> When I run odbedit remotely (odbedit -h ladd09), the "cleanup" command unexpectedly produces the 
> output of the "sor" command (sure enough, there is a call to db_get_open_records() there), but when I run 
> it locally, I do not get this output (but db_get_open_records() is still called). Strange. K.O.

The db_get_open_records() call was by mistake there, I removed it. What remains is that the notification 
message if a client is removed from the ODB goes through the system messages. When running locally, odbedit 
echoes it's own messages, but when running remotely, this is not the case. So the messages can be seen by 
everybody else (plus it ends up in the message file), but not by the remote odbedit where the cleanup is 
started. The quick fix for that is to say "old" in odbedit which shows the last few lines of the message 
file, so one can see any successful cleanup. 

> A new set of functions was added to mscb.h to adjust mscb timeouts and retries to better match specific 
> applications:
> 
> +   int EXPRT mscb_get_max_retry();
> +   int EXPRT mscb_set_max_retry(int max_retry);
> +   int EXPRT mscb_get_usb_timeout();
> +   int EXPRT mscb_set_usb_timeout(int timeout);
> +   int EXPRT mscb_get_eth_max_retry();
> +   int EXPRT mscb_set_eth_max_retry(int eth_max_retry);

In the spirit of this, a variable retry scheme has been implemented in the mscbdev.c device driver. At the 
MEG experiment, we have one mscb device which is pretty slow, while the others are fast. Therefore it is 
necessary to have a per-device max retry count which can be different for different submasters. I moved 
therefore the max_eth_retry variable into the mscb_fd structure and adjusted a few functions accordingly. I 
did not bother with the other timeouts and retries, since I don't need this for the moment, but it would be 
nice if they would be handled in the same way. Then I added code into mscbdev.c to read the retry variable 
form the ODB under /Equipment/<name>/Settings/Device/<Name>/Retries. The default is 10, but it can be 
changed and becomes valid after the program has been restarted. 

To fix this problem, do the following:

- Update to the current SVN revision 4368 of mhttpd.c
- Add following tag into your custom page:

  <input type=hidden name="redir" value="name">

  where "name" is the name of your custom page which follows the CS/ in the URL. Like 
if you have a custom page which you access through httpd://localhost/CS/junk then the 
tag would be 

  <input type=hidden name="redir" value="junk">

The "redir" parameter is now evaluated inside mhttpd and brings you back to the proper 
custom page. You can also define another custom page as the target, if that makes 
sense in your application.

Pierre: Would be nice to document this somewhere more officially.

> Not sure if this is a bug or a feature:
> 
> Writing a boolean label on an image seems to produce rather strange behaviour.
> 
> For example,
> odb>ls /Equipment/gas/settings/my_bool -lt
> Key name                        Type    #Val  Size  Last Opn Mode Value
> ---------------------------------------------------------------------------
> my_bool                         BOOL    1     4     14m  0   RWD  y
> 
> 
> odb>cd /custom/images/my_image.gif/labels
> odb>ls
> Src                             /Equipment/gas/settings/my_bool
> Format                          val: %d (bool)
> Font                            Medium
> X                               10
> Y                               10
> Align                           0
> FGColor                         FFFFFF
> BGColor                         FF8800
> 
> Instead of the expected string "val: y (bool)", only the value of the key
> appears, i.e. "y". 
> The behaviour is the same whether I use %d, %u, %s, %c etc as the format character. 

