbound SAs are correct but SP rule is wrong
XfrmInTmplMismatch int
// No policy is found for states
// e.g. Inbound SAs are correct but no SP is found
XfrmInNoPols int
// Policy discards
XfrmInPolBlock int
// Policy error
XfrmInPolError int
// All errors which are not matched by others
XfrmOutError int
// Bundle generation error
XfrmOutBundleGenError int
// Bundle check error
XfrmOutBundleCheckError int
// No state was found
XfrmOutNoStates int
// Transformation protocol specific error
XfrmOutStateProtoError int
// Transportation mode specific error
XfrmOutStateModeError int
// Sequence error
// i.e sequence number overflow
XfrmOutStateSeqError int
// State is expired
XfrmOutStateExpired int
// Policy discads
XfrmOutPolBlock int
// Policy is dead
XfrmOutPolDead int
// Policy Error
XfrmOutPolError int
XfrmFwdHdrError int
XfrmOutStateInvalid int
XfrmAcquireError int
}
// NewXfrmStat reads the xfrm_stat statistics.
func NewXfrmStat() (XfrmStat, error) {
fs, err := NewFS(DefaultMountPoint)
if err != nil {
return XfrmStat{}, err
}
return fs.NewXfrmStat()
}
// NewXfrmStat reads the xfrm_stat statistics from the 'proc' filesystem.
func (fs FS) NewXfrmStat() (XfrmStat, error) {
file, err := os.Open(fs.Path("net/xfrm_stat"))
if err != nil {
return XfrmStat{}, err
}
defer file.Close()
var (
x = XfrmStat{}
s = bufio.NewScanner(file)
)
for s.Scan() {
fields := strings.Fields(s.Text())
if len(fields) != 2 {
return XfrmStat{}, fmt.Errorf(
"couldnt parse %s line %s", file.Name(), s.Text())
}
name := fields[0]
value, err := strconv.Atoi(fields[1])
if err != nil {
return XfrmStat{}, err
}
switch name {
case "XfrmInError":
x.XfrmInError = value
case "XfrmInBufferError":
x.XfrmInBufferError = value
case "XfrmInHdrError":
x.XfrmInHdrError = value
case "XfrmInNoStates":
x.XfrmInNoStates = value
case "XfrmInStateProtoError":
x.XfrmInStateProtoError = value
case "XfrmInStateModeError":
x.XfrmInStateModeError = value
case "XfrmInStateSeqError":
x.XfrmInStateSeqError = value
case "XfrmInStateExpired":
x.XfrmInStateExpired = value
case "XfrmInStateInvalid":
x.XfrmInStateInvalid = value
case "XfrmInTmplMismatch":
x.XfrmInTmplMismatch = value
case "XfrmInNoPols":
x.XfrmInNoPols = value
case "XfrmInPolBlock":
x.XfrmInPolBlock = value
case "XfrmInPolError":
x.XfrmInPolError = value
case "XfrmOutError":
x.XfrmOutError = value
case "XfrmInStateMismatch":
x.XfrmInStateMismatch = value
case "XfrmOutBundleGenError":
x.XfrmOutBundleGenError = value
case "XfrmOutBundleCheckError":
x.XfrmOutBundleCheckError = value
case "XfrmOutNoStates":
x.XfrmOutNoStates = value
case "XfrmOutStateProtoError":
x.XfrmOutStateProtoError = value
case "XfrmOutStateModeError":
x.XfrmOutStateModeError = value
case "XfrmOutStateSeqError":
x.XfrmOutStateSeqError = value
case "XfrmOutStateExpired":
x.XfrmOutStateExpired = value
case "XfrmOutPolBlock":
x.XfrmOutPolBlock = value
case "XfrmOutPolDead":
x.XfrmOutPolDead = value
case "XfrmOutPolError":
x.XfrmOutPolError = value
case "XfrmFwdHdrError":
x.XfrmFwdHdrError = value
case "XfrmOutStateInvalid":
x.XfrmOutStateInvalid = value
case "XfrmAcquireError":
x.XfrmAcquireError = value
}
}
return x, s.Err()
}