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Heimdall Data:自動 Cache RDBMS 資料增加效能

看到 AWS 的「Automating SQL Caching for Amazon ElastiCache and Amazon RDS」這篇裡面介紹了 Heimdall Data – SQL caching and performance optimization 這個產品。

從官網的介紹也可以看出來是另外疊一層 proxy,但自動幫你處理 cache invalidation 的問題:

But what makes Heimdall Data unique in industry is its auto-cache AND auto-invalidation capability. Our machine learning algorithms determine what queries to cache while invalidating to ensure maximum performance and data integrity.

看起來支援了四個蠻常見的 RDBMS:

Heimdall Data supports most all relational database (e.g. MySQL, Postgres, Amazon RDS, Oracle, SQL Server, MariaDB).

看起來是一個花錢直接買效能的方案... 不過 cache invalidation 的部分不知道要怎麼跨機器做,在 FAQ 沒看到 cluster 情況下會怎麼解決。

CloudFront 支援 Wildcard Invalidation

在「Amazon CloudFront Makes it Easier to Invalidate Multiple Objects」這邊看到的消息,Amazon CloudFront 總算是支援 Wildcard Invalidation 了。價錢與 Single Object Invalidation 相同,都是每次 USD$0.005。

依照 Invalidating Objects (Web Distributions Only) 這邊的說明,Wildcard 的部份只能用在結尾:

To invalidate objects, you can specify either the path for individual objects or a path that ends with the * wildcard, which might apply to one object or to many, as shown in the following examples:

  • /images/image1.jpg
  • /images/image*
  • /images/*

不過還是有些限制,包括了 Single Object Invalidation 的同時最多 3000 條的限制:

If you're invalidating objects individually, you can have invalidation requests for up to 3,000 objects per distribution in progress at one time. This can be one invalidation request for up to 3,000 objects, up to 3,000 requests for one object each, or any other combination that doesn't exceed 3,000 objects. For example, you can submit 30 invalidation requests that invalidate 100 objects each. As long as all 30 invalidation requests are still in progress, you can't submit any more invalidation requests. If you exceed the limit, CloudFront returns an error message.

以及 Wildcard Invalidation 的同時 15 條限制:

If you're using the * wildcard, you can have requests for up to 15 invalidation paths in progress at one time.

而且每次 invalidate 可能都要 10~15 分鐘:

It usually takes 10 to 15 minutes for CloudFront to complete your invalidation request, depending on the number of invalidation paths that you included in the request.

所以也不是付錢就可以解決所有事情... :o

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