Repository Objects Caching

To speed up access to objects and to provide their work, use repository objects caching.

On Foresight Analytics Platform BI server working, extraction and storage of data required for web application work is made in the BI server memory.

The system can be expanded by introducing additional (more powerful) servers with function of data extraction and caching from repository. BI server will request these BI servers and get the thread with required data without additional request to DBMS. To introduce additional BI servers, fill in the Service section in the settings.xml file or in system registry settings.

To use dictionary or time series database caching:

Select the repository object in the object navigator.
Enable caching using the Cacheable Object checkbox on the Cache tab in the object properties.

After executing the operations, caching of the selected repository object is used.

When dictionaries and time series databases are cached, the system creates temporary copies of the object containing element attribute values and links to the used objects in RAM.

Caching of dictionaries and time series database is intelligent and available for a number of users if they have similar access permissions and use the same parameter values. Different values of dictionary parameters and time series database parameters can have several instances of the same object cached simultaneously.

To use regular report caching:

Select the repository object in the object navigator.
Enable caching by selecting the Object Cache context menu item.

After executing the operations, caching of the selected repository object is used.

When regular report caching is used, the system creates instances of the object opened with certain parameter values in the repository database. When an object is opened with some parameters, the cache is checked for availability of a record corresponding to these parameters. If such a record is found, cached object version is extracted and opened. If no record is found for the specified parameters, the last object version is opened from the repository. All the objects, on which this object depends, are also opened.

Compiled versions of objects are cached for repository objects. Cache speeds up startup of forms and execute application code on application projects work.

When compiling units/forms/assemblies, a file cache, which stores a compiled object version, is created on the local drive. When working in Linux OS, cache is located on the BI server in the subfolder opt/foresight/fp10.x-biserver/var/cache/AsmCache<n>/Mod/<repository ID>/<build number>/. When working in Windows OS, cache is located by default in the user profile in the subfolder \AppData\Local\Foresight\Foresight Analytics Platform\AsmCache<n>\Mod\<repository ID>\<build number>\. If required, file cache storage path can be changed. To do this, in the registry key [HKEY_CURRENT_USER\Software\Foresight\Foresight Analytics Platform\10.0\10.4] create the CachefilePath string parameter and set up required path in it.

To speed up the startup of objects in production version, compiled object versions can also be stored in the repository database. The Cache Assemblies on Local Drive Only checkbox is used to control storing mode of compiled objects. The checkbox is located in the Set Up Repository Connection dialog box and is hidden by default. If the object is compiled by one user, its cached version is saved to a file and then to the repository database. When being compiled or started the object by another user, the system checks if there is a cached version in the repository database, then it is copied to the drive and the user works with the file cache.

Recommendations:

Select the Cache Assemblies on Local Drive Only checkbox on the workstations used for project development.
Select the Cache Assemblies on Local Drive Only checkbox if it is necessary to work with application code in different platform versions.
Do not select the Cache Assemblies on Local Drive Only checkbox on user workstations if the project's production version is used.
Remove compiled assemblies from the repository before commissioning the system to a customer. Then deselect the Cache Assemblies on Local Drive Only checkbox and start users' forms to compile and save assemblies in the repository. The users' forms must be started with the platform version, which will be also installed at customer's place in the future. This will prevent from compiling objects on deployment and startup of the system because the previously compiled objects are loaded into the file cache from the repository database.
Remember that a modified unit or form is saved when compiled from the development environment. After this it cannot be guaranteed that a previous platform version can open the saved unit or form.
Developed units and forms should be arranged and stored inside the assemblies. This reduces the number of created cache files, which reduces the number of file system calls and speeds up startup of cached objects.
Update installation and editing of cached units is recommended to be executed when there are not active users in the repository. This will prevent unpredictable consequences. After the update is installed or units are edited, it is required to clear cache.

The Cache Assemblies on Local Drive Only checkbox is deselected by default, and the compiled version of object is saved both on the local drive and in the repository. In this case the following issues are possible:

If different platform versions are used to work within the same repository, and the compiled assemblies are saved in the repository, one project can store forms and units compiled by different platform versions. This may cause errors like Access Violation or Internal Runtime Error, that occur, for example, when a form is started from another form compiled by other release of the platform. These errors are caused by incompatibility of formats in different platform versions.
This may slow down development process. On compiling objects on the same computer, their compiled versions are saved in the repository database, and the repository is locked during saving. Other users will have to wait to access to the repository again. If the platform crushes during the saving, the repository may remain locked for other users. In this case it may be necessary to check active sessions, to find and terminate the session, within which the access was locked.
If the object is used at the same time on several computers, local compiled versions and repository versions are compared. This will cause constant detecting of differences, which in turn will overload server because versions are constantly loaded the local drive and unloaded back to the repository database.

To avoid such consequences:

Select the Cache Assemblies on Local Drive Only checkbox at the stage of project development.
Delete complied assemblies from repository.

Cache Clearing

Cache clearing helps avoiding the use of potentially outdated data. Depending on the operating system in use, there are different cache clearing options.

Linux Windows

To delete development environment object cache, delete files in the subfolder opt/foresight/fp10.x-biserver/var/cache/AsmCache<n>/Mod/<repository ID> of the required repository. Cache is cleared by the BI server administrator.

To clear repository cache, select the Tools > Clear Cache item in the object navigator's main menu.

To clear cache of dictionaries and time series databases, click the Clear Cache button on the Cache in the object properties.

To clear regular report cache, click the Clear button in the Object Cache dialog box.

To clear development environment object cache, select the Repository > Clear Assembly Cache item in the security manager's main menu.

To work with cache of various objects in the Fore language, use properties and methods of the IMetabase, IMetabaseObject interfaces. To clear object cache, use the IMetabaseCache.FlushAll method.