syncthing/vendor/github.com/prometheus/procfs/xfs/xfs.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

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Go

// Copyright 2017 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 xfs provides access to statistics exposed by the XFS filesystem.
package xfs
// Stats contains XFS filesystem runtime statistics, parsed from
// /proc/fs/xfs/stat.
//
// The names and meanings of each statistic were taken from
// http://xfs.org/index.php/Runtime_Stats and xfs_stats.h in the Linux
// kernel source. Most counters are uint32s (same data types used in
// xfs_stats.h), but some of the "extended precision stats" are uint64s.
type Stats struct {
// The name of the filesystem used to source these statistics.
// If empty, this indicates aggregated statistics for all XFS
// filesystems on the host.
Name string
ExtentAllocation ExtentAllocationStats
AllocationBTree BTreeStats
BlockMapping BlockMappingStats
BlockMapBTree BTreeStats
DirectoryOperation DirectoryOperationStats
Transaction TransactionStats
InodeOperation InodeOperationStats
LogOperation LogOperationStats
ReadWrite ReadWriteStats
AttributeOperation AttributeOperationStats
InodeClustering InodeClusteringStats
Vnode VnodeStats
Buffer BufferStats
ExtendedPrecision ExtendedPrecisionStats
}
// ExtentAllocationStats contains statistics regarding XFS extent allocations.
type ExtentAllocationStats struct {
ExtentsAllocated uint32
BlocksAllocated uint32
ExtentsFreed uint32
BlocksFreed uint32
}
// BTreeStats contains statistics regarding an XFS internal B-tree.
type BTreeStats struct {
Lookups uint32
Compares uint32
RecordsInserted uint32
RecordsDeleted uint32
}
// BlockMappingStats contains statistics regarding XFS block maps.
type BlockMappingStats struct {
Reads uint32
Writes uint32
Unmaps uint32
ExtentListInsertions uint32
ExtentListDeletions uint32
ExtentListLookups uint32
ExtentListCompares uint32
}
// DirectoryOperationStats contains statistics regarding XFS directory entries.
type DirectoryOperationStats struct {
Lookups uint32
Creates uint32
Removes uint32
Getdents uint32
}
// TransactionStats contains statistics regarding XFS metadata transactions.
type TransactionStats struct {
Sync uint32
Async uint32
Empty uint32
}
// InodeOperationStats contains statistics regarding XFS inode operations.
type InodeOperationStats struct {
Attempts uint32
Found uint32
Recycle uint32
Missed uint32
Duplicate uint32
Reclaims uint32
AttributeChange uint32
}
// LogOperationStats contains statistics regarding the XFS log buffer.
type LogOperationStats struct {
Writes uint32
Blocks uint32
NoInternalBuffers uint32
Force uint32
ForceSleep uint32
}
// ReadWriteStats contains statistics regarding the number of read and write
// system calls for XFS filesystems.
type ReadWriteStats struct {
Read uint32
Write uint32
}
// AttributeOperationStats contains statistics regarding manipulation of
// XFS extended file attributes.
type AttributeOperationStats struct {
Get uint32
Set uint32
Remove uint32
List uint32
}
// InodeClusteringStats contains statistics regarding XFS inode clustering
// operations.
type InodeClusteringStats struct {
Iflush uint32
Flush uint32
FlushInode uint32
}
// VnodeStats contains statistics regarding XFS vnode operations.
type VnodeStats struct {
Active uint32
Allocate uint32
Get uint32
Hold uint32
Release uint32
Reclaim uint32
Remove uint32
Free uint32
}
// BufferStats contains statistics regarding XFS read/write I/O buffers.
type BufferStats struct {
Get uint32
Create uint32
GetLocked uint32
GetLockedWaited uint32
BusyLocked uint32
MissLocked uint32
PageRetries uint32
PageFound uint32
GetRead uint32
}
// ExtendedPrecisionStats contains high precision counters used to track the
// total number of bytes read, written, or flushed, during XFS operations.
type ExtendedPrecisionStats struct {
FlushBytes uint64
WriteBytes uint64
ReadBytes uint64
}