Direct access to a CAS area
For reliability and performance reasons it is possible to configure more file shares for the same MMC area. File shares can be configured as UNC paths by the property Path to Directory on Server (COOSYSTEM@1.1:darearemdir). If file shares are configured the Fabasoft Folio Kernel reads and writes all contents from the shares without the Fabasoft Folio MMC Service.
When the Fabasoft Folio Kernel reads a content, the file access occurs on a randomly selected file share. (Load distribution). If the content cannot be found on one share another share is selected. (Reliability)
When writing contents the Fabasoft Folio Kernel writes parallel to all configured file shares. The transaction is successful when at least on 50 percent of the configured shares the write operation succeeded.
- File servers must process write requests synchronously or honor filesystem synchronization requests to prevent data loss. In case of Samba (CIFS), the server option strict sync = yes is required. In case of Linux/nfsd (NFS), the export option sync is required.
- The user context in which the Fabasoft Folio Kernel is running (e.g. Web Service User) must have read and write privileges on the configured shares.
- On Linux systems, the configured UNC paths will be resolved automatically based on currently mounted filesystems.
- Changing the MMC area configuration requires the execution of “Synchronize Registry Entries”.
- Changing the MMC area configuration requires a restart of the kernel.
- The number of writer threads can be configured via the environment option MMCWRITETHREADCOUNT and is 12 by default.
- For each Fabasoft Folio Kernel a preferred read share can be configured via the environment option MMCREADDIR_<areaname> (e.g. MMCREADDIR_MMCSVC1 = "\\192.168.100.100\CAS2").