Times - Class 3 - Suspensions

Transcription

1 Times - Class 3 - Suspensions This topic shows detailed information about Accounting - Times - Class 3 - Suspensions. This block shows information for Class 3 Suspensions. The following example shows both layouts, the report on the left, and the trace layout on the right. Accounting - Times - Class 3 - Suspensions Report: The field labels shown in the following sample layout of Accounting - Times - Class 3 - Suspensions are described in the following section. Trace: CLASS 3 SUSPENSIONS AVERAGE TIME AV.EVENT CLASS 3 SUSPENSIONS ELAPSED TIME EVENTS LOCK/LATCH(DB2+IRLM) LOCK/LATCH(DB2+IRLM) IRLM LOCK+LATCH IRLM LOCK+LATCH DB2 LATCH DB2 LATCH SYNCHRON. I/O SYNCHRON. I/O DATABASE I/O DATABASE I/O LOG WRITE I/O LOG WRITE I/O OTHER READ I/O OTHER READ I/O OTHER WRTE I/O OTHER WRTE I/O SER.TASK SWTCH SER.TASK SWTCH UPDATE COMMIT UPDATE COMMIT OPEN/CLOSE OPEN/CLOSE SYSLGRNG REC SYSLGRNG REC EXT/DEL/DEF EXT/DEL/DEF OTHER SERVICE OTHER SERVICE ARC.LOG(QUIES) ARC.LOG(QUIES) LOG READ LOG READ DRAIN LOCK DRAIN LOCK CLAIM RELEASE CLAIM RELEASE PAGE LATCH PAGE LATCH NOTIFY MSGS NOTIFY MSGS GLOBAL CONTENTION GLOBAL CONTENTION COMMIT PH1 WRITE I/O COMMIT PH1 WRITE I/O ASYNCH CF REQUESTS ASYNCH CF REQUESTS TCP/IP LOB XML TCP/IP LOB XML ACCELERATOR ACCELERATOR TOTAL CLASS TOTAL CLASS LOCK/LATCH(DB2+IRLM) - AVERAGE TIME/ELAPSED TIME This field depends on the DB2 version that is installed: v DB2 10 or later: The sum of the accumulated wait time due to local contention for locks and the accumulated wait time due to latch contention. v Prior to DB2 10: The accumulated lock and latch elapsed time. Note: The internally defined field adjusts the original DB2 value. DB2 counts each event twice, one for the entry and one for the exit. Field Name: AWTLOLA LOCK/LATCH(DB2+IRLM) - AV.EVENT/EVENTS This field depends on the DB2 version that is installed: v DB2 10 or later: The sum of the number of wait trace events processed for waits for local contention for locks and the number of wait trace events processed for waits for latch contention. v Prior to DB2 10: The number of wait trace events processed for lock/latch. Note: The internally defined field adjusts the original DB2 value. DB2 counts each event twice, one for the entry and one for the exit. Chapter 5. Accounting Default Layouts 5-231

2 Field Name: ADLLSUSC IRLM LOCK+LATCH - AVERAGE TIME/ELAPSED TIME This field depends on the DB2 version that is installed: v DB2 10 or later: The accumulated wait time because of local contention for locks. The term local contention is used to differentiate from global contention (which is reported in QWACAWTJ). Local contention does not require intersystem communication. The contention is detected and resolved entirely within this subsystem. v Prior to DB2 10: The accumulated lock and latch elapsed time. It indicates the elapsed time the allied agent waited for locks and latches in DB2. This value does not include suspensions because of group-level lock contentions in a data sharing environment. When the event completes, the ending time is used to calculate the total elapsed wait time. The result is added to the previously saved lock and latch wait time in DB2. If class 9 is not active, the time shown does not include the time for internal latching. Field Name: QWACAWTL IRLM LOCK+LATCH - AV.EVENT/EVENTS The number of wait trace events processed for waits for local contention for locks. Note: The internally defined field adjusts the original DB2 value. DB2 counts each event twice, one for the entry and one for the exit. Field Name: ADLBSUSC DB2 LATCH - AVERAGE TIME/ELAPSED TIME The accumulated wait time because of latch contention. Field Name: QWACAWLH DB2 LATCH - AV.EVENT/EVENTS The number of wait trace events processed for waits for latch contention. Note: The internally defined field adjusts the original DB2 value. DB2 counts each event twice, one for the entry and one for the exit. Field Name: ADLASUSC SYNCHRON. I/O - AVERAGE TIME/ELAPSED TIME The I/O elapsed time accumulated due to synchronous I/O suspensions. DB2 calculates this value by subtracting the store clock time when an agent begins waiting for a synchronous I/O from the time the agent is resumed. Field Name: ADIOSUST SYNCHRON. I/O - AV.EVENT/EVENTS The total number of synchronous I/O suspensions. Field Name: ADIOSUSC DATABASE I/O - AVERAGE TIME/ELAPSED TIME OMEGAMON XE for DB2 PE & PM: Report Reference

