Bryan Hunt binarytemple

Loading modules

Purging = removing the old version of the module (so that it will only have a new version).

erlang:check_old_code(mymodule).

Return if the module has an old version loaded.

code:load_file(mymodule).

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 :)

#Map Reduce Delete Instructions

Set allow_strfun true on all nodes:

echo "rpc:multicall([node() | nodes()], application,set_env,[riak_kv,allow_strfun,true])." | bin/riak attach

Insert 15000 keys:

for i in {1..15000}; do curl -XPUT http://127.0.0.1:9000/buckets/test/keys/test$i -H "content-type: text/plain" -d "Data #$i\n"; done

	<Plugin "processes">

	ProcessMatch "carbon-cache" "python.+carbon-cache"
	ProcessMatch "carbon-aggregator" "python.+carbon-aggregator"

	</Plugin>

	#! /bin/bash

	echo Creating Combined console.log
	for I in -riak-debug; do NODE=${I//-riak-debug/}; echo " Processing ${NODE}..."; for J in $I/logs/platform_log_dir/console.lo; do sed -n -e '/^2015/!{H;d;};/^2015/{x;s/\n/ /g;p;};${x;s/\n/ /g;p;}' $J \| awk '!/^$/{print $1"T"$2,"'${NODE}'",$0}' \| sed 's/\([^ ]\) \([^ ]\) \([^ ]\) \([^ ]\) \(.*\)/\1 \2 \5/' >> temp.log ; done; done; sort temp.log > combined_console.log;rm temp.log;

	echo Creating Combined error.log
	for I in -riak-debug; do NODE=${I//-riak-debug/}; echo " Processing ${NODE}..."; for J in $I/logs/platform_log_dir/error.lo; do sed -n -e '/^2015/!{H;d;};/^2015/{x;s/\n/ /g;p;};${x;s/\n/ /g;p;}' $J \| awk '!/^$/{print $1"T"$2,"'${NODE}'",$0}' \| sed 's/\([^ ]\) \([^ ]\) \([^ ]\) \([^ ]\) \(.*\)/\1 \2 \5/' >> temp.log ; done; done; sort temp.log > combined_error.log;rm temp.log;

	echo Checking for LevelDB Compaction Errors
	find . -name "LOG" -exec grep -l 'Compaction error' {} \;

	This gist captures what needs to be done to add a new field to Riak's Yokozuna
	search index.

	Sources:
	- https://github.com/basho/yokozuna/issues/130
	- http://riak-users.197444.n3.nabble.com/How-to-update-existed-schema-td4032143.html

	The code below is for illustration purposes only. Use at your own risk.

	1. Create/Update new schema file

	%% riak_dt_map: OR-Set schema based multi CRDT container
	M = riak_dt_map:new(),
	%% Braxton adds key and val fields
	{ok, M1B} = riak_dt_map:update({update, [
	{add, {key, riak_dt_lwwreg}},
	{add, {val, riak_dt_pncounter}}
	]}, braxton, M),
	%% Braxton sets key to 'a' and increments val by 1
	{ok, M2B} = riak_dt_map:update({update, [
	{update, {key, riak_dt_lwwreg}, {assign, a}},

	%% These are shell functions that can be used to output a keylist from a bitcask file in terms of Riak {Bucket,Key} tuples
	%% They should be run from `riak attach`. Paste in the contents and run ListAll("filename.txt"). Profit.

	ListCask = fun(Vnode,OutFile) ->

	Fold_data = fun(Handle) ->
	FoldFun = fun(Bytes, X, Y, {ok, Acc}) ->
	case Bytes of
	<<1:7, 0:1,Sz:16/integer,Bucket:Sz/bytes, Key/binary>> ->
	io:format(OutFile, "~s/~s~n", [binary_to_list(Bucket),binary_to_list(Key)]), {ok, Acc + 1};