Hrishikesh (Hrish) Barua talonx

In a perfect world, where things are done well, not just quickly, I would expect to find the following when joining the company:

Documentation

Accurate / up-to-date systems architecture diagram
Accurate / up-to-date network diagram
Out-of-hours support plan
Incident management plan

Orien is correct, it is the fork() system call triggered by ProcessBuilder or Runtime.exec or other means of the JVM executing an external process (e.g. another JVM running ant, a git command, etc.).

There have been some posts on the Jenkins mailing lists about this: Cannot run program "git" ... error=12, Cannot allocate memory

There is a nice description of the issue on the SCons dev list: fork()+exec() vs posix_spawn()

There is a long standing JVM bug report with solutions: Use posix_spawn, not fork, on S10 to avoid swap exhaustion. But I'm not sure if this actually made it into JDK7 as the comments suggest was the plan.

In summary, on Unix-like systems, when one process (e.g. the JVM) needs to launch another process (e.g. git) a system call is made to

	###################################################
	##
	## Alertmanager YAML configuration for routing.
	##
	## Will route alerts with a code_owner label to the slack-code-owners receiver
	## configured above, but will continue processing them to send to both a
	## central Slack channel (slack-monitoring) and PagerDuty receivers
	## (pd-warning and pd-critical)
	##

	node {
	echo 'Results included as an inline comment exactly how they are returned as of Jenkins 2.121, with $BUILD_NUMBER = 1'
	echo 'No quotes, pipeline command in single quotes'
	sh 'echo $BUILD_NUMBER' // 1
	echo 'Double quotes are silently dropped'
	sh 'echo "$BUILD_NUMBER"' // 1
	echo 'Even escaped with a single backslash they are dropped'
	sh 'echo \"$BUILD_NUMBER\"' // 1
	echo 'Using two backslashes, the quotes are preserved'
	sh 'echo \\"$BUILD_NUMBER\\"' // "1"

	---
	- name: Capture files in path and register
	shell: >
	ls -1 /path/to/files
	register: files

	- name: Remove files except specified
	file:
	path: "/path/to/files/{{ item }}"
	state: absent

	(Chapters marked with * are already written. This gets reorganized constantly
	and 10 or so written chapters that I'm on the fence about aren't listed.)

	Programmer Epistemology
	* Dispersed Cost vs. Reduced Cost
	* Verificationist Fallacy
	* Mistake Metastasis
	The Overton Window
	Epicycles All The Way Down
	The Hyperspace Gates Were Just There

	package main

	import (
	"fmt"
	)

	func decorator(f func(s string)) func(s string) {

	return func(s string) {
	fmt.Println("Started")

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	Host github.com
	User git
	Hostname github.com
	PreferredAuthentications publickey
	IdentityFile /home/user/.ssh/id_rsa