Memcache aprox

Question

I m 寻找一个储存的现成价值的系统,并自动消除的现时值。

Something like a RoundRobin system but, as long I understand, RoundRobin is based in an specific amount of records and removing as much old ones as much new ones are coming.

在这一制度中,可是任何数额记录,而只是删除那些高于特定时间滞后的记录。

一种近似可是一种系统,每个记录都有预留时间:

console.append "key", { :value => "value1", :timeout => 10.minutes_in_the_future }
console.append "key", { :value => "value2", :timeout => 10.minutes_in_the_future }
console.append "key", { :value => "value3", :timeout => 10.minutes_in_the_future }

And somehow the system is in charge to remove any expired record.

该系统可以建立在任何高性能储存系统(Redis, Memcache, ......)之上。

我不想仅仅想详细解释如何实施某种启发或任何相关的条款或现有制度,这样我就不希望发明轮.。

Answer 1

Memcache aprox

在办公室里,我们正在研究这一规定:

Preconditions

The time window is 10 minutes.
We only need to know the amount of records and not the values.
We can live with not very accurate solution.

Implementation

Create a new key every minute like: mykey_<Time.now.strftime("%Y%m%d%H%M")>.
Give them a expire time of 10 minutes.
Every time we want to add a record we incr the key for our actual minute.
To calculate the time window value we get the values of the 10 keys for the last 10 minutes and sum them.

Cons

We can not store real values but only one accumulate.
When every 1 minute key is expired the total value fluctuates suddenly.

Memcache aprox

Preconditions

Implementation

Cons

友情链接