IDB2 Experiences slow response times when using cross group active thread panel

Products

• SYSVIEW Performance Management Option for DB2 for z/OS
• Database Management for DB2 for z/OS - SQL Performance Suite

Issue/Introduction

When trying to look at the active threads across the entire DB2B group, picking up the new member on the new LPAR takes a considerably long time (approx 20 seconds) compared to a previously existing member of the group (approx 3 seconds). 

 

 

Environment

Release : 20.0

Component : CA SYSVIEW Performance Management Option for DB2 for z/OS

Resolution

Analysis of the dumps reveals that all the time spent is spent in VTAM code and IDB2 RECEIVE exit, receiving segment after segment of the data. The VTAM LU definitions in the dump shows that the secondary LU has an RUSIZE of 1024. The  number of VTAM RECEIVEs could be reduced by increasing the value of RUSIZE.