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    Reply  03 Oct 2004, Stefan Ritt, Info, Increased number of clients in midas.h, important! 
> 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
users have old executables stashed away, 
> and all this makes it rather difficult to manually keep track on what ODB is compatible with what midas.

I fully agree that a version number in ODB is a good thing, and I certainly will put one there, but this won't help for old
applications. If I add new code which checks in cm_connect_experiment() if the version number matches, this will only help for new
applications connecting to old ODBs. If old applications (prior to invention of the version number) connect to a new ODB, they still
will crash.

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.
    Reply  03 Oct 2004, Konstantin Olchanski, Info, Increased number of clients in midas.h, important! 
> 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
will happen. For one thing, looking at a given midas-using executable, how do I tell what version of midas it has inside?

K.O.
    Reply  04 Oct 2004, Stefan Ritt, Info, Increased number of clients in midas.h, important! 
> 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

For remote connections (through mserver), there is already a version check. If the minor version differs, you get a warning, if the major
versions differ (1.>>9<<.4), the client won't start. So at least for remote connection you get a clue.

> For one thing, looking at a given midas-using executable, how do I tell what version of midas it has inside?

Ther is a function cm_get_version() returning the version. As for the executable, all you can do is a

strings <executable> | grep 1.9
    Reply  08 Oct 2004, chris pearson, Info, Increased number of clients in midas.h, important! 
> > For one thing, looking at a given midas-using executable, how do I tell what version of midas it has inside?
> 
> Ther is a function cm_get_version() returning the version. As for the executable, all you can do is a
> 
> strings <executable> | grep 1.9

   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)

   Something I would find useful would be for the version number to identify precisely which version you have, i.e. not to have different
versions of midas given the same version number.  I've had problems earlier this year due to midas-1.9.3 changing several times between
January and July, while keeping the same number.  I think if "in-between" versions of midas are to be made available, they should contain a
revision number or date or something in the version number to identify them.

> For remote connections (through mserver), there is already a version check. If the minor version differs, you get a warning, if the major
> versions differ (1.>>9<<.4), the client won't start. So at least for remote connection you get a clue.

   Safety measures like these can sometimes get in the way, if you know what you're doing.  So unless there is absolutely no possibility of
success, I think checks such as this one should be overrideable (by a client option).

Chris
    Reply  08 Oct 2004, Konstantin Olchanski, Info, Increased number of clients in midas.h, important! 
>    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)

This would solve the versioning problem for midas built from versionned tarballs, and I am considering a similar scheme for midas installed from
RPMs. But what do I do for midas built from CVS?!? K.O.
Entry  20 Sep 2006, Stefan Ritt, Suggestion, Increase of maximum event size 
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 limited shared memory pool. These days this limit has increased considerably and I question if we should increase the default event size and to which size we should increase it.

The drawback of a larger event size is that the SYSTEM event buffer has to hold at least two events, and when the last midas program is stopped or started, this buffer has to be written to or read from the .SYSTEM.SHM file, which slows down the start/stop of the program. But writing/reading a few MB is fast these days anyhow so this again might now be a big problem. So what do you think how big we should make the default max event size?

- Stefan
    Reply  20 Sep 2006, Stefan Ritt, Suggestion, Increase of maximum event size 
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 all midas programs and to delete any old SYSTEM.SHM or .SYSTEM.SHM. I added some code which should check for inconsistent SYSTEM.SHM sizes, but I'm not sure if it works everywhere.
    Reply  27 Sep 2006, Konstantin Olchanski, Suggestion, Increase of maximum event size 
> 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
MIDAS with 4 MByte events, and it worked fine.

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
the MAX_EVENT_SIZE is only useful as kind of a sanity check against frontend
misconfiguration or against malformed events.

If MAX_EVENT_SIZE goes away, the maximum event size becomes limited by the
largest SysV shared memory segment permitted by Linux (via sysctl kernel.shmmax).

