John Daily macintux

Why You should use Erlang for your startup's API

Zachary Kessin [email protected] Director of API Product Structure Mostly Erlang Podcast

Building a statup in which an API plays a key part is an increasingly common pursuit. People have used many technologies to build those APIs,

Put

API

Starting: https://github.com/basho/riak_kv/blob/1.4.2/src/riak_kv_wm_object.erl#L619
We create a new riak_object and populate the various fields with the headers, metadata supplied by the client.
Big suprise, we eventually call riak_client:put: https://github.com/basho/riak_kv/blob/1.4.2/src/riak_client.erl#L143
If/when the client returns any errors these are handled in handle_common_errors and it is nice to return human readable errors to client :)

Riak_client

API

HTTP

Entry point for all object operations: https://github.com/basho/riak_kv/blob/1.4.2/src/riak_kv_wm_object.erl

delete_resource/2 takes RequestData(Request header, ex: vclock) and Context(Record containing: Bucket, Key, Client): https://github.com/basho/riak_kv/blob/1.4.2/src/riak_kv_wm_object.erl#L888

I've had one question about subpar performance in Riak 2.0's CRDTs. I thought I'd write this so that people can more easily diagnose these issues, without the CRDT team having to step in every time.

An Example: A Client was having problems with the performance fetching and updating sets. The issue manifested itself with poor fetch performance.

So, how do you go about debugging/diagnosing this?

Testing Notes

At this time only the protocol buffers client supports client certificates. HTTP is not supported.

Setup

Setting up a Root CA

It is necessary to set up a Root Certificate authority to be able to create and sign certificates.

Erlang Tracing: more than you wanted to know

Rough Outline

What can be traced?
How can trace events be specified?
"match specifications": twisty passages, all alike
WTF, can I just use DTrace and drink my coffee/beer/whisky in peace?
Trace delivery mechanisms: pick one of two

DDD, CQRS and Event Sourcing

In preparation for a new gig I'm reading up on the terms Domain-Driven Design, Command-Query Responsibility Segregation, and Event Sourcing. Here are a list of useful texts and talks that I've discovered so far. If anything is missing please leave a comment.

DDD

Eric Evans: What is a model? - "A model is not a UML diagram nor a certain layer of the software. [...]. It is a system of abstractions, it describes selected aspects of a domain, and can be used to solve problems related to that domain."
Eric Evans: What I've learned since the book - slightly longer talk on Eric's findings since he co-authored the book on DDD.
Eric Evans: Domain-Driven Design - As far as I can tell, the book on DDD. Haven't read it though.

See the more recent gist.

Hiring!

The Dell Cloud Manager engineering team is growing. We're looking for seven new software developers at many different experience levels.

In this gist, I want to give you an idea of:

	The regex patterns in this gist are intended only to match web URLs -- http,
	https, and naked domains like "example.com". For a pattern that attempts to
	match all URLs, regardless of protocol, see: https://gist.github.com/gruber/249502


	# Single-line version:

	(?i)\b((?:https?:(?:/{1,3}\|[a-z0-9%])\|[a-z0-9.\-]+[.](?:com\|net\|org\|edu\|gov\|mil\|aero\|asia\|biz\|cat\|coop\|info\|int\|jobs\|mobi\|museum\|name\|post\|pro\|tel\|travel\|xxx\|ac\|ad\|ae\|af\|ag\|ai\|al\|am\|an\|ao\|aq\|ar\|as\|at\|au\|aw\|ax\|az\|ba\|bb\|bd\|be\|bf\|bg\|bh\|bi\|bj\|bm\|bn\|bo\|br\|bs\|bt\|bv\|bw\|by\|bz\|ca\|cc\|cd\|cf\|cg\|ch\|ci\|ck\|cl\|cm\|cn\|co\|cr\|cs\|cu\|cv\|cx\|cy\|cz\|dd\|de\|dj\|dk\|dm\|do\|dz\|ec\|ee\|eg\|eh\|er\|es\|et\|eu\|fi\|fj\|fk\|fm\|fo\|fr\|ga\|gb\|gd\|ge\|gf\|gg\|gh\|gi\|gl\|gm\|gn\|gp\|gq\|gr\|gs\|gt\|gu\|gw\|gy\|hk\|hm\|hn\|hr\|ht\|hu\|id\|ie\|il\|im\|in\|io\|iq\|ir\|is\|it\|je\|jm\|jo\|jp\|ke\|kg\|kh\|ki\|km\|kn\|kp\|kr\|kw\|ky\|kz\|la\|lb\|lc\|li\|lk\|lr\|ls\|lt\|lu\|lv\|ly\|ma\|mc\|md\|me\|mg\|mh\|mk\|ml\|mm\|mn\|mo\|mp\|mq\|mr\|ms\|mt\|mu\|mv\|mw\|mx\|my\|mz\|na\|nc\|ne\|nf\|ng\|ni\|nl\|no\|np\|nr\|nu\|nz\|om\|pa\|pe\|pf\|pg\|ph\|pk\|pl\|pm\|pn\|pr\|ps\|pt\|pw\|py\|qa\|re\|ro\|rs\|ru\|rw\|sa\|sb\|sc\|sd\|se\|sg\|sh\|si\|s

	com.factual.polyglot.JSFunction.call(JSFunction.java:54)
	com.factual.scarecrow.rules.Function.call(Function.java:27)
	com.factual.scarecrow.rules.FunctionContainer.call(FunctionContainer.java:42)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	java.lang.reflect.Method.invoke(Method.java:606)
	org.jruby.javasupport.JavaMethod.invokeDirectWithExceptionHandling(JavaMethod.java:425)
	org.jruby.javasupport.JavaMethod.invokeDirect(JavaMethod.java:292)
	org.jruby.java.invokers.InstanceMethodInvoker.call(InstanceMethodInvoker.java:44)