 25 Jul 2017, Stefan Ritt, Info, Current git repository "develop" branch broken
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Dear all,
we are currently undergoing major modifications in the way mhttpd is working. I realized that
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04 Aug 2017, Konstantin Olchanski, Info, Notes on installing midas from scratch
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Notes on installing midas from scratch. The instruction on midaswiki will be synced with this later.
cd ~/packages
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 07 Aug 2017, Stefan Ritt, Info, Notes on installing midas from scratch
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Thanks for documenting this in detail. A few suggestions:
- is it really necessary to call odbedit three times? Maybe two or even three functions can be merged. Like you call odbinit, it checks if the environment |
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11 Oct 2017, Konstantin Olchanski, Info, added support for ucLinux
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Support for building for ucLinux was added to MIDAS. I use the emcraft toolchain and userland on
some kind of embedded ARM CPU that does not have an MMU. See the Makefile for details. The
main difference of ucLinux is lack of fork(), which cannot be done without an MMU. Not everything
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13 Oct 2017, Konstantin Olchanski, Info, odb multithread support repaired
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multithreaded access to odb was implemented back in 2013-2014. but recently a bug surfaced -
there was a race condition in the odb locking code against cm_watchdog(). Somehow this only
affected the mserver for the DRAGON experiment at TRIUMF. This is now fixed on the branch
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21 Nov 2017, Konstantin Olchanski, Info, MIDAS support on el5?
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It has been reported that the current midas release candidate does not build on el5 linux (SL/RHEL/CentOS-5).
According to Red Hat, el5 is end-of-life, last SL 5 (SL5.11) was done in 2014, so this linux is very old. Also as it happens, I do not have access to any |
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08 Jun 2018, Lee Pool, Info, MIDAS RTEMS PoRT
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Hi,
So I finally got around to "publish" work I did in 2009/2010 with RTEMS.
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20 Jul 2018, Konstantin Olchanski, Info, ROOT I/O workshop notable
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The ROOT I/O workshop was held on June 20th at CERN. A few things of interest in MIDAS land:
- LZ4 is now used as default compression (replacing gzip-1)
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24 Oct 2018, Ryu Sawada, Info, bm_receive_event timeout in ROME
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Hi all
There is a bug report in the ROME repository which says bm_receive_event timeouts.
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22 Nov 2018, Konstantin Olchanski, Info, status of self-signed https certificates
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I just happened to check the current situation with self-signed https certificates as implemented in mhttpd.
(To remember, the powers-that-be are pushing for universal use of https for all web access. The https
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30 Nov 2018, Stefan Ritt, Info, status of self-signed https certificates
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> In the mean time, we continue to recommend that mhttpd should be used behind a password protected https proxy (i.e. apache
> httpd, etc).
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03 Dec 2018, Konstantin Olchanski, Info, status of self-signed https certificates
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> > In the mean time, we continue to recommend that mhttpd should be used behind a password protected https proxy (i.e. apache
> > httpd, etc).
>
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05 Dec 2018, Konstantin Olchanski, Info, Partial refactoring of ODB code
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The current ODB code has several structural problems and I think I now figured out how to straighten them out.
Here is the problems:
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11 Dec 2018, Stefan Ritt, Info, Partial refactoring of ODB code
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All makes sense to me. I agree to proceed with the refactoring.
One additional comment: In the 90's when I developed this code, locking was expensive. On a decent computer you could do a couple of thousand lock operations |
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18 Dec 2018, Konstantin Olchanski, Info, mxml update
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the mxml library was updated to make it thread-safe.
https://bitbucket.org/tmidas/mxml/src/master/
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26 Dec 2018, Konstantin Olchanski, Info, Partial refactoring of ODB code
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> One additional comment: In the 90's when I developed this code, locking was expensive.
> Now the world has changed, we can do almost a million locks a second.
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26 Dec 2018, Konstantin Olchanski, Info, bm_receive_event timeout in ROME
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> There is a bug report in the ROME repository which says bm_receive_event timeouts.
> https://bitbucket.org/muegamma/rome3/issues/8/rome-with-midas-produces-timeout-after
> Does anybody have any ideas what could causing the problem ?
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27 Dec 2018, Stefan Ritt, Info, Partial refactoring of ODB code
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> I am not sure this is quite true. The CPU can execute 3000 million operations per second (3GHz CPU, assuming 1 op/Hz),
> so 1 lock operation is worth 3000 normal operations. Of course cache misses and branch mispredictions mess up
> this simple arithmetic...
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28 Dec 2018, Konstantin Olchanski, Info, note on the midas event buffer code, part 1
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In this technical note, I write down the workings of the midas event buffer code, the path
that events travel from the frontend to the SYSTEM buffer to mlogger (and to disk).
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28 Dec 2018, Konstantin Olchanski, Info, note on the midas event buffer code, part 2, bm_send_event()
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> In this technical note, I write down the workings of the midas event buffer code
> we need to understand and write down how the event buffer code works.
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