Documentation ¶
Overview ¶
Package statsd is a simple and efficient StatsD client.
Options ¶
Use options to configure the Client: target host/port, sampling rate, tags, etc.
Whenever you want to use different options (e.g. other tags, different sampling rate), you should use the Clone() method of the Client.
Because when cloning a Client, the same connection is reused so this is way cheaper and more efficient than creating another Client using New().
Internals ¶
Client's methods buffer metrics. The buffer is flushed when either:
- the background goroutine flushes the buffer (every 100ms by default)
- the buffer is full (1440 bytes by default so that IP packets are not fragmented)
The background goroutine can be disabled using the FlushPeriod(0) option.
Buffering can be disabled using the MaxPacketSize(0) option.
StatsD homepage: https://github.com/etsy/statsd
Example ¶
package main import ( "log" "runtime" "github.com/joeycumines/statsd" ) func ping(url string) {} func main() { c, err := statsd.New() // Connect to the UDP port 8125 by default. if err != nil { // If nothing is listening on the target port, an error is returned and // the returned client does nothing but is still usable. So we can // just log the error and go on. log.Print(err) } defer c.Close() // Increment a counter. c.Increment("foo.counter") // Gauge something. c.Gauge("num_goroutine", runtime.NumGoroutine()) // Time something. t := c.NewTiming() ping("http://example.com/") t.Send("homepage.response_time") // It can also be used as a one-liner to easily time a function. pingHomepage := func() { defer c.NewTiming().Send("homepage.response_time") ping("http://example.com/") } pingHomepage() // Cloning a Client allows using different parameters while still using the // same connection. // This is way cheaper and more efficient than using New(). stat := c.Clone(statsd.Prefix("http"), statsd.SampleRate(0.2)) stat.Increment("view") // Increments http.view }
Output:
Index ¶
- type Client
- func (c *Client) Clone(opts ...Option) *Client
- func (c *Client) Close()
- func (c *Client) Count(bucket string, n interface{})
- func (c *Client) Flush()
- func (c *Client) Gauge(bucket string, value interface{})
- func (c *Client) GaugeRelative(bucket string, value interface{})
- func (c *Client) Histogram(bucket string, value interface{})
- func (c *Client) Increment(bucket string)
- func (c *Client) NewTiming() Timing
- func (c *Client) Timing(bucket string, value interface{})
- func (c *Client) Unique(bucket string, value string)
- type Option
- func Address(addr string) Option
- func ErrorHandler(h func(error)) Option
- func FlushPeriod(p time.Duration) Option
- func InlineFlush(enabled bool) Option
- func MaxPacketSize(n int) Option
- func Mute(b bool) Option
- func Network(network string) Option
- func Prefix(p string) Option
- func SampleRate(rate float32) Option
- func Tags(tags ...string) Option
- func TagsFormat(tf TagFormat) Option
- func TrimTrailingNewline(enabled bool) Option
- func UDPCheck(enabled bool) Option
- func WriteCloser(writer io.WriteCloser) Option
- type SafeConn
- type TagFormat
- type Timing
- type UDPConn
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Client ¶
type Client struct {
// contains filtered or unexported fields
}
A Client represents a StatsD client.
func New ¶
New returns a new Client, which will always be non-nil, but will be muted (permanently inert / stubbed) if returned with an error, or if the Mute option was set.
func (*Client) Clone ¶
Clone returns a clone of the Client. The cloned Client inherits its configuration from its parent.
All cloned Clients share the same connection, so cloning a Client is a cheap operation.
Example ¶
package main import ( "log" "github.com/joeycumines/statsd" ) func main() { c, err := statsd.New(statsd.Prefix("my_app")) if err != nil { log.Print(err) } httpStats := c.Clone(statsd.Prefix("http")) httpStats.Increment("foo.bar") // Increments: my_app.http.foo.bar }
Output:
func (*Client) Close ¶
func (c *Client) Close()
Close flushes the Client's buffer and releases the associated ressources. The Client and all the cloned Clients must not be used afterward.
func (*Client) GaugeRelative ¶ added in v1.2.0
GaugeRelative records a relative value for the given bucket.
func (*Client) Increment ¶
Increment increments the given bucket. It is equivalent to Count(bucket, 1).
func (*Client) NewTiming ¶
NewTiming creates a new Timing.
Example ¶
package main import ( "github.com/joeycumines/statsd" ) var c *statsd.Client func ping(url string) {} func main() { // Send a timing metric each time the function is run. defer c.NewTiming().Send("homepage.response_time") ping("http://example.com/") }
Output:
type Option ¶
type Option func(*config)
An Option represents an option for a Client. It must be used as an argument to New() or Client.Clone().
func Address ¶
Address sets the address of the StatsD daemon.
By default, ":8125" is used. This option is ignored in Client.Clone().
Example ¶
package main import ( "github.com/joeycumines/statsd" ) var ( c *statsd.Client err error ) func main() { c, err = statsd.New(statsd.Address("192.168.0.5:8126")) }
Output:
func ErrorHandler ¶
ErrorHandler sets the function called when an error happens when sending metrics (e.g. the StatsD daemon is not listening anymore).
By default, these errors are ignored. This option is ignored in Client.Clone().
Example ¶
package main import ( "log" "github.com/joeycumines/statsd" ) var ( c *statsd.Client err error ) func main() { c, err = statsd.New(statsd.ErrorHandler(func(err error) { log.Print(err) })) }
Output:
func FlushPeriod ¶
FlushPeriod sets how often the Client's buffer is flushed. If p is 0, the goroutine that periodically flush the buffer is not launched and the buffer is only flushed when it is full.
By default, the flush period is 100 ms. This option is ignored in Client.Clone().
