> I have noticed a problem with deleting a key to an array in odb, then
> recreating the record as in the code below. The record is recreated
> successfully, but when viewing it with mhttpd, a spurious blank line
> (coloured orange) is visible, followed by the rest of the data as normal.
> 
> db_create_record(hDB,0,"/Equipment/Cycle_scalers/Settings/",strcomb(type1_str));
>     }
>   else {
>     exp_mode = 2; /* TDmusr types - noscans */
>     status =
> db_create_record(hDB,0,"/Equipment/Cycle_scalers/Settings/",strcomb(type2_str));
>   }

The first problem is that the db_create_record has a trailing "/" in the key name 
after Settings. This causes the (empty) subsirectory which causes your trouble. 
Simple removing it fixes the problem. I agree that this is not obvious, so I 
added some code in db_create_record() which removes such a trailing slash if 
present. New version under CVS.

Second, the db_create_record() call is deprecated. You should use the new 
function db_check_record() instead, and remove your db_delete_key(). This avoids 
possible ODB trouble since the structure is not re-created each time, but only 
when necessary.

- Stefan

When using the sequencer to start and stop runs which use a deferred transition,
the sequencer fails with a "Cannot stop run: ..." error.

Checking for the "CM_DEFERRED_TRANSITION" case in the first-pass block of the
'Stop' code in sequencer.cxx is one way to solve the problem - though there may
well be better solutions. 

My edited portion of sequencer.cxx is below.  Is this an acceptable solution
that could be introduced to the master branch?

} else if (equal_ustring(mxml_get_value(pn), "Stop")) {
    if (!seq.transition_request) {
       seq.transition_request = TRUE;
       size = sizeof(state);
       db_get_value(hDB, 0, "/Runinfo/State", &state, &size, TID_INT, FALSE);
       if (state != STATE_STOPPED) {
          status = cm_transition(TR_STOP, 0, str, sizeof(str), TR_MTHREAD |
TR_SYNC, TRUE);
          if (status == CM_DEFERRED_TRANSITION) {
             // do nothing
          } else if (status != CM_SUCCESS) {
             sprintf(str, "Cannot stop run: %s", str);
             seq_error(str);
          }
       }
    } else {
       // Wait until transition has finished
       size = sizeof(state);
       db_get_value(hDB, 0, "/Runinfo/State", &state, &size, TID_INT, FALSE);
       if (state == STATE_STOPPED) {
          seq.transition_request = FALSE;

          if (seq.stop_after_run) {
             seq.stop_after_run = FALSE;
             seq.running = FALSE;
             seq.finished = TRUE;
             cm_msg(MTALK, "sequencer", "Sequencer is finished.");
          } else
             seq.current_line_number++;

          db_set_record(hDB, hKeySeq, &seq, sizeof(seq), 0);
       } else {
         // do nothing
       }
    }
}

Hi,

I'm facing some issues with 'stop' deferred transition and I suspect of
a MIDAS bug regarding this...

to reproduce the issue I use the 'deferredfe' MIDAS example (develop branch), 
changing only the equipment name from 'Deferred' to 'Deferred%02d' in order
to be able to run multiple 'deferredfe' instances;

I run *three* 'deferredfe' frontends using:

./deferredfe -i 0
./deferredfe -i 2
./deferredfe -i 3

Everything goes fine on MIDAS web page and 'deferredfe' frontends are initialized
and ready to run; issues occour after 'start' when I stop the frontends: sometimes
at first shot and sometimes at next 'start'/'stop' the deferred 'stop' transition
seems to be handled in wrong way... and often one frontend goes in 'segmentation fault'

The odd thing is when I run *two* instances: in this case no issues are reported...

Thanks in advance,
Gennaro

Deferred transitions were only implemented with a single instance of a program deferring the 
transition. To have several instances, MIDAS probably needs to be extended. Certainly this 
was never tested, so it's not a surprise that we get a segmentation fault.