To go beyound the limit on SysV shared memories, on can use mmap() based shared
memory: this is limited by available RAM+swap (and disk space for the
.SYSTEM.SHM file). Current MIDAS system.c has an experimental implementation of
mmap() shared memory, but AFAIK it has not been used in any production system, yet.

K.O.
    Reply  28 Sep 2006, Stefan Ritt, Suggestion, Increase of maximum event size 

K.O. wrote:
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
the MAX_EVENT_SIZE is only useful as kind of a sanity check against frontend
misconfiguration or against malformed events.

If MAX_EVENT_SIZE goes away, the maximum event size becomes limited by the
largest SysV shared memory segment permitted by Linux (via sysctl kernel.shmmax).

To go beyound the limit on SysV shared memories, on can use mmap() based shared
memory: this is limited by available RAM+swap (and disk space for the
.SYSTEM.SHM file). Current MIDAS system.c has an experimental implementation of
mmap() shared memory, but AFAIK it has not been used in any production system, yet.


MAX_EVENT_SIZE is also used for the RPC layer, since the receiving buffer must hold at
least one event. It is right that this can and should be made dynamically. Concerning
the shared memory there is the problem that it cannot be increased when any program is
running and attached to the shared memory, so it can only be defined at startup of the
first program creating the shared memory.

The sanity check in the frontend is done against max_event_size defined in frontend.c which can be smaller than MAX_EVENT_SIZE (some front-ends have limited memory).

So I agree that this issue may need revision, maybe something for me next visit Wink
Entry  07 Jun 2017, Alberto Remoto, Forum, Increase MAX_EVENT_SIZE 
Hello,

I am using a CAEN v1720 to digitise signal coming from 5 PMTs and I need to extend the read-
out window to 1ms.

Given the sampling frequency of 250 MHz, each event would consist of about 4.78 MB

Accordingly to the documentation I found in:

https://midas.triumf.ca/MidasWiki/index.php/Event_Buffer

 - I modified the value of ODB /Experiment/MAX_EVENT_SIZE to 8 MB (I overestimated it in case 
I will readout all 8 channels of the v1720)
 - I modified the ODB key /Experiment/Buffer Sizes/SYSTEM to 512 MB (which allow to contain 
about 100 events in the buffer)

The max_event_size in the frontend source code is set to 32 MB while the event_buffer size is 
200 times the max_event_size. So I did not modify those values.

When I start a new run, the MIDAS crash and the ODB gets corrupted:

$ odbedit 
[ODBEdit,ERROR] [odb.c:1134:db_open_database,ERROR] Different database format: Shared 
memory is 262148000, program is 3
[ODBEdit,ERROR] [midas.c:2157:cm_connect_experiment1,ERROR] cannot open database
Unexpected error #326

Do you have any idea of what might be the problem?

The same thing happen if I reduce the buffer size to 128 MB.

The computer running MIDAS has 2 Quad CPU @ 2.83GHz and 4 GB RAM.

Thank you in advance for any help!
Alberto
Entry  23 Oct 2008, Konstantin Olchanski, Bug Report, Inconsistent handling of odb and evet buffer timeouts 
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.

Most checks are done like this:

now = ss_millitime();
if (client->watchdog > 0      <----- check that the watchdog is enabled
    && now > client->last_activity    <---- check for crazy time stamps from the future
    && now - client->last_activity > client->watchdog_timeout)   <--- normal timeout
        remove_client(client);

But in a few places, the extra checks are missing:

now = ss_millitime();
if (now - client->last_activity > client->watchdog_timeout)
        remove_client(client);

Is this an oversight from when additional checks were added?
Should I make all checks read like the first one?

K.O.
    Reply  28 Oct 2008, Stefan Ritt, Bug Report, Inconsistent handling of odb and evet buffer timeouts 
> 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.
> 
> Most checks are done like this:
> 
> now = ss_millitime();
> if (client->watchdog > 0      <----- check that the watchdog is enabled
>     && now > client->last_activity    <---- check for crazy time stamps from the future
>     && now - client->last_activity > client->watchdog_timeout)   <--- normal timeout
>         remove_client(client);
> 
> But in a few places, the extra checks are missing:
> 
> now = ss_millitime();
> if (now - client->last_activity > client->watchdog_timeout)
>         remove_client(client);
> 
> Is this an oversight from when additional checks were added?
> Should I make all checks read like the first one?
> 
> K.O.

