CM
Repository Manager 
Use
A CM repository is used as the main repository for storing documents and folders that are managed by CM.
Prerequisites
● You need to have installed a database for storing content and/or metadata.
For an overview of supported databases, see the SAP Service Marketplace at service.sap.com/platforms ® Product Availability Matrix.
● You must have defined the memory caches to be used by the repository managers (See below for more information.
Features
The CM repository manager supports all CM functions.
Persistence Modes
CM repository managers can be set up in various modes.
● All data (documents, folders, and metadata) is stored in the database (DB)
If there is a large number of write requests in your CM usage scenario, set up the CM repository in database mode. Since all documents are stored in the database, this avoids unintentional external manipulation of the data.
● Metadata and folders are stored in the database, but documents are stored in the file system (DBFS)
This mode is quicker than the database mode, and allows you easier control over the size of the database (since documents are stored in the file system).
Do not make any changes or manipulate files using the file system in DBFS mode.
● Metadata is stored in the database, but folders and documents are stored in the file system (FSDB)
In this mode, the file system is predominant. If files are removed from or added to the file system, the database is updated automatically. The automatic update can be switched off in the configuration of the repository manager using the parameter Disable Automatic FSDB Synchronization.
Note that metadata (for example, locks or custom properties) can be lost if
you edit or manipulate documents or folders directly in the file system. Only
administrators should work in the file system, and they should only carry out
mass operations such as copy and delete.
If the parameter Disable Automatic FSDB
Synchronization is active, you can use the synchronization report (see Reports) to avoid
metadata loss.
If you mainly have read requests, choose a mode in which content is stored in the file system. If this is the case, make sure that access to the relevant part of the file system is denied or restricted to other applications.
Resource Properties That Are Supported By the CM Repository Manager
The CM repository manager is the only repository manager that supports the entire spectrum of standard resource properties, including Description, Read-only, and Hidden. The default value of the Description property is blank, and the default value for Read-only and Hidden is ‘false’. The file system repository manager does not support these three properties.
Namespace Restrictions for Resource Names
·
Maximum
length of resource names:
FSDB: Restrictions of the file system are valid (Windows: 255 characters)
DBFS and DB: 448 characters
·
Maximum
length of path (URI without prefix):
FSDB: Restrictions of the file system are valid (Windows: 255 characters)
DBFS and DB: No restriction
·
Permitted
characters in resource names:
FSDB: Restrictions of the file system are valid (Unicode or Windows)
DBFS and DB: All Unicode characters, but restrictions may exist for some
components of the repository framework.
Do not put a full stop/period at the end of the resource name.
Database Restrictions
There are the following restrictions for the databases used:
●
Maximum
number of resources (folders, documents) in a repository instance:
FSDB: No restriction (possibly limited by file system restrictions)
DBFS and DB: 2,147,483,648
●
Maximum size
of an individual resource:
FSDB: No restriction (possibly limited by file system restrictions
DBFS: 8 exabytes (MS SQL Server 2000), 2 GB (Oracle)
DB: 2 GB
Maximum length of large property values (string type): 2,147,583,647 bytes (2 GB).
Persistent Caching in the File System
You are able to activate persistent caching for CM repositories that are operated in persistence mode DB or DBFS. An automatically generated cache saves the content of a document locally in the file system of the portal server, using the document ID. You can use this cache to help reduce database traffic, database accesses, and the network load.
The parameter File System Content Cache Directory is available when configuring a CM repository manager. You are able to restrict the size of the cache using the Max. Size of File System Cache and Maximum Number of Cache Files parameters. The criterion that is reached first restricts the size of the cache.
If you have configured persistent caching for a CM repository manager, each time that a document is launched, the system first looks in the cache to find out whether an entry is already available for the document. If you have configured persistent caching for a CM repository manager, each time a document is called up the system checks whether there is already an entry for the document in the cache. If the entry is not available in the cache, the corresponding content is fetched from the database, written to a temporary file, and compressed as GZIP.
If the document for a request is found in the cache, the relevant entry is unpacked and sent to the client. The cache entry is then given a new time stamp so that it is recorded correctly in the cache statistics.
Documents that have been changed are given a new ID and replaced by a new entry in the cache.
The ACLs of the original documents are adopted for the entries in the cache.
When you start Knowledge Management or reactivate a CM repository, the content of the cache is read in full, sorted internally, and staged. This process can take a certain amount of time depending on the number of entries.