3 The accumulated I/O elapsed wait time for database I/O done under this thread. This field is for synchronous I/O only. It includes synchronous read and write I/O. Field Name: QWACAWTI DATABASE I/O - AV.EVENT/EVENTS The number of wait trace events processed for waits for database I/O under this thread. Field Name: ADIOARNE LOG WRITE I/O - AVERAGE TIME/ELAPSED TIME The accumulated wait time for log write I/O. Field Name: QWACAWLG LOG WRITE I/O - AV.EVENT/EVENTS The number of wait trace events processed for waits for log write I/O. Field Name: ADLWSUSC OTHER READ I/O - AVERAGE TIME/ELAPSED TIME The accumulated waiting time due to a read I/O that performed under a thread other than the one being reported. The time does not represent the total duration of the subject read I/O. It includes: v Sequential prefetch v List prefetch v Sequential detection v Synchronous read I/O performed by a thread other than the one being reported Field Name: QWACAWTR OTHER READ I/O - AV.EVENT/EVENTS The total number of suspensions due to a read I/O performed under a thread other than the one being reported. Field Name: ADARSUSC OTHER WRTE I/O - AVERAGE TIME/ELAPSED TIME The accumulated waiting time due to a write I/O that performed under a thread other than the one being reported. This time does not represent the total duration of the subject write I/O. It includes: v An asynchronous write I/O v A synchronous write I/O performed by a thread other than the one being reported Field Name: QWACAWTW OTHER WRTE I/O - AV.EVENT/EVENTS Chapter 5. Accounting Default Layouts 5-233

4 The total number of suspensions due to a write I/O performed under a thread other than the one being reported. It includes: v An asynchronous write I/O v A synchronous write I/O performed by a thread other than the one being reported. Field Name: ADAWSUSC SER.TASK SWTCH - AVERAGE TIME/ELAPSED TIME The accumulated waiting time due to a synchronous execution unit switching to DB2 services from the thread being reported. It includes: v Open/close data set v SYSLGRNG or SYSLGRNX update v Commit phase 2 for read-only threads originating from TSO or batch v Dataspace manager services v Define data set v Extend data set v Delete data set v Log I/Os for commit and abort processing Special Considerations: 1. A probable cause for high values in this field is data set preformatting. 2. There are no service waits associated with commit phase 2 under read-only threads originating from CICS or IMS. There is a service wait for any thread doing commit phase 2 after an update. 3. There is no overlap between the elapsed time reported in this field and the other class 3 elapsed times. Field Name: ADSTSUST SER.TASK SWTCH - AV.EVENT/EVENTS The total number of suspensions due to a synchronous execution unit switching to DB2 services from the thread being reported. Field Name: ADSTSUSC UPDATE COMMIT - AVERAGE TIME/ELAPSED TIME The accumulated wait time because of synchronous execution unit switch for DB2 Phase 2 commit, abort, or deallocation. This includes wait time for Phase 2 commit Log writes and database writes for LOB with LOG NO. For data sharing environment Page P-locks unlocks for updated pages and GBP writes. Field Name: QWACAWTE UPDATE COMMIT - AV.EVENT/EVENTS execution unit switching for commit or abort. Field Name: ADSTARNS OMEGAMON XE for DB2 PE & PM: Report Reference

5 OPEN/CLOSE - AVERAGE TIME/ELAPSED TIME Accumulated waiting time for a synchronous execution unit switch to the DB2 OPEN/CLOSE data set service for the HSM recall service. Field Name: QWAXOCSE OPEN/CLOSE - AV.EVENT/EVENTS execution unit switching to the open/close service. Field Name: ADOCSUSC SYSLGRNG REC - AVERAGE TIME/ELAPSED TIME Accumulated wait time for a synchronous execution unit switch to the DB2 SYSLGRNG recording service. This service is sometimes used for Level ID checking for downlevel detection. Field Name: QWAXSLSE SYSLGRNG REC - AV.EVENT/EVENTS execution unit switching to the SYSLGRNG recording service. Field Name: ADSLSUSC EXT/DEL/DEF - AVERAGE TIME/ELAPSED TIME Accumulated wait time for a synchronous execution unit switch to the DB2 data space manager services. This includes DEFINE DATA SET, EXTEND DATA SET, DELETE DATA SET, RESET DATA SET, and VSAM CATALOG ACCESS. Field Name: QWAXDSSE EXT/DEL/DEF - AV.EVENT/EVENTS execution unit switching to the data space manager service tasks. Field Name: ADDSSUSC OTHER SERVICE - AVERAGE TIME/ELAPSED TIME The VSAM catalog update. In the distributed environment, it includes the waiting time for the response from the server system. Field Name: QWAXOTSE OTHER SERVICE - AV.EVENT/EVENTS execution unit switching to other service tasks. Chapter 5. Accounting Default Layouts 5-235

