Azure表存储和缓存

Question

Is it worth caching data from Azure Table storage with the Azure Caching Preview? Or is the table storage fast enough in large scale applications?

Thanks

Answer 1

The short answer is it depends . In the application I am currently working on there is some information that we use caching for to handle both the latency of retrieving data from Table Storage and to accommodate the desired number of transactions per second.

We started out serving the information from Table Storage and moved to caching only when our performance requirements dictated it. I'd recommend a similar approach: make it work, then make it fast.

Answer 2

In addition to what Robert said, you should also consider following points:

Windows Azure Table Storage allows to store up to 100TB in size (in chunks). At first glance, that size of data may seem overwhelming. However, Table Storage can be partitioned. Each partition of Table Storage can be moved to a separate server by the Azure controller thereby reducing the load on any single server and improving performance.

If you have very high load on your application, you cache with frequent inserts will approach the maximum cache size very quickly and then cache items eviction process starts. In most cases frequent inserts into cache and frequent cache items eviction processes end up with performance degradation instead of improvement. Then you would need to increase cache maximum size, which in turn will affect your application cost (sometimes this might be a blocker).

Last but not least, you can access Windows Azure Table Storage data using the OData protocol and LINQ queries with WCF Data Service .NET Libraries; you do not have that ability with Azure Cache.

Please bear in mind that those points may or may not be valid in your case. All depends on your system architecture; expected load etc.

I hope my answer will help you in making good system architecture decisions.