The persistent cache of a CM repository, which is created automatically, is located in the cache monitor with the name <repository prefix>_fsContentCache. If you empty the cache, all entries are deleted in the file system. In a cluster environment, the cache monitor displays the ‘local’ load of the cache on the specific portal server. If you empty the cache, only those entries are deleted that are in the file system of this portal server.
Parameters of a CM Repository Manager
Parameter |
Required |
Description |
Name |
Yes |
Name of the repository manager. |
Description |
No |
Description of the repository manager. |
Prefix |
Yes |
The URI prefix for which the manager is registered. This specification is entered in the list in the root directory. The URIs of all resources managed by this repository manager have this prefix in common. This prefix is used to identify the repository manager that is responsible for a resource with a given URI. Note that you must enter the prefix with a forward slash, for example, /documents. |
Repository ID in Database |
No |
Identifier of the repository in the database. This is required because a database is generally used for storing the data of multiple repositories. The value must be an alphanumeric string that is unique amongst the IDs of all repositories that use the database. If the ID is not specified, the name of the repository is used as the ID. If you use an ID, the prefix can be changed without having to coordinate it with the database. Do not use special characters in the ID. |
Root Directory
|
No |
This parameter is only needed if the Persistence Mode parameter is set to FSDB or DBFS. It denotes the path to the root directory in the file system that the repository manager is assigned to. This can be a directory on the local server (for example, /usr/myshare/somedir) or on a released remote server. In order for you to access a file system of another UNIX host, the directory in question must be mounted on the portal server. The repository manager is responsible for this directory and all its subdirectories. Multiple repository managers are not allowed to share a subpath in their Root Directory parameter.
For security reasons, restrict authorizations for this path specification in the file system. |
Root Directory for Versions |
No |
The path to the root directory in the file system that is used to store versions. This parameter is only needed if the Persistence Mode parameter is set to FSDB. This cannot be the path specified in Root Directory or any of its subdirectories. If permissions have been assigned for the current version of a document, these are passed on to previous versions of the document. |
Windows Landscape System |
No |
Not required for CM repository managers on UNIX. |
Active |
No |
You can (de)activate the repository manager using the Active parameter. |
Auto Versioning |
No |
If this parameter is activated, users can change versioned documents without these having to be checked out beforehand and then checked in again. When documents of this type are saved, the system automatically creates a new version. If the parameter is deactivated, you must always check out versioned documents before you can make changes. After making the changes, you must check in the changed document again. |
Hide in Root Folder |
No |
Specifies whether the repository is listed in the root directory. If you activate this parameter, the repository is not listed in the root directory. |
Internal Links Default To Dynamic |
No |
If this is activated, newly created internal links always reference the item in question, even if the item is moved within the repository where it is located. If the object is deleted, the corresponding link is also deleted. |
Preserve Version Histories |
No |
Specifies whether versions are deleted or retained when the document they belong to is deleted. Activated: Versions are retained. Deactivated: Versions are deleted. The versions are located in the directory /.~system~ of the repository in question. This directory can only be called up using the admin explorer. If you activate this parameter, you should restrict the permissions for the directory /.~system~ of the repositories in question. Only allow system administrators to access this directory. You cannot use this parameter if the CM repository is run in persistence mode FSDB and the W2K security manager is implemented. |
Send Events |
No |
Specifies whether the repository sends events when operations such as delete and update content are performed. The repository sends events if this parameter is activated. This is necessary in order to use services such as the subscription service. |
Persistence Mode |
Yes |
Selection of persistence mode for CM repository manager. Defines where the namespace, content, and metadata are stored. If the database mode (DB) is specified, do not specify the Root Directory and Root Directory for Versions parameters, since they apply only to repositories that use the file system. Refer to the table below. |
Property Search Manager |
No |
Selection of the manager for the property search. Choose the CM Property Search Manager. |
Compress content greater than |
No |
Content greater than the specified value is stored in compressed form. |
Repository Services |
No |
Specifies the repository services that you want to use with the repository. |
ACL Manager Cache |
No |
Specifies a memory cache for resource ACLs: ca_rsrc_acl This parameter is required if an ACL security manager is specified in the Security Manager parameter. The cache is already created in the standard delivery (see Caches). |
Memory Cache |
No |
Specifies a memory cache to be used for the CM repository manager. The cache stores the names of resources, and properties and locks. No content is stored in the cache. |
Memory Cache for small Content (<32KB) |
No |
Specifies a memory cache to be used for content smaller than 32 KB. |
Security Manager |
No |
Selection of the security manager that controls access to repository content. If you want CM to perform an authorization check when resources are accessed, you need to specify a security manager. Generally, the AclSecurityManager is to be used for CM repositories. Only the CM repository /collaboration is to use the CollaborationSecurityManager. If you are running a CM repository in persistence mode FSDB under WINDOWS®, you can use the W2K security manager. |
File System Content Cache Directory |
No |
Specifies a folder in the local file system of the portal server in which the cache entries are stored persistently. Example: /tmp/cmcontentcache For more information, see the Persistent Caching in the File System section above. In a cluster environment, this folder has to be available to each computer in the cluster. You are not recommended to use the same folder for different CM repositories. You should also not specify a folder belonging to a remote server – this can lead to loss of performance.