6 Field Name: ADOTSUSC ARC.LOG(QUIES) - AVERAGE TIME/ELAPSED TIME The accumulated waiting time due to the processing of ARCHIVE LOG MODE(QUIESCE) commands. This time does not represent the time required to perform the entire command. Field Name: QWAXALOG ARC.LOG(QUIES) - AV.EVENT/EVENTS The total number of suspensions due to the processing of ARCHIVE LOG MODE(QUIESCE) commands. This counter belongs to class 1 (not to class 3 like the rest of the fields in this section) but it is shown here to be adjacent to the archive log quiesce suspension time, which is in class 3. Field Name: ADALSUSC LOG READ - AVERAGE TIME/ELAPSED TIME DB2 V8: The accumulated wait time for: v Archive LOG reads v Active LOG reads v Active LOG prefetch reads Field Name: QWAXAWAR LOG READ - AV.EVENT/EVENTS The number of wait trace events processed for archive reads, active reads, and active log prefetch reads. Field Name: ADLRSUSC DRAIN LOCK - AVERAGE TIME/ELAPSED TIME The accumulated waiting time for a drain lock. This is the time the requester is suspended while waiting to acquire the drain lock. Field Name: QWAXAWDR DRAIN LOCK - AV.EVENT/EVENTS The total number of suspensions due to drain lock processing. Field Name: ADDRSUSC CLAIM RELEASE - AVERAGE TIME/ELAPSED TIME The accumulated waiting time for a drain waiting for claims to be released. After the drain lock is acquired, the drainer must wait for claim holders to release the object. Field Name: QWAXAWCL OMEGAMON XE for DB2 PE & PM: Report Reference

7 CLAIM RELEASE - AV.EVENT/EVENTS The total number of suspensions until the claims are released. Field Name: ADCMSUSC PAGE LATCH - AVERAGE TIME/ELAPSED TIME In the data sharing environment, within the same member, the first thread gets a P-lock (such as: Index leaf page P-Lock or P-Lock for Space map page or data page P-lock for Row level locking). With a high number of concurrent threads, for subsequent threads in the same member for the same resource, contention is reported as encountering a page latch contention. Randomizing the Index key helps minimizing page latch contentions for the Index leaf page, The Member Cluster option reduces page latch contention for a Space map page. Field Name: QWACAWTP PAGE LATCH - AV.EVENT/EVENTS The total number of suspensions due to page latch contentions. Field Name: ADPGSUSC NOTIFY MSGS - AVERAGE TIME/ELAPSED TIME The accumulated elapsed waiting time due to suspensions caused by sending notify messages to other members in the data sharing group. Messages are sent, for example, when the database descriptors are changed due to DDL. Field Name: QWACAWTG NOTIFY MSGS - AV.EVENT/EVENTS The number of suspensions caused by sending messages to other members in the data sharing group. This value is only calculated if accounting class 3 is active and DB2 is a member of a data sharing group. Field Name: ADNOSUSC GLOBAL CONTENTION - AVERAGE TIME/ELAPSED TIME The total accumulated waiting time caused by the suspension of IRLM lock requests due to global lock contention in a data sharing environment that require intersystem communication to resolve. Field Name: ADGCSUST GLOBAL CONTENTION - AV.EVENT/EVENTS The number of suspensions caused by global lock contention. This value is only calculated if accounting class 3 is active and DB2 is a member of a data sharing group. Field Name: ADGCSUSC COMMIT PH1 WRITE I/O - AVERAGE TIME/ELAPSED TIME The accumulated time waiting for phase 1 commit write I/O. An example for this suspension is LOB Table Space with LOG NO Phase 1 commit database synchronous write I/O processing. Chapter 5. Accounting Default Layouts 5-237

8 Field Name: QWAXAWFC COMMIT PH1 WRITE I/O - AV.EVENT/EVENTS The total number of wait trace events for commit phase 1 I/O. Field Name: ADFCSUSC ASYNCH CF REQUESTS - AVERAGE TIME/ELAPSED TIME The accumulated wait time for IXLCACHE and IXLFCOMP requests. Field Name: QWAXIXLT ASYNCH CF REQUESTS - AV.EVENT/EVENTS The number of IXLCACHE and IXLFCOMP asynchronous requests. Field Name: ADIXSUSC TCP/IP LOB XML - AVERAGE TIME/ELAPSED TIME The accumulated wait time for TCP/IP LOB and XML (storing large object and XML) materialization. Field Name: QWACALBW TCP/IP LOB XML - AV.EVENT/EVENTS The number of wait trace events processed for waits for TCP/IP LOB and XML materialization. Field Name: ADLMSUSC ACCELERATOR - AVERAGE TIME/ELAPSED TIME The accumulated wait time for requests to an accelerator. Field Name: QWACAACW ACCELERATOR - AV.EVENT/EVENTS The total number of suspensions due to a request to an accelerator. Field Name: ADAASUSC TOTAL CLASS 3-AVERAGE TIME/ELAPSED TIME The waiting time for all types of class 3 suspensions by the originating task and parallel tasks, if parallelism is employed. Field Name: ADTSUST TOTAL CLASS 3-AV.EVENT/EVENTS The total number of class 3 suspensions. Field Name: ADTSUSC OMEGAMON XE for DB2 PE & PM: Report Reference