Boundaries are absolute limits within SharePoint that were created by design and cannot be exceeded. Although these boundaries are few in number when compared with the sheer quantity of options and settings available, they shape the design of a SharePoint infrastructure.
This boundary structure is present in many of the logical, hierarchical components of a SharePoint farm. Although not present in each level of the component hierarchy, boundaries exist in each of the following levels:
- Web applications
- Content databases
- Site collections
- Lists and libraries
- Search
- Business Connectivity Services (BCS)
- Workflows
- PerformancePoint Services
- Word Automation Services
- Office Web Application Service
- Project Server
- SharePoint apps
- Distributed Cache Service
Only major boundaries will be explained in this section on a per-hierarchy basis. For more detail on the boundaries present in any given hierarchical level, see the TechNet article “Software Boundaries and Limits for SharePoint 2013” at http://technet.microsoft.com/enus/library/cc262787.aspx.
Web application boundaries
Boundary: The number of zones defined for a farm is hard-coded to 5. Zones include Default, Intranet, Extranet, Internet, and Custom.
Note that the names of these zones are just that—names. With the exception of the Default zone (certain administrative functionality works only with this zone), all other zones are technically interchangeable. You can extend a web application to any of the zones and add the new name to DNS; the zone should work.
Content database boundaries
Boundary: Time to first byte of any response from the Network Attached Storage (NAS) cannot exceed 20 milliseconds.
If you are using RBS on a NAS device, that device must be able to start responding with 20 ms to function with SharePoint.
Improving the network access to the NAS or replacing it altogether are the only remedies for this boundary.
Site collection limits
Boundary: The maximum number of device channels per publishing site collection is 10.
Device channels (new in SharePoint 2013) is a mechanism whereby an incoming request is mapped to a particular mobile device type. It enables a distinct master page to be applied to each device channel.
The remedy for this boundary is to support 10 or fewer distinct device channels, combining the support for a particular mobile device with that or another (finding a master page that works for both).
Major list and library limits
Boundary 1: Each list or library item can occupy only 8,000 bytes in total in the database. Two hundred fifty-six bytes are reserved for built-in columns, which leaves 7,744 bytes for end-user columns.
Column values promoted from within InfoPath (or defined within the list or library) consume space in SQL Server tables. The total size consumed has to do with the type of data being stored (String, Boolean, and so on), and if enough column values are used, a value can consume multiple rows in the table, which slows down performance.
Although it may take hundreds of columns to reach this boundary limit, it can happen nonetheless. The only choice of solutions is to change the type of data being captured (see Column Limits in the Boundaries and Limits document) or restrict the amount of columns in a
list.
Boundary 2: The maximum file size in any list or library is limited to 2 GB.
The default maximum file size in SharePoint is 250 MB. Although this value is generally adequate for most uses, it occasionally has to be altered to accommodate larger files. The maximum upper limit for this file size is a hard limit of 2 GB.
Major search limits
Boundary 1: There is a hard limit of five crawl databases per search service application.
If you find that the crawl database is becoming I/O bound on your SQL server, and you cannot move it, one option is to add one or more additional crawl databases on the same SQL Server but on different I/O devices.
After you reach a total of five crawl databases, you must consider replacing one of the I/O devices, preferably one with the least I/O capability.
Boundary 2: There is a maximum size limit for documents pulled down by the crawler (3 MB for Excel documents; 64 MB for all others).
Each document in a content source is crawled and must be processed by search in SharePoint. Crawl will process only the first 3 MB of Excel documents and the first 64 MB of all other document types.
Although there are dozens of boundaries in SharePoint, there are a few that every administrator should know by heart. Maximum file size, zones in a farm, and crawl document size limits are all good metrics to be familiar with.