For security reasons, restrict authorizations for this folder in the file system. |
Max. Size of File System Cache |
No |
Maximum size, in megabytes, that the persistent cache in the file system can hold. The size restriction refers to the compressed cache entries. -1 signifies no restriction. However, SAP does not recommend using this. |
Maximum Number of Cache Files |
No |
Maximum number of entries that the persistent cache in the file system can contain. -1 signifies no restriction. However, SAP does not recommend using this. After the last cache access, the entries are sorted. Old entries that are seldom called are removed from the cache and replaced with new entries. |
Disable Automatic FSDB Synchronization |
No |
Controls the synchronization of CM repositories that are operated in the persistent mode FSDB. If it is activated, automatic file system synchronization is not performed for the repository in question. Changes that are made directly in the file system (changes to properties, pasting, renaming/moving, deletion of folders or documents) are not automatically made in the database as well. These changes are not visible in the portal – accessing objects that no longer exist can lead to errors. In order to make these changes visible in the portal, you can use a report to start the file system synchronization manually as required (see CM Repository FSDB Synchronization) |
Read-only Content Expiry Delay |
No |
Specifies how long clients are to store the content of write-protected resources. During this time, write-protected resources are not reloaded from the client to the server. This specification is in seconds. You can only use this function if the persistence mode is set as either DB or DBFS. The cache options and the settings for the temporary internet files of the browser used need to be set to automatic. |
You enter particular parameters depending on the persistence mode chosen:
Persistence Modes and Root Parameters
Persistence Mode |
Required Parameters |
Unnecessary Parameters |
DB |
|
Root Directory |
DBFS |
Root Directory |
Root Directory for Versions |
FSDB |
Root
Directory Root Directory for Versions and Root Directory are not allowed to share subfolders or be identical. |
|
Activities
Several CM repositories are preconfigured in the KM standard configuration (see Internal Repositories). They are used as data and system repositories.
To create and configure a new CM repository manager for your own data, or to change the configuration of an existing one, choose Content Management ® Repository Managers ® CM Repository.
Configuration of the Necessary Memory Caches
You can specify three caches in the CM repository definition:
● ACL Manager Cache (ca_rsrc_acl)
● Memory Cache (ca_cm)
● Memory Cache for small Content (ca_cm_content)
The caches have already been preconfigured. You can adapt the configuration to your own requirements later on.
Activate the Singleton parameter when configuring a cache if your data is stored in CM repositories on one database. If you are using a ‘distributed’ database, you are not allowed to activate the singleton function, because objects in a cache cannot be uniquely assigned in a scenario with a distributed database.
If you are using Singleton for CM repositories, you can assign the same cache to all CM repositories. If several CM repositories are using the same cache, this has the advantage of better control of the number of caches, as well as having a performance advantage for file operations between CM repositories.
For more information on the configuration of caches, see Components and Their Caches.
Example
CM Repository Manager Configuration
Name =
documents
Description =
Standard repository for content
Prefix =
/documents
Repository-ID in DB = documents
Send
Events =
true
Persistence Mode = DB
Property Search Manager = CMPropertySearchManager
Repository Services = properties, feedback,
comment, rating,
accessstatistic,
personalnote, discussion,
tbp,
statemngt, subscription, svc_acl
ACL Manager Cache = ca_rsrc_acl
Memory
Cache =
ca_cm
Memory Cache for small Content = ca_cm_content
Security Manager =
AclSecurityManager
File System Content Cache
Directory = /tmp/cmdocumentscontentcache
Max. Size of File System
Cache = 100
Maximum Number of Cache
Files = 10000
The example above shows parameter settings for the documents repository manager that is included in the KM standard configuration. The manager stores both content and metadata in the database. Persistent caching is set up.
See also:
CM Repository File System Check
Non-Configured CM Repositories
CM Repository FSDB Synchronization