[英]Redis keyspace event not-firing
我有兩個redis客戶端,在一個文件中我有一個簡單的腳本設置並刪除了Redis鍵:
var redis = require("redis");
var client = redis.createClient('6379','127.0.0.1');
client.config("SET","notify-keyspace-events", "KEA");
client.set("string key 1", "string val", redis.print);
client.set("string key 2", "string val", redis.print);
client.set("placeholder","placeholder value", redis.print);
client.del("string key 1", redis.print);
client.del("string key", redis.print);
在第二個文件中,我有一個Redis客戶端作為訂閱者:
var redis = require("redis");
var subscriber = redis.createClient('6379','127.0.0.1');
const REDIS_PUB_MESSAGE = 'redis_pub_message';
const EVENT_SET = '__keyevent@0__:set';
const EVENT_DEL = '__keyevent@0__:del';
const SPACE_SPECIFIC_KEY = '__keyspace@0__:placeholder set';
const EVENT_SPECIFIC_KEY = '__keyevent@0__:placeholder set';
const SPACE_SPECIFIC_KEY_set = '__keyspace@0__:set placeholder';
const EVENT_SPECIFIC_KEY_set = '__keyevent@0__:set placeholder';
subscriber.on('message', function(channel, key) {
switch (channel) {
case SPACE_SPECIFIC_KEY_set:
console.log('space specific key channel:',channel,'key:',key);
case EVENT_SPECIFIC_KEY_set:
console.log('event specific key channel:',channel,'key:',key);
case EVENT_SPECIFIC_KEY:
console.log('space specific key channel:',channel,'key:',key);
case SPACE_SPECIFIC_KEY:
console.log('event specific key channel:',channel,'key:',key);
}
});
關鍵的'占位符'正在設置中,所以有沒有什么好的理由我沒有在'message'處理程序中獲得任何輸出?
您忘記將訂閱者客戶端訂閱到特定頻道。 此外,如果要監視所有事件,則需要使用基於模式的訂閱。
您可能想要做這樣的事情(未經測試):
subscriber.on("pmessage", function (pattern, channel, message) {
console.log("("+ pattern +")" + " client received message on " + channel + ": " + message);
switch (channel) {
// blah blah blah
// ...
}
});
subscriber.psubscribe(''__key*__:*')
請參閱Redis文檔和node_redis示例中的更多信息。
更新:
這是一個例子來說明頻道訂閱和模式訂閱之間的區別。 為簡潔起見,省略了適當的錯誤處理。
var redis = require("redis");
var client = redis.createClient('6379','127.0.0.1');
var subscriber1 = redis.createClient('6379','127.0.0.1');
var subscriber2 = redis.createClient('6379','127.0.0.1');
// First subscriber listens only to events occurring for key mykey
function S1(next) {
subscriber1.on('message', function(channel, msg) {
console.log( "S1: received on "+channel+" event "+msg )
});
subscriber1.subscribe( "__keyspace@0__:mykey", function (err) {
next();
});
}
// Second subscriber listens to events occuring for ALL keys
function S2(next) {
subscriber2.on('pmessage', function(pattern,channel, msg) {
console.log( "S2: received on "+channel+" event "+msg )
});
subscriber2.psubscribe( "__keyspace@0__:*", function (err) {
next();
});
}
// Do something with keys mykey and anotherkey
function do_something() {
client.set("mykey","example", function( err ) {
client.set("mykey", "another example", function( err ) {
client.del("mykey", function( err ) {
client.set("anotherkey","example", function( err ) {
client.del("anotherkey");
});
});
});
});
}
// Here we go
S1( function () {
S2( function () {
do_something();
});
});
這個腳本的結果是:
S1: received on __keyspace@0__:mykey event set
S2: received on __keyspace@0__:mykey event set
S2: received on __keyspace@0__:mykey event set
S1: received on __keyspace@0__:mykey event set
S1: received on __keyspace@0__:mykey event del
S2: received on __keyspace@0__:mykey event del
S2: received on __keyspace@0__:anotherkey event set
S2: received on __keyspace@0__:anotherkey event del
您可以看到第一個訂閱者只收到mykey的事件,而第二個訂閱者收到所有鍵的事件。
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