Use the CF Data Sharing OSAM Details attributes to create table views, charts, and situations that monitor coupling facility characteristics for VSAM cache structures and OSAM cache structures.
CF Blocks Invalidated The number of blocks invalidated in the Coupling Facility cache structure due to Buffer Invalidate calls. Valid format is an integer.
CF Blocks Not Read The number of database blocks not read, because data was not available. Valid format is an integer.
CF Blocks Not Written The number of database blocks that were not written to the cache structure, because the storage class is full. This is an indication that 1) the cache structure sizes need to be tuned or moved to another Coupling Facility, 2) you might need to add memory to the Coupling Facility, or 3) an internal coupling facility error occurred. Valid format is an integer.
CF Blocks Read The number of database blocks that have been successfully read from the Coupling Facility into the OSAM subpools on behalf of IMS application reads. Valid format is an integer.
CF Buffer Entries The number of buffer entries in each OSAM subpool, which requires one buffer list entry for each 2K of subpool buffer space to accomplish OSAM data caching. Valid format is an integer.
CF Buffer Segments The number of 256 byte segments in the Buffer Entry. Valid format is an integer.
CF CACHE Option The option of having ALL subpools containing OSAM buffers cached or having only the CHANGED subpools cached.
If you specify Cache Only Changed Data,and an application program modifies data in a subpool, the CHANGED data is first written to DASD and then to the Coupling Facility.
If you select Cache All Data and an application program requests data that is not already in a subpool or in the Coupling Facility, that data is either read from DASD or copied from the Sequential Buffering buffer into the subpool and then written to the Coupling Facility. The Cache Only Changed Data results in better performance. Valid format consists of up to eight alphanumeric characters.
CF Changed Blocks Written The number of changed blocks written to the Coupling Facility cache structure, due to application database updates when the cache CHANGED buffers option is selected. The combination of Primary Blocks Written and Changed Blocks Written may determine that many blocks are cached that have not been updated. Valid format is an integer.
CF Element Size The size for the Coupling Facility, currently 2K. Valid format is an integer.
CF Primary Blocks Written The total number of primary blocks that are written to the Coupling Facility cache structure due to application reads when the ALL buffer option has been selected. Valid format is an integer.
CF Reclaim Calls The number of CF Reclaim Vector calls (this number is no longer used by IMS because IMS does not use Storage Classes now). If this number appears to be valid, you may need an IBM APAR that removed IMS's use of Storage Class. Valid format is an integer.
CF Storage Class The number of like-sized buffers that make up the subpool. The most recent versions of IMS assign all buffers to the same Storage Class. Valid format is an integer.
CF Successful Calls The number of successful Buffer Invalidate calls. These (XI) calls tell the Coupling Facility to notify all other connectors that the buffer in the cache is now invalid and their local buffers need to be refreshed. Valid format is an integer.
Directory Ratio The numbers specified on the CFNAMES control statement. The Coupling Facility uses these numbers to construct the OSAM cache structure. After the cache structure is allocated, it is divided into directory entries and data element entries. The two taken together show the average number of data elements per directory entry. This ratio can cause IMS to steal old directory or element entries during structure rebuild, which may in turn, cause performance problems. Valid format is an integer.
Element Ratio Specified on the CFNAMES control statement. The Coupling Facility uses the element ratio and the directory ratio to construct the OSAM cache structure. After the cache structure is allocated, it is divided into directory entries and data element entries. The two taken together show the average number of data elements per directory entry. If this ratio is incorrect for an environment s use of the structure, frequent rejections of cache requests can occur. Valid format is an integer.
IMSID The IMS Subsystem identifier. Valid format consists of up to four alphanumeric characters. Example: I61A
Mapping Version An internal column used to indicate the mapping version of the data row. Valid format is an integer.
MVS System The MVS System Management Facility (SMF) identifier. Valid format consists of up to four alphanumeric characters. Example: SP11
Originating System Identifier Fully identifies the originating IMS subsystem. Valid format consists of up to 32 alphanumeric characters. Example: I91A:SP22:IMS
Subpool Buffer Size The block size of the OSAM buffer pool. A subpool can consist of many buffers. All subpools are assigned to the same coupling facility storage class. Valid format is an integer.
Sysplex Identifier Indicates the originating sysplex for this request. Valid format consists of up to eight alphanumeric characters.
Timestamp The date and time when the monitoring agent retrieved the data. This attribute is intended for logging and reporting data collection times rather than for creating situations. To specify a time of day for monitoring, use attributes from the Universal Time or Local Time groups. See the Tivoli Enterprise Portal help for instructions on specifying timestamp attributes in situations and queries.