Re: Questionable IDS 9.21 performance on HP-UX v11.11

jasondinsdale@bigpond.com (Jason) wrote in message news:<494e6103.0408262219.6784787e@posting.google.com>... > Greetings all, > > We're having severe performance problems with our OLTP Delphi app that > connects to IDS via ODBC. > Having researched the problem I can find no glaring operating system > or database-configuration issues > as such and my suspicion lies firmly with the application itself. > However, I need to eliminate the > O/S and IDS config as a source of the problem, and so I'd be grateful > if you could run you eyes over > the database config and confirm that I'm on the right track. All, Thanks very much for your contributions, AK in particular; I thought I'd post a concluding summary of the tuning activities that I implemented, since we seem to have addressed the majority of our performance problems through a combination of kernel tuning and database tuning. In particular: - max_thread_proc from 256 > 1024 - scsi_max_qdepth from 8 > 32 Since Informix is heavily multi-threaded, and we were leveling off at around 250 db sessions, this looked like a good candidate for tweaking. I also configured the LVM devices and kernel to a SCSI qdepth of 32 (default is 8). I left the FC disk array in AutoRAID mode since the database was definitely NOT I/O bound during the periods of poor performance, and my own benchmarks (using our database and data with 100 *heavy* concurrent sessions and this was definitely I/O bound) indicated a performance hit of only 6%. As far as the database is concerned, the key change was tweaking the NETTYPE parameters so that CPU VPs are used for ipcshm connections, and NET VPs are used for TCP connections (we had the reverse). The other change of note was the reduction of CPUVPS from 4 to 2; seems that CPUVPs 3 and 4 were not doing a great deal apart from contending for resources and making a general nusiance of themselves. Since then the user population seems to have settled down, with a dramatic drop in cursing of the IT dept and/or database server. Sys admin/dba nirvana? Thanks, Jason