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https://github.com/ribbybibby/ssl_exporter.git
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Rob BestandGitHub
801179eae7
There are a number of reasons for this change: - Modules allow a single instance of the exporter to be configured with numerous different tls configs. Previously you had to run a different exporter for each combination. - Adding new and more complicated options to the exporter should be easier with modules than if I was to go down the route of accepting configuration directly through url params - I prefer defining a specific prober (https,tcp) over using the URL to guess what the user wants
Backoff
A simple exponential backoff counter in Go (Golang)
Install
$ go get -v github.com/jpillora/backoff
Usage
Backoff is a time.Duration counter. It starts at Min. After every call to Duration() it is multiplied by Factor. It is capped at Max. It returns to Min on every call to Reset(). Jitter adds randomness (see below). Used in conjunction with the time package.
Simple example
b := &backoff.Backoff{
//These are the defaults
Min: 100 * time.Millisecond,
Max: 10 * time.Second,
Factor: 2,
Jitter: false,
}
fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())
fmt.Printf("Reset!\n")
b.Reset()
fmt.Printf("%s\n", b.Duration())
100ms
200ms
400ms
Reset!
100ms
Example using net package
b := &backoff.Backoff{
Max: 5 * time.Minute,
}
for {
conn, err := net.Dial("tcp", "example.com:5309")
if err != nil {
d := b.Duration()
fmt.Printf("%s, reconnecting in %s", err, d)
time.Sleep(d)
continue
}
//connected
b.Reset()
conn.Write([]byte("hello world!"))
// ... Read ... Write ... etc
conn.Close()
//disconnected
}
Example using Jitter
Enabling Jitter adds some randomization to the backoff durations. See Amazon's writeup of performance gains using jitter. Seeding is not necessary but doing so gives repeatable results.
import "math/rand"
b := &backoff.Backoff{
Jitter: true,
}
rand.Seed(42)
fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())
fmt.Printf("Reset!\n")
b.Reset()
fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())
100ms
106.600049ms
281.228155ms
Reset!
100ms
104.381845ms
214.957989ms
Documentation
https://godoc.org/github.com/jpillora/backoff
Credits
Forked from some JavaScript written by @tj