Re: VisualDCT not starting on RHEL7

[Andrew Johnson <anj@aps.anl.gov>]

Hi Ralph,

On 12/19/2017 10:32 AM, Ralph Lange wrote:
> On RHEL7 (7.3 and 7.4), VisualDCT immediately quits when configured to
> load DBDs at start.

Have you tried a different DBD file? Loading softIoc.dbd works for me
when it was built by Base-3.14 and 3.15, but not with 3.16 or 7.0.

> What we see:
> Moving our system from RHEL 6 to RHEL 7, the VisualDCT tool doesn’t
> correctly start up anymore. We set the dbd files to read at startup via
> an env variable, and VDCT seems to start up normally, but then bails out
> complaining that it did not load any DBDs:
> $ vdct
> Loading VisualDCT v2.6.1280...
> 
> 
> Directive to load DBD: '/opt/codac-6.0/epics/dbd/base.dbd'.
> Directive to load DBD: '/opt/codac-6.0/epics/dbd/pxi6259.dbd'.
> Directive to load DBD: '/opt/codac-6.0/epics/dbd/nisync.dbd'.
> Directive to load DBD: '/opt/codac-6.0/epics/dbd/nisync-generalTime.dbd'.
> No DBD loaded! Exiting...

Here's what I get with 3.16:

> tux% vdct dbd/softIoc.dbd
> Loading VisualDCT v2.6.1280...
> 
> 
> Directive to load DBD: 'dbd/softIoc.dbd'.
> No DBD loaded! Exiting...

However with 3.15:

> tux% vdct dbd/softIoc.dbd
> Loading VisualDCT v2.6.1280...
> 
> 
> Directive to load DBD: 'dbd/softIoc.dbd'.

and the window opens as expected.

Interestingly even softIocPVA.dbd works when using the earlier Base
releases:

> tux% pwd
> /local/anj/v4/bundleCPP/pva2pva
> tux% vdct dbd/softIocPVA.dbd 
> Loading VisualDCT v2.6.1280...
> 
> 
> Directive to load DBD: 'dbd/softIocPVA.dbd'.

I suspect VDCT doesn't like the link() entries that appeared in 3.16 DBD
files, but whether that's the cause of the crash I don't know. Then
there's the new JSON syntax that we now support in DB files for both
field() and info() statements...

> The DBD files are fine, the same jar that works on RHEL 6 shows this
> behaviour on RHEL 7. Java versions are different, but not that different
> (1.8.0_101 vs. 1.8.0_141).

My machine got patched recently, so my java is newer than either of
yours, but I doubt that's the cause of your crashes:

> tux% java -version
> openjdk version "1.8.0_151"
> OpenJDK Runtime Environment (build 1.8.0_151-b12)
> OpenJDK 64-Bit Server VM (build 25.151-b12, mixed mode)

HTH,

- Andrew

-- 
Arguing for surveillance because you have nothing to hide is no
different than making the claim, "I don't care about freedom of
speech because I have nothing to say." -- Edward Snowdon