 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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28 Dec 2018, Konstantin Olchanski, Info, note on the midas event buffer code, part 3, rpc_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.
> bm_send_event() does this ...
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28 Dec 2018, Konstantin Olchanski, Info, note on the midas event buffer code, part 4, reading from event buffer
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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.
> > bm_send_event() does this ...
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02 Jan 2019, Konstantin Olchanski, Info, note on the midas event buffer code, part 5, bm_read_buffer()
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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.
> > > bm_send_event() does this ...
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02 Jan 2019, Konstantin Olchanski, Info, note on the midas event buffer code, part 6, reading events through the mserver
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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.
> > > > bm_send_event() does this ...
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