As we install the RBS provider (whereas it is RBS Filestream or RBS Extender), the WFE will have a supplemental load to cache the BLOB Metadata (CPU, Memory, Network) and to upload to the CIFS directory (with Extender RBS provider).
Few questions emerge :
- Is there a way to evaluate and calculate the load ? Memory cache on WFE can be configurable ?
- What is the role of the media service, I believe that in SMSP 6.1 the BLOB access with media service is no more used ?
In TR-3887, the SMSP 6.1 on 7-mode BPG talks about sizing the Ofifce Web Apps cache, but we have no specific guidance on configuring SharePoint 2010 BLOB caching on the WFEs.
According to the MS TechNet article, "Plan for caching and performance (SharePoint Server 2010)", http://technet.microsoft.com/en-us/library/ee424404.aspx, the BLOB cache is not enabled by default. The guidance in the document talks about understanding the content and the use of the content before enabling caching. In really large enviroments, dedicated caching servers can be deployed.
Enabling BLOB caching on the WFEs can help with performance, but also can become out of sync with the content. There is also a performance hit when content is injected into the cache for the first time. My opinion is that in most cases, customers will not benefit from enabling this feature.Before enabling BLOB caching, I would work with the customer's SharePoint consultant to see if the customer would benefit from this configuration.
The role of the media service is to manage devices used by SMSP (Backup Index, Archiver Data and Archiver Index, Extender Data and Extender Index). Also, the media service plays a role in indexing content in a content database backup and manages retention for these devices.
Starting in SMSP 6.0, the data path for the store and retrieval of Extender BLOBs no longer goes through the media server. For Extender, a CIFS share can only be used because of this change in data path. For Archiver BLOBs, the data path still goes throught the Media server because the of the Archiver rule complexity.