swirl
High Performance Erlang Stream Processor
Requirements
- Erlang 16.0 +
Environment variables
| Name | Type | Default | Description |
|---|---|---|---|
| mappers_max | pos_integer() | 100 | maximum number of mappers |
| reducers_max | pos_integer() | 100 | maximum number of reducers |
Examples
Starting a flow
ok = application:start(swirl),
FlowMod = swirl_flow_example,
FlowOpts = [
{stream_names, [delivery]},
{stream_filter, "exchange_id = 3 AND bidder_id IS NOT NULL"}
],
MapperNodes = [node()],
ReducerNode = node(),
{ok, Flow} = swirl_flow:start(FlowMod, FlowOpts, MapperNodes, ReducerNode),
StreamName = delivery,
Event = #{exchange_id => 1, bidder_id => 10},
swirl_stream:emit(StreamName, Event),
ok = swirl_flow:stop(Flow)Implementing a flow
-module(swirl_flow_example).
-include_lib("swirl/include/swirl.hrl").
-behavior(swirl_flow).
-export([
map/3,
reduce/3,
output/4
]).
%% swirl_flow callbacks
map(StreamName, Event, _MapperOpts) ->
Type = ?L(type, Event),
ExchangeId = ?L(exchange_id, Event),
BidderId = ?L(bidder_id, Event),
Key = {Type, StreamName, ExchangeId, BidderId},
CounterIncrements = {1, 10},
{Key, CounterIncrements}.
reduce(_Flow, Row, _ReducerOpts) ->
Row.
output(_Flow, _Period, Rows, OutputOpts) ->
%% do something with the output
io:format("rows: ~p~n", [Rows]),Stream Filter
exchange_id = 3 AND bidder_id IS NOT NULL
flight_id in (10, 12, 23) OR tag_id = 20
buyer_id notnull AND seller_id > 103Swirl QL
variables:
atom()
values:
integer() | float() | binary()
boolean operators:
'and' | 'or'
comparison operators:
'<' | '<=' | '=' | '>=' | '>' | '<>'
inclusion operators:
in | notin
null operators:
null | notnull
TODO
- node discovery
- boolean expression indexing
Tests
make dialyzer
make elvis
make eunit
make xrefLicense
The MIT License (MIT)
Copyright (c) 2013-2016 Louis-Philippe Gauthier
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this software and associated documentation files (the "Software"), to deal in
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