Caching Repository Objects

When caching dictionary and dimension elements in time series databases, the system creates temporary copies of object on a user computer that contain element attribute values and links to objects in use.

NOTE. Cache of dictionary and time series database elements is stored and used within one repository connection.

Caching of dictionaries and time series database is intellectual and is available for different users if they have equal access permissions and use equal parameter values. It means that several instances of the same object can be cached (for example, for different parameter values).

Cache allows for speeding up user forms and executing application code on working with application projects.

When units/forms/assemblies (Fore or Fore.NET) are compiled, file cache is created on the local drive, which stores conpiled object version. By default, cache is located in the user profile, in the subdirectory \AppData\Local\Foresight\Foresight Analytics Platform\AsmCache<n>\Mod\<Repository ID>\<assembly number>\. If required, file cache storage path can be changed. To do this, in the key [HKEY_CURRENT_USER\Software\Foresight\Foresight Analytics Platform\9.0\9.2] create the CachefilePath string parameter and set required path in it.

To speed up the first starting of application projects on an commercial scale, compiled objects of development environment 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 in the repository database. This checkbox is located in the Repository Parameters dialog box. On the first start compiled versions of objects are copied to file cache. After that, the rest of the work is executed with file cache.

Possible Consequences

The Cache Assemblies on Local Drive Only checkbox is deselected by default, the compiled version of object is saved both on the local drive and in the repository.

If different platform versions are used to work within the same repository, and the compiled assemblies are saved to 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 also slow down development process. On compiling objects on the same computer, their compiled versions are saved into the repository database. If these objects are used at the same time to work on another computer, 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 loaded back to the repository database.

Solution

To avoid such consequences:

• Select the Cache Assemblies on Local Drive Only checkbox at the stage of project development.

• Delete complied assemblies from the repository.

Recommendations

• On developing application code, select the Cache Assemblies on Local Drive Only checkbox. This will enable you to work with code in different platform versions.

• It is not recommended to select the Cache Assemblies on Local Drive Only checkbox if the system is installed on the users' workstations belonged to a customer.

• 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 also be installed at customer's workstation in the future. This will prevent compiling objects on decompressing and first starting of the system, as the previously compiled objects are loaded into the file cache.

• In order not to prevent users from working in the system, when the system is developed for a customer, it is necessary to select the Cache Assemblies on Local Drive Only checkbox on the workstations used for development.

• 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 are recommended to be arranged and stored inside the assemblies. This reduces the number of created cache files that reduces the number of file system calls and speeds up start of cached objects.

• Selection or deselection of the Cache Assemblies on Local Drive Only checkbox does not slow down general development process, as in any case file cache is used at the start. This checkbox can have influence only on the startup and deploying of a new version of application on customer's computers.

When caching regular reports the system creates instances of the object opened with specific parameter values. Presence of record that corresponds to these parameters in the cache is checked when opening the object with any parameters. If the record is found, it will be extracted and the cached version of the object will be opened. If the record for the specified parameters is not present, the last version of object will be opened in the repository. In this case, all objects, on which it depends, are also opened. Cache of regular report instance is stored in the repository database. Report cache is managed using the Object Cache dialog box.

To speed up map rendering in reports, use map caching. When a report is opened, it is checked if cache contains a map. If a map is found in the cache, the cached map is displayed in the report. If cache does not contain a map, the repository map is opened, and cache is updated.

If there are several connections to the same repository, a common cache with maps is used for all of them. When all connections are closed, map cache is cleared.

When objects in the navigator are displayed as extra large icons, their thumbs are cached. Images caching is used only for reports created in the Dashboards, Analytical Queries (OLAP), Reports, and Time Series Analysis tools.