That has been fixed in rev. 4379

> When writing custom webpages, it would be nice to be able to write code such as
> 
> <odb src="/Equipment/TITAN_ACQ/ppg cycle/trans3/time offset (ms)" edit=1>
> 
> from Javascript, e.g.
> <script  type="text/javascript">
> if ( flag != 3)
>    document.write('<odb src="/Equipment/TITAN_ACQ/ppg cycle/trans3/time offset
> (ms)" edit=1>ms');
> else
>    document.write('<odb src="/Equipment/TITAN_ACQ/ppg cycle/trans4/time offset
> (ms)" edit=1>ms');
> </script>
> 
> This is not translated correctly by mhttpd; the final quote and bracket get
> stripped off, and it gives Javascript error
> 
>  Error: unterminated string literal
> Source File: http://titan04:8089/CS/ppg_cycle?cmd=Edit&index=11
> Line: 477, Column: 18
> Source Code:
>    document.write('<input type=text size=10 maxlength=80 name=value value="1">
> 
> I can get round this by using an input box and a combination of ODBGet and
> ODBSet, but it would be easier if the edit=1 form above worked correctly, or
> there was a command like ODBSet that would accept input from the user.
> 
> Thanks.
> 
>  would be nice is there was a command such as ODBGet or ODBSet that would work
> with javascript to 

Actually that won't work, even if I would fix it. The <odb> tag is evaluated on the
server side (mhttpd), where is gets replaced by the actual ODB value. But if you
use JavaScript to generate the <odb> tag dynamically, this only happens on the
client side, so the server has no chance to substitute them. So you have to go with
ODBGet's I'm afraid. Nevertheless, I changed the code such that any ODB tags inside
a JavaScript is not interpreted by mhttpd.

> Thanks Stefan. 
> Your fix works nicely with the start/stop buttons not returning to the same or to a
> different web page.
> 
> However, it does not seem to have fixed the problem with the Customscript button. It does
> not seem to pick up the redirect, nor do the Pause/Resume buttons (which are programmed to
> appear when the run starts).

That has been fixed in rev. 4377

> Dear All,
> 
> Is there any recommended platforms for running MIDAS? Have anyone encountered 
> problems when running MIDAS on Scientific Linux?
> 
> Thanks.
> 
> Jimmy

I run MIDAS on scientific Linux 5.1 without any problem.

> We have a temperature/humidity sensor in MIDAS now and will add a liquid level 
> sensor to MIDAS soon. We want the operators to get alerted ASAP when the 
> laboratory environment or the liquid level reached some critical levels. Can 
> MIDAS send email alerts or SMS alerts to cell phones when the alarms are 
> triggered? If yes, how can I config it?

Sure that's possible, that's why MIDAS contains an alarm system. To use it, define 
an ODB alarm on your liquid level, like

/Alarms/Alarms/Liquid Level
Active	                 y
Triggered	         0 (0x0)
Type	                 3 (0x3)
Check interval	        60 (0x3C)
Checked last	1227690148 (0x492D10A4)
Time triggered first	(empty)
Time triggered last	(empty)
Condition	        /Equipment/Environment/Variables/Input[0] < 10
Alarm Class	        Level Alarm
Alarm Message	        Liquid Level is only %s

The Condition if course might be different in your case, just select the correct 
variable from your equipment. In this case, the alarm triggers an alarm of class 
"Level Alarm". Now you define this alarm class:

/Alarms/Classes/Level Alarm
Write system message	y
Write Elog message	n
System message interval	600 (0x258)
System message last	0 (0x0)
Execute command	        /home/midas/level_alarm '%s'
Execute interval	1800 (0x708)
Execute last	        0 (0x0)
Stop run	        n
Display BGColor	        red
Display FGColor	        black

The key here is to call a script "level_alarm", which can send emails. Use 
something like:

#/bin/csh
echo $1 | mail -s \"Level Alarm\" your.name@domain.edu
odbedit -c 'msg 2 level_alarm \"Alarm was sent to your.name@domain.edu\"'

The second command just generates a midas system message for confirmation. Most 
cell phones (depends on the provider) have an email address. If you send an email 
there, it gets translated into a SMS message.

The script file above can of course be more complicated. We use a perl script 
which parses an address list, so everyone can register by adding his/her email 
address to that list. The script collects also some other slow control variables 
(like pressure, temperature) and combines this into the SMS message.

