Andrei Skopenko scopenco

An Ansible summary

Jon Warbrick, July 2014, V3.2 (for Ansible 1.7)

Configuration file

First one found from of

Elastic Beanstalk Java JVM Settings

Determining the right memory settings (MX & MS) for the JVM is not trivial. If you set memory too low then your machine will trash as it runs out and eventually crash. If you set it too high then other critical processes such as Apache or the OS itself may become memory starved and also cause crashes.

In general, I think it best to set the initial memory setting (MS) to be small, around 200M. The real variable we need to calculate is the limit we will place on JVM memory (MS).

In order to make this determination, we need to calculate a few things such as the memory that Apache and the Linux OS need to operate efficiently.

Apache Memory Needs

Documentation-Driven Development

The philosophy behind Documentation-Driven Development is a simple: from the perspective of a user, if a feature is not documented, then it doesn't exist, and if a feature is documented incorrectly, then it's broken.

Document the feature first. Figure out how you're going to describe the feature to users; if it's not documented, it doesn't exist. Documentation is the best way to define a feature in a user's eyes.
Whenever possible, documentation should be reviewed by users (community or Spark Elite) before any development begins.
Once documentation has been written, development should commence, and test-driven development is preferred.
Unit tests should be written that test the features as described by the documentation. If the functionality ever comes out of alignment with the documentation, tests should fail.
When a feature is being modified, it should be modified documentation-first.
When documentation is modified, so should be the tests.

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

	This is a resize of the actual EBS volume as opposed to adding additional disks using LVM
	1. Follow the steps here: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/storage_expand_partition.html
	2. Use the instructions for gdisk further down the page to set the new partition table, not gparted or fdisk.
	3. Reboot the instance once the partition table is written.
	4. On the instance, execute:

	sudo pvresize /dev/xvda2 (or whatever the device name is)

	sudo pvdisplay

	Ohai.plugin(:Vboxipaddress) do
	provides "ipaddress"
	depends "ipaddress", "network/interfaces", "virtualization/system", "etc/passwd"
	collect_data(:default) do
	if virtualization["system"] == "vbox"
	if etc["passwd"].any? { \|k,v\| k == "vagrant"}
	if network["interfaces"]["eth1"]
	network["interfaces"]["eth1"]["addresses"].each do \|ip, params\|
	if params['family'] == ('inet')
	ipaddress ip