How to reduce Apptune resource utilization? Why does Apptune trigger early unloads? Why is there an increased zIIP usage with Apptune unloads? How to avoid Apptune early unloads? How to resolve BMC23202 messages? |
How to reduce Apptune resource utilization? These methods can reduce thread and Data Collector utilization, reduce trace volume, and improve reporting responsiveness. Click on each link for additional information. Reduction of thread utilization Reduction of Data Collector utilization Setting collection keys Reduction of trace volume Why does Apptune trigger early unloads? Apptune summarizes data by collection keys. Each collection key specified adds to the reduction table and might increase overhead. It is possible that turning on a certain collection key could generate a large volume of data if the value tends to be unique with each execution of the application. When there is significant increase in data it may trigger an early unload before the scheduled interval. Apptune issues BMC23202 Early unload needed for ssid, entries=count messages with the number of records unloaded. Why is there an increased zIIP usage with Apptune unloads? The Apptune unload executes under an preemptible Enclave SRB and it is 100% zIIP-eligible. Apptune unload activites are asynchronously initiated by the Apptune address space in a dependent enclave that is owned by the Apptune address space. The dependent enclave inherits WLM service class of the Apptune address space. This task is dedicated to building records from SQL performance metrics accumulated in memory and sending them to buffers to be written to the LOGSET log files. The APPTUNE unload enclave SRBs are asynchronous, each dedicated to unloading data for a particular DB2. The amount of data being unload by Apptune correlates directly to increase in zIIP utilization. The collection keys in the APPTUNE filter will have the most significant impact to reduce the volume of data and level of activity by the APPTUNE unload task running on zIIP. Refer to Reduction of Data Collector utilization. How to avoid Apptune early unloads? How to resolve BMC23202 messages? Apptune collection keys and shorter workload intervals can significantly reduce to the volume of entries in the reduction table. Refer to Setting collection keys and Reduction of trace volume. Evaluate the impact of the collections keys on statement entry count using the following example. In this example, the interval has 250,000 entries. A plan has generated over 200,000 entries and there are over 30,000 users executing the plan. In this case, the number of unique users has a great impact than the number of statements executed.
SQMINTVD: SELECT ANALYSIS INTERVAL
+------------------- INTERVAL -----------------+ NUMBER ACTIVE BEGIN END DURATION DB2 ENTRIES FILTER ------------------ ------------------ -------- ---- ------- -------- S 09/09/16 07:55:00 09/09/16 07:58:59 00:03:59 DB01 250000 FILT01
References: Specifying options for a filter option set Collection options Collection keys Resource-saving options Thresholds for exceptions and efficient statements Negative SQL code options Filtering scenarios Collecting data for a specific plan Suppressing collection for specific plans Collecting only exception data Quick Courses Creating and using filters Creating and monitoring exceptions |