Stefan

Hi Stefan,

so if I have two different frontends (feov1725 and feodt5751) connected on the same 'mserver'
I'm in the same situation ?

Cheers,
Gennaro

> Deferred transitions were only implemented with a single instance of a program deferring the 
> transition. To have several instances, MIDAS probably needs to be extended. Certainly this 
> was never tested, so it's not a surprise that we get a segmentation fault.
> 
> Stefan

> I'm in the same situation ?

Yepp.

> Deferred transitions were only implemented with a single instance of a program deferring the 
> transition. To have several instances, MIDAS probably needs to be extended. Certainly this 
> was never tested, so it's not a surprise that we get a segmentation fault.
> 
> Stefan

Hi Stefan,

I copied deferredfe.cxx to mydeferredfe.cxx and I changed mydeferred.cxx to be a different frontend:

const char *frontend_name = "mydeferredfe";

If I start two "different" frontends:

./deferredfe
./mydeferredfe 

and try to start/stop a run... the result is the same: frontend status messing up on next 'start':

---

deferredfe:

Started run 332
Event ID:4 - Event#: 0
Event ID:4 - Event#: 1
Event ID:4 - Event#: 2
Event ID:4 - Event#: 3
Event ID:4 - Event#: 4
Event ID:4 - Event#: 5
Event ID:4 - Event#: 6

mydeferredfe:

Started run 332
Transition ignored, Event ID:2 - Event#: 0
Transition ignored, Event ID:2 - Event#: 1
Transition ignored, Event ID:2 - Event#: 2
Transition ignored, Event ID:2 - Event#: 3
Transition ignored, Event ID:2 - Event#: 4
End of cycle... perform transition
Event ID:2 - Event#: 5
End of cycle... perform transition
Event ID:2 - Event#: 6

---

so, it seems that the issue is not related to different 'instances' of same frontend but
that *at most* one frontend on whole MIDAS server can handle deferred transitions...

is this the case ?

Cheers,
Gennaro 

> so, it seems that the issue is not related to different 'instances' of same frontend but
> that *at most* one frontend on whole MIDAS server can handle deferred transitions...
> 
> is this the case ?


Correct.

- Stefan

We are very happy with the "FILE" implementation of MIDAS history and it is time 
to make it the default for new experiments. This history driver works best if 
"per variable" history is alos enabled. (SQL history already only works in "per-
variable" mode). commit 676051b3024965bd8a04da112965a141d5f61a39
K.O.

I have a problem with using analyzer offline.
I'm trying to do it this way:

[lkst@pklinux online]$ kill_daq.sh
[lkst@pklinux online]$ odbedit -c "load data/run00020.odb"
[ODBEdit,INFO] Reloading RPC hosts access control list via hotlink callback
[lkst@pklinux online]$ analyzer -i data/run00020.mid -o test20.root
Root server listening on port 9090...
Running analyzer offline. Stop with "!"
[Analyzer,INFO] Set run number 20 in ODB
analyzer: src/odb.c:6631: db_paste_node: Assertion `status == 1' failed.
Load ODB from run 20...Aborted
[lkst@pklinux online]$

I always get this "Assertion `status == 1' failed." error even
if I try it in the examples/experiment enclosed in MIDAS distribution.
After this try I can not run any midas program, even odbedit reports an error,
until I delete the ODB file in /dev/shm/ and load last ODB dump with odbedit.
What do I do wrong and how this can be fixed?

> I have a problem with using analyzer offline.
...
> [Analyzer,INFO] Set run number 20 in ODB
> analyzer: src/odb.c:6631: db_paste_node: Assertion `status == 1' failed.

The problem has been traced to unexpected interaction between code in mana.c and 
aggressive error checking in the odb xml decoder (used to load odb.xml dump from the midas 
data file into odb).

We are working on a solution.

K.O.

I am updating TWIST to the latest MIDAS and when I load a saved .odb file, I get
these messages. Their text ought to say where and what strings it does not like.
K.O.



