53 lines
2.3 KiB
Markdown
53 lines
2.3 KiB
Markdown
# Go memory watchdog
|
|
|
|
> 🐺 A library to curb OOMs by running Go GC according to a user-defined policy.
|
|
|
|
[](https://godoc.org/github.com/raulk/go-watchdog)
|
|
|
|
go-watchdog runs a singleton memory watchdog. It takes system and heap memory
|
|
readings periodically, and feeds them to a user-defined policy to determine
|
|
whether GC needs to run immediately.
|
|
|
|
This library ships with two policies out of the box:
|
|
|
|
* watermarks policy: runs GC at configured watermarks of system or heap memory
|
|
utilisation.
|
|
* adaptive policy: runs GC when the current usage surpasses a dynamically-set
|
|
threshold.
|
|
|
|
You can easily build a custom policy tailored to the allocation patterns of your
|
|
program.
|
|
|
|
It is recommended that you set both (a) a memory limit and (b) a scope of
|
|
application of that limit (system or heap) when you start the watchdog.
|
|
Otherwise, go-watchdog will use the system scope, and will default to the
|
|
total system memory as the limit. [elastic/go-sigar](https://github.com/elastic/gosigar)
|
|
is used to make the discovery.
|
|
|
|
## Why is this even needed?
|
|
|
|
The garbage collector that ships with the go runtime is pretty good in some
|
|
regards (low-latency, negligible no stop-the-world), but it's insatisfactory in
|
|
a number of situations that yield ill-fated outcomes:
|
|
|
|
1. it is incapable of dealing with bursty/spiky allocations efficiently;
|
|
depending on the workload, the program may OOM as a consequence of not
|
|
scheduling GC in a timely manner.
|
|
2. part of the above is due to the fact that go doesn't concern itself with any
|
|
limits. To date, it is not possible to set a maximum heap size.
|
|
2. its default policy of scheduling GC when the heap doubles, coupled with its
|
|
ignorance of system or process limits, can easily cause it to OOM.
|
|
|
|
For more information, check out these GitHub issues:
|
|
|
|
* https://github.com/golang/go/issues/42805
|
|
* https://github.com/golang/go/issues/42430
|
|
* https://github.com/golang/go/issues/14735
|
|
* https://github.com/golang/go/issues/16843
|
|
* https://github.com/golang/go/issues/10064
|
|
* https://github.com/golang/go/issues/9849
|
|
|
|
## License
|
|
|
|
Dual-licensed: [MIT](./LICENSE-MIT), [Apache Software License v2](./LICENSE-APACHE), by way of the
|
|
[Permissive License Stack](https://protocol.ai/blog/announcing-the-permissive-license-stack/). |