This is on purpose. Inside cm_watchdog(), the system check for client->watchdog > 0. If the watchdog 
timeout is zero, the client is not removed. This feature is used if you debug a program. If you come to a 
breakpoint and sit there for a while, you might be declared dead and the application is removed from the 
ODB, meaning that you cannot continue debugging (on the next ODB access the application asserts). This 
can be avoided by setting the watchdog to zero, which is implemented in most applications by supplying 
"-d" on the command line. Now assume you debug a program, so you set the watchdog timeout to zero, but in 
the debugging session you decide to quit. Since the watchdog timeout is zero, you will never be removed 
from the ODB. Therefore, the code inside cm_cleanup() doe NOT check client->watchdog > 0. Therefore, a 
"cleanup" inside odbedit will even remove clients having the timeout set to zero. 

Now there might be more clever ways to accomplish that, but that's how it is implemented right now.
Entry  24 Jul 2023, Nick Hastings, Bug Report, Incompatible data types with mysql odbc interface 
Hello,

I have recently set up a midas-2022-05-c instance and have been trying to configure
it to use the mysql odbc interface. Tables are being created for it but
the logger is issuing errors that some of the column types are incorrect. For example
in the log I see:

14:22:12.689 2023/07/25 [Logger,ERROR] [history_odbc.cxx:1531:hs_define_event,ERROR] Error: History event 'Run transitions': Incompatible data type for tag 'State' type 'UINT32', SQL column 'state' type 'INT UNSIGNED'
14:22:12.689 2023/07/25 [Logger,ERROR] [history_odbc.cxx:1531:hs_define_event,ERROR] Error: History event 'Run transitions': Incompatible data type for tag 'Run number' type 'UINT32', SQL column 'run_number' type 'INT UNSIGNED'

Checking the table in the database I see:

MariaDB [t2kgscND280]> describe run_transitions;
+------------+------------------+------+-----+---------------------+-------------------------------+
| Field      | Type             | Null | Key | Default             | Extra                         |
+------------+------------------+------+-----+---------------------+-------------------------------+
| _t_time    | timestamp        | NO   | MUL | current_timestamp() | on update current_timestamp() |
| _i_time    | int(11)          | NO   | MUL | NULL                |                               |
| state      | int(10) unsigned | YES  |     | NULL                |                               |
| run_number | int(10) unsigned | YES  |     | NULL                |                               |
+------------+------------------+------+-----+---------------------+-------------------------------+
4 rows in set (0.000 sec)

Please note that this is not the only history variable that has this problem. There are multiple variables
for which:

Incompatible data type for tag 'Foo Bar' type 'UINT32', SQL column 'foo_bar' type 'INT UNSIGNED'

Checking history_odbc.cxx, I see:

static const char *sql_type_mysql[] = {
   "xxxINVALIDxxxNULL", // TID_NULL
   "tinyint unsigned",  // TID_UINT8
   "tinyint",           // TID_INT8
   "char",              // TID_CHAR
   "smallint unsigned", // TID_UINT16
   "smallint",          // TID_INT16
   "integer unsigned",  // TID_UINT32
   "integer",           // TID_INT32
   "tinyint",           // TID_BOOL
   "float",             // TID_FLOAT
   "double",            // TID_DOUBLE
   "tinyint unsigned",  // TID_BITFIELD
   "VARCHAR",           // TID_STRING
   "xxxINVALIDxxxARRAY",
   "xxxINVALIDxxxSTRUCT",
   "xxxINVALIDxxxKEY",
   "xxxINVALIDxxxLINK"
};

So it seems that unsigned int should map to UINT32.

The database is:
Server version: 10.5.16-MariaDB MariaDB Server

Please let me know if more information is needed.

