SMF 100-230 Global Buffer Pool

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Introduction

DB2 statistics will be collected from SMF type 100. In this type of record, it doesn’t really matter the SMF subtype of the SMF record because DB2 uses another specification type to distinguish different SMF specializations.

In DB2 there is an identification named IFCID (Instrumentation Facility Component Identifier) each one with different data and purpose.

The statistics trace reports information about how much the Db2 system services and database services are used.

You can use the information that the statistics trace provides to plan Db2 capacity or to tune the entire set of active Db2 programs.

If you specify YES for the SMF STATISTICS entry in panel DSNTIPN, the statistics trace uses classes 1, 3, 4, 5, and 6 as the defaults. If the statistics trace is started using the START TRACE command, the statistics trace uses class 1 as the default.

The following table describes the Db2 statistics trace classes.

If you specify YES for the SMFSTAT subsystem parameter, the statistics trace starts automatically when you start Db2, and sends the default classes (classes 1, 3, 4, 5, and 6) statistics data to SMF. SMF records statistics data in both SMF type 100 and 102 records. IFCIDs 0001, 0002, 0202, 0225, 0230, and 0369 are of SMF type 100. All other IFCIDs in statistics trace classes are of SMF type 102.

When you specify CLASS(7) or IFCID(365) in a START TRACE or MODIFY TRACE command, Db2 writes IFCID 0365 records. These records are written to the specified destination of the statistics trace for remote locations that communicate with the subsystem. Statistics are generated only for those locations that have activity since the record was generated. The location statistics are written each time that the STATIME interval elapses. Statistics can be written for as many as 95 remote locations.

Db2 also writes statistics about all DRDA locations with the other default statistics trace data to a single SMF location named DRDA REMOTE LOCS, whenever other default statistics are written.

Statistics trace classesThe following table shows the IFCIDs that are activated for each statistics trace class.Table 1. Classes for Db2 statistics traceClassDescription of classActivated IFCIDs1Information about system services, database statistics, statistics for the database services address space (ssnmDBM1), and information about the system parameters that were in effect when the trace was started. This default class is also activated when you omit the CLASS keyword from the START TRACE command when you start the statistics trace.0001, 0002, 0105, 0106, 0202, 02252Installation-defined statistics record01523Deadlock, lock escalation, group buffer pool, data set extension information, and indications of long-running uncommitted reads, and active log space shortages.0172, 0196, 0250, 0258, 0261, 0262, 0313, 0330, 03374Db2 exceptional conditions.0173, 0191-0195, 0203-0210, 0235, 0236, 0238, 0267, 02685Db2 data sharing statistics record.02306Storage statistics for the Db2 subsystem.02257DRDA location statistics.03658Data set I/O statistics.01999Aggregated CPU and wait time statistics by connection type.036910 - 29Reserved. 30 - 32Available for local use.

Intervals for collecting Db2 statistics trace records
Db2 collects statistics trace records for the following IFCIDs at the interval specified by the STATIME and SYNCVAL subsystem parameters. For more information, see STATISTICS TIME field (STATIME subsystem parameter) and

STATISTICS SYNC field (SYNCVAL subsystem parameter)

0105 (Db2 performance trace)
0106 (system parameters)
0199 (data set statistics)
0365 (remote location statistics)
0402 (monitor profile warnings or exceptions)
Db2 collects statistics trace records for other IFCIDs at fixed one-minute intervals.

CSV I230 for SMF 100 IFCID 230, including PROD section and Global attributes stats.

Fields

Stored in dbsi230

SMF Field DB Column name Description Unit
DBSHD_RTY record_type Value is always I230
DBSHD_SID sid SID
DBSHD_DTTM write_datetime Date/Time written into SMF buffer
DBSHD_SSID ssid Subsystem ID
DBSQWH_QWHSLOCN local_location_name Local location name
DBSQWH_QWHSNID luwid_network_id LUWID Network ID
DBSQWH_QWHSLUNM luwid_luname LUWID LUNAME
DBSQWH_QWHSLUUV luwid_uniquen LUWID UNIQUEN
DBSQWH_QWHSLUCC luwid_commit LUWID COMMIT
DBSQWH_QWHSACE ace_address ACE address
DBSQWH_QWHCAID authorization_id Authorization ID
DBSQWH_QWHCCV correlation_id Correlation ID
DBSQWH_QWHCPLAN plan_name Plan name
DBSQWH_QWHCOPID original_operator_id Original operator ID
DBSQWH_QWHCATYP connection_type Connection type
DBSQWH_QWHCCN connection_name Connection name
DBSQWH_QWHCEUID enduser_id Enduser USER-ID
DBSQWH_QWHCEUTX enduser_transaction Enduser transaction
DBSQWH_QWHCEUWN enduser_workstation Enduser workstation
DBSQWH_QWHCTCXT trusted_context Trusted context
DBSQWH_QWHCROLE role_name Role name
DBSQWH_QWHCCTKN correlation_token Correlation token
DBSQWH_QWHDRQNM requester_location Requester location
DBSQWH_QWHDSVNM server_name_parameter SRVNAM parameter
DBSQWH_QWHDPRID product_id_parameter Product ID parameter
DBSQWH_QWHAMEMN db2_member_name DB2 member name
DBSQWH_QWHADSGN db2_group_name DB2 group name
DBSQWH_QWHUCPU cpu_time_ziip_and_cp CPU time ZIIP+CP
DBSQWH_QWHUSE cpu_time_ziip CPU time ZIIP
DBS230_QBGBGN group_buffer_pool_id Group buffer pool ID
DBS230_QBGBGR1 current_directory_entry Current directory entry or data entry ratio
DBS230_QBGBGR2 pending_directory_entry Pending directory entry or data entry ratio
DBS230_QBGBGCT castout_class_level_threshold Castout class level threshold
DBS230_QBGBGGT group_buffer_pool_level_threshold Group buffer pool level threshold
DBS230_QBGBGAS current_autorec Current automatic recovery (AUTOREC) setting
DBS230_QBGBGCS current_gbpcache Current GBPCACHE setting
DBS230_QBGBGCK group_buffer_pool_checkpoint_interval Group buffer pool checkpoint interval minute
DBS230_QBGBGSZ allocated_size_group_buffer_pool Allocated size of the group buffer pool 4 kilobytes
DBS230_QBGBGDR current_allocated_directory_entries Number of allocated directory entries
DBS230_QBGBGDT current_allocated_data_entries Number of allocated data entries
DBS230_QBGBDRR directory_entry_reclaim Directory entry reclaim counter
DBS230_QBGBDTR data_entry_reclaim Data entry reclaim counter
DBS230_QBGBRXI xi_directory_entry_reclaim Cross-invalidation (XI) directory entry reclaim counter
DBS230_QBGBTCC total_changed Total changed counter
DBS230_QBGBDUP duplex_or_simplex Duplex or simplex indicator
DBS230_QBGBGCTN class_level_castout_threshold Class level castout threshold
DBS230_QBGBSZ2 allocated_size_group_buffer_pool_secondary Allocated size of the duplexed secondary group buffer pool
DBS230_QBGBGDR2 current_allocated_directory_entries_secondary Number of allocated directory entries for the duplexed secondary group buffer pool
DBS230_QBGBGDT2 current_allocated_data_entries_secondary Number of allocated data entries for the duplexed secondary group buffer pool