[Info-vax] What choices are available to the OpenVMS Process Scheduler once all the CPUs are in use?

[Bob Gezelter]

On Thursday, February 11, 2016 at 12:26:04 PM UTC-5, Stephen Hoffman wrote:
> On 2016-02-11 04:28:22 +0000, sean at obanion.us said:
> 
> > There was an application code change in the middle of Dec., and we 
> > included the OpenSSL patch, and have found the CUR Queue change from 
> > that date.
> > 
> > Regarding OpenSSL, we believe that Cache is using the OpenSSL libraries 
> > for encryption.There are several hundred processes communicating to a 
> > number of internal servers that are using AES encryption that we may 
> > take to no encryption and move to an isolated, non-routing subnet on 
> > our testing system. The other application code changes are being 
> > evaluated.
> 
> Seems your applications and/or SSL and/or something else that changed 
> here has caused your already-pretty-busy system to become more-busy.
> Get some T4 data collections going, and see what that shows for trends.
> Unfortunately, looking at the scheduler is not going to get you more computes.
> Probably time to start figuring out what to tune and what to upgrade, 
> if your current trends are increasing or if your expected load will be 
> increasing.
> That might be the server, or maybe an SSL offload, or some other detail 
> that the T4 and related data might point to.   Or the box is just too 
> busy.
> 
> 
> -- 
> Pure Personal Opinion | HoffmanLabs LLC

Sean,

I find it interesting that with 32 processes CUR and 120 COM, the CPU is reported only 20% busy (I presume that includes all modes; I could easily believe that only 20% was User mode).

As Hoff noted, the complete T4 data gathering on an actual system in this state would likely be illuminating.

- Bob Gezelter, http://www.rlgsc.com