Write redis commands to a set of redises efficiently
npm install redis-broadcast
var RedisBroadcast = require('redis-broadcast');
// Define the redis servers, and whether or not
// they should be written to via child processes
var myRedisServers = new RedisBroadcast({
primary: [6379, 'localhost'],
secondary: [6379, 'some.other.server'],
tertiary: [6379, 'and.another.server'],
quaternary: [6379, 'and.another']
}, {
useChildProcesses: false,
customMethods: {
setnxOnce: [
function setnxOnce(key, val, callback) {
this.setnx(key, val, function(err, result) {
if(err || !result) {
callback(err || new Error('key already defined'));
} else {
callback(null, result);
}
});
},
'set'
]
}
});
// Write to only one server
var writePrimary = myRedisServers.writeTo('primary');
writePrimary.set('foo', 'bar', callback);
// Callback gets an object with the key being 'primary' and the value being an array of [err, result]
// { primary: 'OK' }
// Write to all servers
var writeAll = myRedisServers.writeTo('all');
writeAll.set('true', false, callback);
// Callback gets object of [err, result] arrays, keys matching server names
// {
// primary: 'OK',
// secondary: 'OK',
// tertiary: 'OK',
// quaternary: 'OK'
// }
// Write to a pair of servers in parallel
var writePrimarySecondary = myRedisServers.writeTo(['primary', 'secondary']);
writePrimarySecondary.set('fubar', true, callback);
// Gets object of [err, result] arrays, keys matching server names
// {
// primary: 'OK',
// secondary: 'OK'
// }
// Write to three servers in series, stopping if any returns an error
var write123 = myRedisServers.writeTo('primary').thenTo('secondary').thenTo('tertiary');
write123.set('hello', 'world', callback);
// Gets array of objects of [err, result] arrays, keys matching server names, order of objects matching write order
// [
// { primary: 'OK' },
// { secondary: 'OK' },
// { tertiary: 'OK' }
// ]
// Write to primary, then all remaining servers in parallel if no error
var writePrimaryThenRemaining = myRedisServers.writeTo('primary').thenTo('remaining');
writePrimaryThenRemaining.set('distributedOnlyIfSuccessful', true, callback);
// Gets an array; first value is an object with the primary key and an [err, result] array value,
// second is an object of [err, result] arrays, keys matching server names
// [
// { primary: 'OK' },
// {
// secondary: 'OK',
// tertiary: 'OK',
// quaternary: 'OK'
// }
// ]
// Write to primary, then all remaining servers in parallel if key doesn't already exist.
// NOTE: Custom functions must be 'pure' (not closures) to work on the child process.
var writePrimaryThenRemainingIfNew = myRedisServers.writeTo('primary').thenTo('remaining');
writePrimaryThenRemainingIfNew.setnxOnce('newkey', true, callback);
// Gets an array, the first array element gets the results of setnx, the second gets the results of set, if called
// [
// { primary: 1 },
// {
// secondary: 'OK',
// tertiary: 'OK',
// quaternary: 'OK
// }
// ]Copyright (C) 2013 by Uber Technologies, Inc
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.