[twistonl@midtwist ~/online]$ odbedit
Please define environment variable 'MIDASSYS'
pointing to the midas installation directory.
[local:twist:S]/>load /twist/data_onl/current/run17548.odb
[odb.c:5600:db_paste] found string exceeding MAX_STRING_LENGTH
[odb.c:5600:db_paste] found string exceeding MAX_STRING_LENGTH
[odb.c:5600:db_paste] found string exceeding MAX_STRING_LENGTH

Can you attach 

/twist/data_onl/current/run17548.odb

so I can reproduce the problem?

I was working on an odb corruption crash inside db_delete_key() and I noticed 
that I did not test db_delete_key() with follow_links set to TRUE. Then I noticed 
that nobody nowhere seems to use db_delete_key() with follow_links set to TRUE. 

Instead of testing it, can I just remove it?

This feature existed since day 1 (1st commit) and it does something unexpected 
compared to filesystem "/bin/rm": the best I can tell, it is removes the link 
*and* whatever the link points to. For people familiar with "/bin/rm", this is 
somewhat unexpected and by my thinking, if nobody ever added such a feature to 
"/bin/rm", it is probably not considered generally useful or desirable. (I would 
think it dangerous, it removes not 1 but 2 files, the 2nd file would be in some 
other directory far away from where we are).

By this thinking, I should remove "follow_links" (actually just make it do thing 
, to reduce the disturbance to other source code). db_delete_key() should work 
similar to /bin/rm aka the unlink() syscall.

K.O.

I would handle this actually like symbolic links are handled under linux. If you delete a symbolic link, the link gets 
detected and NOT the file the link is pointing to.

So I conclude that the "follow links" is a misconception and should be removed.

Stefan

Hi All,

I have found a weird one:

The following code executes on the frontend machine in the
frontend_exit() routine, and connects to the odb running on
another separate machine:
...
     cm_msg(MINFO,__func__, "line %d", __LINE__);

     cm_get_experiment_database(&hdb, NULL);

     cm_msg(MINFO,__func__, "line %d", __LINE__);
     status = db_find_key(hdb, 0, "/Experiment/Run Parameters", &hkey);
     cm_msg(MINFO,__func__, "line %d, hkey=%d, status=%d",
            __LINE__, hkey, status);
     checkstat("db_find_key returned status %d", status);
     cm_msg(MINFO,__func__, "line %d", __LINE__);
     status = db_close_record(hdb, hkey);

     /* NOTREACHED!! the above call to db_close_record
        doesn't return!
      */
     cm_msg(MINFO,__func__, "line %d, status=%d", __LINE__, status);
     checkstat("db_close_record returned status %d", status);

checkstat is a macro that does the following:
#define checkstat(format, arg...)\
do{ if(status != DB_SUCCESS) {\
cm_msg(MERROR, __func__, format, ## arg);\
return FE_ERR_ODB;}}while(0)

The key exists, and the status of the search is 1
(i.e., DB_SUCCESS) and rest of the code tries to run.  What gets
really weird is that the db_close_record _doesn't_ _return_.
The code following the NOTREACHED comment just doesn't get
called.  I get the message from the __LINE__ just in front
of the call, but not the message afterwards (cm_msg and printf 
were tried).  Somehow db_close_record is causing a non-local 
exit or signal or something. No error message is printed and the 
frontend continues to exit with exit code 0.  But, since the rest
of my frontend_exit/odb closing doesn't happen, the odb is left in
a lost state requiring a cleanup.  If I comment out the calls to 
db_close_record, the rest of my frontend_exit runs normally 
and the cm_disconnect_experiment() in mfe.c eventually closes my 
open records correctly (I expect, anyway) and this is the present 
workaround i am using.  The terror i have is that several of my 
hotlinked callback routines will call the close_record routine 
when resetting illegal values.  No end of hilarity will result there...

