5 Commits (e89c30ce6badcfa15cf435ebf86bc98ca71f4a42)

Author	SHA1	Message	Date
Danny Kopping	6bf5b5d8c1	Use a line-buffered logger to deamplify write syscalls (#6954) ... We initialise a global logger in `pkg/util/log/log.go` and use it extensively throughout the Loki codebase. Every time we write a log message, a `write` syscall is invoked. Syscalls are problematic because they transition the process from userspace to kernelspace, which means: - a context-switch is incurred, which is inherently expensive ([1-2 microseconds](https://eli.thegreenplace.net/2018/measuring-context-switching-and-memory-overheads-for-linux-threads/)) - the goroutine executing the code is **blocked** - the underlying OS thread (_M_ in the go scheduler model) is **also blocked** - the goroutine has to be rescheduled once the syscall exits - the go scheduler may need to spawn additional OS threads if all are blocked in syscalls - which can also be expensive This change introduces the use of a line-buffered logger. It has a buffer of [256](https://gist.github.com/dannykopping/0704db32c0b08751d1d2494efaa734c2) entries, and once that buffer is filled it will flush to disk. However, a situation will arise in which that buffer remains somewhat empty for a period of time, so there is a periodic flush mechanism, configured to flush every 100ms. There is also a preallocated bytes slice of 10MB which is reused, to avoid excessive slice resizing & garbage collection. This does mean that we could lose up to 256 log messages in case of an ungraceful termination of the process, but this would need to be precisely timed within the 100ms flushes - in other words, the likelihood is low, and generally we shouldn't `kill -9` any Loki process.	4 years ago
Jesus Vazquez	db9dbe8e1d	Bump prometheus dependency (#6403) ... * Bump prometheus dependency We had to add a replace of prometheus in go mod because thanos is importing an older version and then replacing it. * Undo textparser.New variable mismatch * modtimevfs path update * Fix labels withlabels and withoutlabels usages WithoutLabels and WithLabels methods have dissappeared. Now labels.NewBuilder has to be used. * Fix RuleManager interface for Update() Update now accepts a new param called ruleGroupPostProcessFunc which is an optional function to be executed after rule group processing. In this case I've set it to nil in the usages i've found. * NewQueryRange now accepts QueryOpts The NewQueryRange function now accepts QueryOptions so I had to update all the calls. I've set the opts to nil since we're not using them. * gofmt	4 years ago
Callum Styan	6da518c728	Update to go 1.17; go mod vendor required (#4487) ... Signed-off-by: Callum Styan <callumstyan@gmail.com>	5 years ago
Danny Kopping	cff8324f24	Replacing go-kit/kit/log with go-kit/log (#4484) ... * Replacing go-kit/kit/log with go-kit/log Signed-off-by: Danny Kopping <danny.kopping@grafana.com> * Appeasing the f&^$ing linter Signed-off-by: Danny Kopping <danny.kopping@grafana.com> * Adding depguard Cleaning go mod Signed-off-by: Danny Kopping <danny.kopping@grafana.com> * Updating weaveworks after https://github.com/weaveworks/common/pull/226 was merged Signed-off-by: Danny Kopping <danny.kopping@grafana.com> * Appeasing the mod checker Signed-off-by: Danny Kopping <danny.kopping@grafana.com>	5 years ago
Arve Knudsen	3e385464c6	Chore: Upgrade Prometheus and Cortex (#4017) ... * Chore: Upgrade Prometheus Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com> * Upgrade Cortex Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com> * Upgrade Cortex Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com> * Fix build errors Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com> * Fix build errors Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com> * Fix build errors Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com> * Undo unnecessary changes Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>	5 years ago