slab

README

Slab Input Plugin

This plugin collects details on how much memory each entry in Slab cache is consuming. For example, it collects the consumption of kmalloc-1024 and xfs_inode. Since this information is obtained by parsing /proc/slabinfo file, only Linux is supported. The specification of /proc/slabinfo has not changed since Linux v2.6.12 (April 2005), so it can be regarded as sufficiently stable. The memory usage is equivalent to the CACHE_SIZE column of slabtop command. If the HOST_PROC environment variable is set, Telegraf will use its value instead of /proc

Note: /proc/slabinfo is usually restricted to read as root user. Make sure telegraf can execute sudo without password.

Global configuration options

In addition to the plugin-specific configuration settings, plugins support additional global and plugin configuration settings. These settings are used to modify metrics, tags, and field or create aliases and configure ordering, etc. See the CONFIGURATION.md for more details.

Configuration

# Get slab statistics from procfs
# This plugin ONLY supports Linux
[[inputs.slab]]
  # no configuration - please see the plugin's README for steps to configure
  # sudo properly

Sudo configuration

Since the slabinfo file is only readable by root, the plugin runs sudo /bin/cat to read the file.

Sudo can be configured to allow telegraf to run just the command needed to read the slabinfo file. For example, if telegraf is running as the user 'telegraf' and HOST_PROC is not used, add this to the sudoers file: telegraf ALL = (root) NOPASSWD: /bin/cat /proc/slabinfo

Metrics

Metrics include generic ones such as kmalloc_* as well as those of kernel subsystems and drivers used by the system such as xfs_inode. Each field with _size suffix indicates memory consumption in bytes.

• mem
  • fields:
    • kmalloc_8_size (integer)
    • kmalloc_16_size (integer)
    • kmalloc_32_size (integer)
    • kmalloc_64_size (integer)
    • kmalloc_96_size (integer)
    • kmalloc_128_size (integer)
    • kmalloc_256_size (integer)
    • kmalloc_512_size (integer)
    • xfs_ili_size (integer)
    • xfs_inode_size (integer)

Example Output

slab kmalloc_1024_size=239927296i,kmalloc_512_size=5582848i 1651049129000000000

Documentation

Index

• type SlabStats
  • func (ss *SlabStats) Gather(acc telegraf.Accumulator) error
  • func (ss *SlabStats) Init() error
  • func (*SlabStats) SampleConfig() string

Types

type SlabStats

type SlabStats struct {
	Log telegraf.Logger `toml:"-"`
	// contains filtered or unexported fields
}

func (*SlabStats) Gather

func (ss *SlabStats) Gather(acc telegraf.Accumulator) error

func (*SlabStats) Init

func (ss *SlabStats) Init() error

func (*SlabStats) SampleConfig

func (*SlabStats) SampleConfig() string