For very sensitive systems, having an alarm via SMS is not everything, since the 
alarm system could be down (computer crash or whatever). In this case we use 
'negative alarms' or however you might call it. The system sends every 30 minutes 
an SMS with the current levels etc. If the SMS is missing for some time, it might 
be an indication that something in the midas system is wrong and one can go there 
and investigate.

> I also changed ss_file_size(), ss_disk_size() and ss_disk_free() to return -1 if
> the system call returns an error. I also added a test program
> utils/test_ss_file_size.c.

The test program gave under 64-bit SL5:

For [(null)], file size: -1, disk size: -0.001, disk free -0.001
sh: -c: line 0: syntax error near unexpected token `('
sh: -c: line 0: `/bin/ls -ld (null)'
sh: -c: line 0: syntax error near unexpected token `('
sh: -c: line 0: `/bin/df -k (null)'

Anyhow I guess that this test program just accidentally slipped into the repository.
Test programs for the developers should not be in the repository since they are of
not much use for the average user. If I would have added every test I made as an
individual test program, we would by now have tons of test programs making the whole
distribution pretty bulky, which nobody would know how to use now. So I removed the
test program again. If people do not agree, I suggest to make a central "main" test
program which combines all tests. I know there are also some C structure alignment
tests etc., which then could all be combined into a single, well documented, test
program.

> I now fixed this problem by using the stat64() system call for "#ifdef OS_LINUX".

That does not work if _LARGEFILE64_SOURCE is not defined. In that case, the compiler 
complains that stat64 is undefined. Since many Makefiles for front-ends out there do 
not have _LARGEFILE64_SOURCE defined, I changed system.c so that stat64 is only used 
if that flag is defined:

#ifdef _LARGEFILE64_SOURE
   struct stat64 stat_buf;
   int status;

   /* allocate buffer with file size */
   status = stat64(path, &stat_buf);
   if (status != 0)
      return -1;
   return (double) stat_buf.st_size;
#else
   ...

> How can I add a button at the top of the "Status" webpage which will show a 
> page similar to the "CNAF" one after I click on it? and how can I make a 
> custom page similar to "CNAF" which allow me to call some custom funtions? I 
> want to make a page which is particularly for doing calibration.

The CNAF page calls directly functions through the RPC layer of midas, which is 
not possible from custom pages. All you can do is to execute a scrip on the 
server side, which then causes some action. For details please consult the 
documentation.

> The following error has been reported to me by T2K colleagues:
> 
> When using  "odbedit -c "msg my_message", the following behavior 
> has been observed depending on the length "n" of the message. 
> 
> 1)  n < 100        All is well
> 2)  100 <= n < 245 Log not written but exit code = 0
> 3)  245 <= n < 280 Error: "Experiment not defined" and exit code = 1
> 4)  280 <= n       Error: "Cannot connect to remote host" and exit code = 1
> 
> Also, when logging from compiled C code - when messages reach some magic length
> the MIDAS client sending them segfaults.
> 
> Please fix

Uhhh, who wants this long messages? You should consider to split this into several 
smaller messages. Anyhow, having the above behavior is not good, so I fixed it in 
SVN revision 4422. I increased the maximum length to 1000 characters. Above that, 
the message gets truncated. If you need even more, we can make it a #define.

The second problem you describe (logging from compiled C code) I could not 
reproduce, so maybe it was related to the first one. Please try again and report 
if it persists.

> Hi,
> 
> I am running Scientific Linux with kernel 2.6.9-34.EL and  I have
> glibc-2.3.4-2.25. When I run mlogger, I receive the error:
> 
> *** glibc detected *** free(): invalid pointer: 0x0073e93e ***
> Aborted
> 
> Any ideas?

Not much. Try to clean up the ODB (delete the .ODB.SHM file, remove all shared 
memory via ipcrm) and run again. I run under kernel 2.6.18 and glibc 2.5 and this 
problem does not occur. If you cannot fix it, try to run mlogger inside gdb and 
make a stack trace to see who called the free().