I was using the same code in the frontend under 1.9.2 and
have only recently upgraded to 1.9.3-? tarball from PAA and 
there were no problems using the 1.9.2 code: this is a 1.9.3
issue.

I have localized the weirdness to what I think is the RPC interface.
Running the nullfrontend (no camac access) on the same machine as 
hosts the ODB I can make the problem appear and disappear in the 
following way:
(odb is local on machine ``monet'')

nullfe -h monet -e acqmonad     : db_close_record will get lost

nullfe -e acqmonad              : db_close_record works as expected.

I've tried also with the patch for the 256 byte odb string bug since
many of the open records have strings of that length, but that isn't
it. The only substancial looking change to mserver from 1.9.2 to 1.9.3
is the SIGPIPE ignore and that doesn't look like a good candidate either.
Can this be that some of the 
   #IFDEF LOCAL_ROUTINES
that got moved about in odb.c and others
are causing the remote call to get confused?

Clearly the answer is to just use stable and happy 1.9.2, but the 
people for whom I am working now really want to use ROOT for
an analyzer...


cheers,
.p.

Paul Knowles.                   phone: 41 26 300 90 64
email: Paul.Knowles@unifr.ch      Fax: 41 26 300 97 47
finger me at pexppc33.unifr.ch for more contact information

Hi Paul,

sorry my late reply, I had to find some time for debugging your problem. 
Thank you very much for the detailed description of the problem, I wish all 
bug reports would be such elaborate!

You were right that there was a bug in the RPC system. The function 
db_remove_open_record() got a new parameter recently, which was not changed 
in the RPC call, and caused the mserver side to crash on any 
db_close_record() call.

I fixed it and the update is under CVS (http://midas.psi.ch/cgi-
bin/cvsweb/midas/src/). Since you need to update many files, I wonder if I 
should enable anonymous CVS read access. Does anybody know how to set this 
up using "ssh" as the protocol (via CVS_RSH=ssh)?

Please note that db_close_record() is not necessary as 
cm_disconnect_experiment() takes care of this, but having it there does not 
hurt.

Hi,

I have been trying to use db_check_record() in order to verify that a subtree in the ODB has the correct 
variables, variable order, and overall size. I'm going off the documentation 
(https://midas.psi.ch/htmldoc/group__odbfunctionc.html) and use a string to compare against the ODB 
structure.  Since the string format is not specified for db_check_record(), I'm formatting my string 
according to the db_create_record() example.

Instead of db_check_record() checking the entire ODB subtree against all the variables represented in the 
string, I'm finding that only the first variable is checked.  The later variables in the string can be 
misspelled, out of order, or inexistent, and db_check_record() will still return 1.

Am I using db_check_record incorrectly?  

Thank you for any help with this issue.


I also believe that some of the documentation for db_check_record is outdated.  For example, init_string 
is referenced in the documentation but isn't part of the function definition.

Dear all

We just started our beam time at ILL and just found yesterday that for certain 
settings of our detector the data is not saved into the .mid files. Running "mdump 
-l 10" online we see the data coming in as they should. Nevertheless, if we run 
"mdump -x runXXXXXX.mid" offline, the data file has no events and the banks are 
missing. Any ideas where the data could go lost?

Thanks in advance,
Ivo

> Dear all
> 
> We just started our beam time at ILL and just found yesterday that for certain 
> settings of our detector the data is not saved into the .mid files. Running "mdump 
> -l 10" online we see the data coming in as they should. Nevertheless, if we run 
> "mdump -x runXXXXXX.mid" offline, the data file has no events and the banks are 
> missing. Any ideas where the data could go lost?
> 
> Thanks in advance,
> Ivo

Have you checked 

/Logger/Channels/0/Settings/Event ID = -1
/Logger/Channels/0/Settings/Trigger mask = -1

If these settings are not -1, they filter the data stream for certain events and trigger 
masks.

Stefan