Note that the choice of using the odbc interface is because we
plan to import an old database that was created using the odbc interface
with a previous version of midas (yes this is your old friend T2K/ND280).

Regards,

Nick.
    Reply  25 Jul 2023, Nick Hastings, Bug Report, Incompatible data types with mysql odbc interface 
Hello,

wanted add few things:

1. I see the same problem for INT32
2. For now I've worked around these problems with https://bitbucket.org/nickhastings/midas/commits/e4776f7511de0647077c8c80d43c17bbfe2184fd
3. I'm using mariadb-connector-odbc-3.1.12-3.el9.x86_64 (System is AlmaLinux 9)

Regards,

Nick.
Entry  13 Jun 2023, Thomas Senger, Forum, Include subroutine through relative path in sequencer 
Hi, I would like to restructure our sequencer scripts and the paths. Until now many things are not generic at all. I would like to ask if it is possible to include files through a relative path for example something like 
INCLUDE ../chip/global_basic_functions
Maybe I just did not found how to do it.
    Reply  13 Jun 2023, Stefan Ritt, Forum, Include subroutine through relative path in sequencer 
> Hi, I would like to restructure our sequencer scripts and the paths. Until now many things are not generic at all. I would like to ask if it is possible to include files through a relative path for example something like 
> INCLUDE ../chip/global_basic_functions
> Maybe I just did not found how to do it.

It was not there. I implemented it in the last commit.

Stefan
    Reply  13 Jun 2023, Marco Francesconi, Forum, Include subroutine through relative path in sequencer 
> > Hi, I would like to restructure our sequencer scripts and the paths. Until now many things are not generic at all. I would like to ask if it is possible to include files through a relative path for example something like 

> > INCLUDE ../chip/global_basic_functions

> > Maybe I just did not found how to do it.

> 

> It was not there. I implemented it in the last commit.

> 

> Stefan



Hi Stefan,

when I did this job for MEG II we decided not to include relative paths and the ".." folder to avoid an exploit called "XML Entity Injection".

In short is to avoid leaking files outside the sequencer folders like  /etc/password or private SSH keys.

I do not remember in this moment why we pushed for absolute paths instead but let's keep this in mind.



Marco
    Reply  13 Jun 2023, Stefan Ritt, Forum, Include subroutine through relative path in sequencer 
> when I did this job for MEG II we decided not to include relative paths and the ".." folder to avoid an exploit called "XML Entity Injection".
> In short is to avoid leaking files outside the sequencer folders like  /etc/password or private SSH keys.
> I do not remember in this moment why we pushed for absolute paths instead but let's keep this in mind.

I thought about that. But before we had absolute paths in the sequencer INCLUDE statement. So having "../../../etc/passwd" is as bad as the
absolute path "/etc/passwd". So nothing really changed. What we really should prevent is to LOAD files into the sequencer from outside the
sequence subdirectory. And this is prevented by the file loader. Actually we will soon replace the file loaded with a modern JS dialog, and
the code restricts all operations to within the experiment directory and below.

Stefan
Entry  17 Dec 2020, Amy Roberts, Suggestion, Improving variable functionality in Sequencer? 
We're using the sequencer to manage runs, and this typically looks something like:

1. save ODB keys to variables via ODBGET
2. set ODB keys to new values for a "pre-run" process
3. return ODB keys to values created in line 1
4. take data

The problem I'm running into is that the list of ODB keys to save is pretty 
unwieldy.  I'm wondering if there are sequencer features that exist or that I could 
request that might make this easier.

For example, having a way to list ODB keys, save ODB directories, and load ODB 
directories would be much more concise way for me to write my script.

Another option might be to have some version of the ODBSET wildcards for ODBGET.  
Although for this, setting the variable names might be tricky.  

In any case, even being able to ODBGET an array and set that to one variable name 
would be a big improvement.
    Reply  05 Jan 2021, Amy Roberts, Suggestion, Improving variable functionality in Sequencer? 
Hello, just wanted to re-ping on this question now that folks are starting to get back from 
the holidays.
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