> Sorry for being vague. I cleaned up the ODB, but it doesn't seem to be the
> problem. Here is a sample run of mlogger and gdb:

Thanks for the info, that explained the problem. It is related to the lines

rargv[rargc] = (char *)malloc(3);
rargv[rargc++] = "-b";

where one first allocates some memory (3 bytes), but then overwrites the pointer with 
another pointer to some static memory ("-b"). The following

free(rargv[1]);

then tries to free the static memory which fails.

The problem was already fixed some time ago, so please update your version from the SVN 
revision (see https://midas.psi.ch/download.html for details).

The UDP connection you mention is only used locally for inter-process communication. When I implemented that, I 
made extensive tests and found that there is never a packet being dropped. This happens for UDP only if the packet 
goes over a physical network. Maybe this is different in modern Linux versions, so one should double check this 
again.

For remote hot-link notification, the notification is sent over the TCP link, so it should not be lost either. But 
your second point is correct. The hot-link mechanism was developed to change parameters in front-end programs for 
example. So by design it is guaranteed that if you change a value in the ODB, any client hot-linked to that will 
see the change (sooner or later). If there are many changes in short intervals (or the callback function on the 
remote client takes long time), only the last change is guaranteed to arrive. Therefore, as you correctly state, 
the hot-link mechanism is not a save replacement for the RPC layer (That's why the RPC layer is there after all).

• Set /Channels/x/Settings/Subrun Byte limit to the number of bytes for a subrun
  
• Set /Channels/x/Settings/Filename to something like run%05d_%02d.mid. The first %05d gets replaced by the run number, while the second one gets replaced by the subrun number. This will result in files such as

  run00001_00.mid    run #1
  run00001_01.mid      "
  run00001_02.mid      "
  run00001_03.mid      "
  run00002_00.mid    run #2
  run00002_01.mid      "
  run00002_02.mid      "
  run00002_03.mid      "

Hi,

your log script sound to me like the analyzer either got into an infinite loop or 
did a segment violation and just died. I would recommend to run the analyzer from 
inside the debugger. When you then get the segment violation, you can inspect the 
stack trace and see where the bad things happen. Since the analyzer works nicely in 
other experiment, I expect that your problem is related to the user code. Maybe it 
happens at the end of the run, but there is a timeout before the crashed process 
gets cleaned from the ODB, that's why you might think that it happens "between" 
runs.

Best regards,

  Stefan

> 
> Hello Midas experts:
> 
> We have setup a DAQ using MIDAS to readout two ADCs in the crate.
> We are running into problem of analyzer getting killed between 
> runs.  Sometimes it would crash after a few runs and sometimes it 
> would go on for many many runs before analyzer gets killed.  It always 
> occurred between runs not when we are taking data.  Any suggestions 
> on what we could try?  The error message from the midas.log file is 
> appended below.
> 
> Thanks,
> 
> Dawei
> 
> Wed Mar  4 11:53:11 2009 [Analyzer,ERROR] [midas.c:1739:,ERROR]
> cm_disconnect_experiment not called at end of program
> Wed Mar  4 11:53:22 2009 [mhttpd,INFO] Client 'Analyzer' on buffer 'SYSMSG'
> removed by cm_watchdog (idle 10.7s,TO 10s)
> Wed Mar  4 11:53:22 2009 [mhttpd,INFO] Client 'Analyzer' (PID 1) on buffer 'ODB'
> removed by cm_watchdog (idle 10.7s,TO 10s)
> Wed Mar  4 11:53:22 2009 [AL Experiment Frontend,INFO] Client 'Analyzer' on
> buffer 'SYSTEM' removed by cm_watchdog (idle 10.9s,TO 10s)
> Wed Mar  4 11:53:29 2009 [AL Experiment Frontend,TALK] starting new run
> Wed Mar  4 11:53:29 2009 [AL Experiment Frontend,ERROR]
> [midas.c:8264:rpc_client_check,ERROR] Connection broken to "Analyzer" on host
> tsunami