Example ¶
package main import ( "time" "github.com/joeycumines/statsd" ) var ( c *statsd.Client err error ) func main() { c, err = statsd.New(statsd.FlushPeriod(10 * time.Millisecond)) }
Output:
func InlineFlush ¶
InlineFlush enables or disables (default disabled) forced flushing, inline with recording each stat. This option takes precedence over FlushPeriod, which would be redundant if always flushing after each write. Note that this DOES NOT guarantee exactly one line per write.
This option is ignored in Client.Clone().
func MaxPacketSize ¶
MaxPacketSize sets the maximum packet size in bytes sent by the Client.
By default, it is 1440 to avoid IP fragmentation. This option is ignored in Client.Clone().
Example ¶
package main import ( "github.com/joeycumines/statsd" ) var ( c *statsd.Client err error ) func main() { c, err = statsd.New(statsd.MaxPacketSize(512)) }
Output:
func Mute ¶
Mute sets whether the Client is muted. All methods of a muted Client do nothing and return immediately.
This option can be used in Client.Clone() only if the parent Client is not muted. The clones of a muted Client are always muted.
Example ¶
package main import ( "log" "github.com/joeycumines/statsd" ) func main() { c, err := statsd.New(statsd.Mute(true)) if err != nil { log.Print(err) } c.Increment("foo.bar") // Does nothing. }
Output:
func Network ¶
Network sets the network (udp, tcp, etc) used by the client. See the net.Dial documentation (https://golang.org/pkg/net/#Dial) for the available network options.
By default, network is udp. This option is ignored in Client.Clone().
Example ¶
package main import ( "github.com/joeycumines/statsd" ) var ( c *statsd.Client err error ) func main() { // Send metrics using a TCP connection. c, err = statsd.New(statsd.Network("tcp")) }
Output:
func Prefix ¶
Prefix appends the prefix that will be used in every bucket name.
Note that when used in cloned, the prefix of the parent Client is not replaced but is prepended to the given prefix.
Example ¶
package main import ( "log" "github.com/joeycumines/statsd" ) func main() { c, err := statsd.New(statsd.Prefix("my_app")) if err != nil { log.Print(err) } c.Increment("foo.bar") // Increments: my_app.foo.bar }
Output:
func SampleRate ¶
SampleRate sets the sample rate of the Client. It allows sending the metrics less often which can be useful for performance intensive code paths.
Example ¶
package main import ( "github.com/joeycumines/statsd" ) var ( c *statsd.Client err error ) func main() { c, err = statsd.New(statsd.SampleRate(0.2)) // Send metrics 20% of the time. }
Output:
func Tags ¶
Tags appends the given tags to the tags sent with every metrics. If a tag already exists, it is replaced.
The tags must be set as key-value pairs. If the number of tags is not even, Tags panics.
If the format of tags have not been set using the TagsFormat option, the tags will be ignored.
Example ¶
package main import ( "github.com/joeycumines/statsd" ) var ( c *statsd.Client err error ) func main() { c, err = statsd.New( statsd.TagsFormat(statsd.InfluxDB), statsd.Tags("region", "us", "app", "my_app"), ) }
Output:
func TagsFormat ¶
TagsFormat sets the format of tags.
Example ¶
package main import ( "github.com/joeycumines/statsd" ) var ( c *statsd.Client err error ) func main() { c, err = statsd.New(statsd.TagsFormat(statsd.InfluxDB)) }
Output:
func TrimTrailingNewline ¶ added in v1.3.0
TrimTrailingNewline may be used to strip the trailing newline from writes, and should be used when providing a UDP writer (i.e. net.Conn), to WriteCloser. This behavior will always be enabled for UDP connections that use the Address option.
This option is ignored in Client.Clone().
func UDPCheck ¶ added in v1.1.0
UDPCheck enables or disables (default enabled) checking UDP connections, as part of New. This behavior is useful, as it makes it easier to quickly identify misconfigured services. Disabling this option removes the need to explicitly manage the connection state, at the cost of error visibility. Using an error handler may mitigate some of this cost. Explicitly setting this option to true will also enable this behavior for connections provided using the WriteCloser option (as part of New).
This option is ignored in Client.Clone().
func WriteCloser ¶
func WriteCloser(writer io.WriteCloser) Option
WriteCloser sets the connection writer used by the client. If this option is present it will take precedence over the Network and Address options. If the client is muted then the writer will be closed before returning. The writer will be closed on Client.Close. Multiples of this option will cause the last writer to be used (if any), and previously provided writers to be closed.
This option is ignored in Client.Clone().
type SafeConn ¶
type SafeConn struct {
// contains filtered or unexported fields
}
SafeConn is an implementation of the io.WriteCloser that wraps a net.Conn type its purpose is to perform a guard as a part of each Write call to first check if the connection is still up by performing a small read. The use case of this is to protect against the case where a TCP connection comes disconnected and the Write continues to retry for up to 15 minutes before determining that the connection has been broken off. See also the WriteCloser option.
func NewSafeConn ¶
type TagFormat ¶
type TagFormat uint8
TagFormat represents the format of tags sent by a Client.
const ( // InfluxDB tag format. // See https://influxdb.com/blog/2015/11/03/getting_started_with_influx_statsd.html InfluxDB TagFormat = iota + 1 // Datadog tag format. // See http://docs.datadoghq.com/guides/metrics/#tags Datadog )
type Timing ¶
type Timing struct {
// contains filtered or unexported fields
}
Timing is a helper object that eases sending timing values.
type UDPConn ¶ added in v1.3.0
type UDPConn struct {
// contains filtered or unexported fields
}
UDPConn is an implementation of an io.WriteCLoser, encapsulating a net.PacketConn, that supports DNS changes during operation. See also the WriteCloser, TrimTrailingNewline, and UDPCheck options.