lenary

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?

bsparrow435

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

bsparrow435

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

zkessin

Why You should use Erlang for your startup's API

Zachary Kessin zkessin@gmail.com 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,

angrycub

riak-admin force-remove should not exist.

It's Friday evening, almost time to head out of the office for a nice long weekend. Your Riak cluster has been running along, everything fine. All of a sudden, the SSD in one of your Riak nodes decides to go up in a ball of flames. So you, being the good sysadmin that you are, immediately hop on the phone with your hardware vendor and order a new SSD. They tell you that you'll have it on Monday morning. Clearly you can't leave a broken node in your Riak environment, so you'll want to remove it from the cluster. You sit down at your terminal, hop on to a working Riak node and type

riak-admin force-remove riak@deadnode.mycompany.com

NOOOOOOOOOOOOOOOOOOOOOOOOO!!!!

bsparrow435

Step 1: From you logs I have decoded the bucket/key

binary_to_term(<<131,109,0,0,0,9,85,114,108,84,111,83,99,97,110>>).
<<"UrlToScan">>
binary_to_term(<<131,109,0,0,0,61,104,116,116,112,37,51,97,37,50,102,37,50,102,119,119,119,46,97,110,104,114,105,46,110,101,116,37,50,102,37,51,102,102,101,101,100,37,51,100,114,115,115,50,37,50,54,97,109,112,37,51,98,112,37,51,100,55,51,49,49,48>>).
<<"http%3a%2f%2fwww.anhri.net%2f%3ffeed%3drss2%26amp%3bp%3d73110">>

Step 2: Please run the below snippits from riak attach to identify the owning partitions of this bucket/key

argv0

simple_test() ->
    {ok, EC} = erasuerl:new(),
    {ok, Bin} = file:read_file("/usr/share/dict/words"),
    {MD, KBins, MBins} = erasuerl:encode(EC, Bin),
    [K1, K2, K3, K4, K5, K6, K7, K8, K9] = KBins,
    [M1, M2, M3, M4] = MBins,
    KBins2 = [undefined, undefined, undefined, K4, K5, K6, K7, K8, K9],
    MBins2 = [undefined, M2, M3, M4],
    Bin = iolist_to_binary(erasuerl:decode(EC, MD, KBins2, MBins2)).

bookshelfdave

/* comments */
// comments

Connections, misc

// default connection, this is used if a named connection 
// is not specified in a fetch, put, delete

ericmoritz

-module(erlmonad).

-compile(export_all).


half(X) when X rem 2 =/= 0 ->
    nothing;
half(X) ->
    X div 2.

andelf

#!/usr/bin/env escript
% -*- mode: erlang -*-

main([BeamFile]) ->
    {ok,{_,[{abstract_code,{_,AC}}]}} = beam_lib:chunks(BeamFile,[abstract_code]),
    io:fwrite("~s~n", [erl_prettypr:format(erl_syntax:form_list(AC))]).