 27 Jul 2017, Wes Gohn, Suggestion, Increasing Max Number of Frontends
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Below are the steps we used to increase the maximum number of frontends that we could run.
In midas.h
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 10 Aug 2017, Stefan Ritt, Suggestion, Increasing Max Number of Frontends
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The sizeof checks were originally invented by KO to check for binary compatibility between processes attached to the same ODB and event buffers. So if a
compiler generates different structure sizes due to different padding, one would see that immediately. I wonder however if the absolute numbers make sense |
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12 Aug 2017, Konstantin Olchanski, Suggestion, Increasing Max Number of Frontends
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The checks for byte sizes of critical data structures have been added to ensure (enforce) binary compatibility
of midas with itself on different platforms (32-bit and 64-bit intel, on PPC, on ARM, etc).
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13 Aug 2017, Stefan Ritt, Suggestion, Increasing Max Number of Frontends
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I agree that the binary compatibility checks are crucial. But I kind of find it strange if one gets an assert failure some where if one tries to change
MAX_CLIENTS. It is then not straight
forward to relate both things and understand the consequences. That's why I put a comment next to the definition of MAX_CLIENTS saying:
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13 Aug 2017, Konstantin Olchanski, Suggestion, Increasing Max Number of Frontends
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> if (sizeof(INT) != 4) then severe_error_and_stop_all_programs()
Quick reply.
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13 Aug 2017, Stefan Ritt, Suggestion, Increasing Max Number of Frontends
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The type INT has been defined in 1989 when I for the first time sent data between a 16-bit MS-DOS computer and a 32-bit VAX computer (good old
days!). At that time, uint32_t was not available at all. So much for the historical background.
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06 May 2022, Stefan Ritt, Info, Increased timeout for program shut down
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We had the problem in our lab that a frontend took about 6 seconds to gracefully
shut down, mainly it needed to park some motors. I found that the shutdown command
had a hard-coded timeout of 5 seconds, after which the frontend gets killed, and
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29 Sep 2004, Stefan Ritt, Info, Increased number of clients in midas.h, important!
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Due to some request several limitations like the maximal number of clients to the ODB have
been increased in midas.h and committed to CVS. It is important to note that clients compiled
with the old limits cannot coexist with clients compiled with the new limits. You will get
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03 Oct 2004, Konstantin Olchanski, Info, Increased number of clients in midas.h, important!
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> It is important to note that clients compiled
> with the old limits cannot coexist with clients compiled with the new limits. You will get
> ODB corruption notifications and everything will crash, and you wonder where this comes from.
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03 Oct 2004, Stefan Ritt, Info, Increased number of clients in midas.h, important!
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> Stefan, to avoid confusion from crashes caused by incompatible ODBs would it be possible to add a "version number" to ODB,
together with a check and an error message
> saying "oops... incompatible ODB, please rebuild your programs"? We tend to have different versions of midas floating around and
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03 Oct 2004, Konstantin Olchanski, Info, Increased number of clients in midas.h, important!
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> However, we are planning to make a new release 1.9.5 soon (next week), so can can people tell not to "mix" 1.9.5 with pre-1.9.5 programs.
Right. We cannot fix the past, but we should fix the future. BTW, "do not mix versions" is hard to enforce and mismatches did, do and
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04 Oct 2004, Stefan Ritt, Info, Increased number of clients in midas.h, important!
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> Right. We cannot fix the past, but we should fix the future. BTW, "do not mix versions" is hard to enforce and mismatches did, do and
> will happen
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08 Oct 2004, chris pearson, Info, Increased number of clients in midas.h, important!
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> > For one thing, looking at a given midas-using executable, how do I tell what version of midas it has inside?
>
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08 Oct 2004, Konstantin Olchanski, Info, Increased number of clients in midas.h, important!
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> A lot of programs have a commandline option, such as "--version", where they return the program version number then exit. As well as the
> program version number, the version number of the midas library it's linked with could also be returned (There can be more than one
> libmidas.so on a system and this would show which one was currently being linked)
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20 Sep 2006, Stefan Ritt, Suggestion, Increase of maximum event size
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Dear midas users,
The current event size in midas is limited to 512k (MAX_EVENT_SIZE in midas.h). This is mainly due to old (pre 2.2) linux kernels which had only a very |
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20 Sep 2006, Stefan Ritt, Suggestion, Increase of maximum event size
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Since nobody complained so far, I increased MAX_EVENT_SIZE to 2MB. If anybody has problems with this setting, please report. Note that after updating to
SVN revision 3327 it will be necessary to recompile [U]all[/U] midas programs and to delete any old [B]SYSTEM.SHM[/B] or [B].SYSTEM.SHM[/B]. I added some
code which should check for inconsistent SYSTEM.SHM sizes, but I'm not sure if it works everywhere. |
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27 Sep 2006, Konstantin Olchanski, Suggestion, Increase of maximum event size
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> The current event size in midas is limited to 512k (MAX_EVENT_SIZE in midas.h)
Yes, 512 kBytes is rather small. For the T2K prototype TPC DAQ, I built and ran
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28 Sep 2006, Stefan Ritt, Suggestion, Increase of maximum event size
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[quote="K.O."]Now, we have per-buffer tunable size (see message
https://ladd00.triumf.ca/elog/Midas/283) and in the long run, I would prefer the
compiled-in limit to go away: already all memory is allocated dynamically and
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07 Jun 2017, Alberto Remoto, Forum, Increase MAX_EVENT_SIZE
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Hello,
I am using a CAEN v1720 to digitise signal coming from 5 PMTs and I need to extend the read-
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23 Oct 2008, Konstantin Olchanski, Bug Report, Inconsistent handling of odb and evet buffer timeouts
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In midas.c there are several places where client last activity time stamps are checked against the
watchdog timeout and the clients are declared dead if they fail to update their activity time stamps.
ODB time stamps and data buffer time stamps appear to be handled in a similar manner.
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