> I'm not sure if this is the right forum for this query

this might be the right place, depending.

> I'm having a little bit of trouble with the setup of a Midas system ...
> inherited after the previous guy ...

a rather major problem, but a typical situation.

> There was a point at which it was working.

this is very good. if it worked before, there is good chance it will work again.

> And then there was an unrelated issue in the electrical system which, as a side effect,
> meant that the building lost power for a time, and the entire system had to be rebooted.
> No problem, I thought. I'll just reset and restart all of the software...
> ...and I can't seem to get it to work.

this happens often enough. several things are likely to happen:
- unexpected software updates, i.e. new linux kernel was installed but inactive, waiting for a reboot
- hardware failures, i.e. we usually see blown up power supplies. check that all VME crate voltages are okey. (ask me how).
- firmware corruption, i.e. we have seen VME modules lose their firmware after power outage, had to be reloaded by jtag

> I keep getting the error message "mvme_read_value: Could not perform read!: Bad address".

this is a generic error, it does not mean that software suddenly is trying to read from wrong address.

> I imagine that there is something that needs to be set, twiddled, tweaked, or turned on in the driver. The output of 'lsmod | grep vme' is:
> vmedriver             117742  0

this is not the vme driver we use at TRIUMF, so I am not familiar with it's errors. we use the vme_tsi148 driver and the vme_universe driver. (ask me about them).

> so presumably the driver is at least *present*, even if I have no idea how to twiddle anything on it.

could be the wrong version of the driver or the wrong version of the linux kernel. worth checking log files
to see if kernel and driver version numbers are the same.

> Could anyone perhaps suggest a way forward?

Yes. You will have to tell me much more about your system. You can do this publicly here or privately by email to olchansk@triumf.ca

To start, I need to know your VME setup, what is the crate, what is the VME processor, what OS you run, what VME driver you use, what VME modules you have installed.

K.O.

midas bitbucket repository had a spam attack, about 40 spam messages were posted 
into the issues. I was able to delete them manually. No idea how they got past 
bitbucket spam filters and if they are spam or an attack against automated issue 
tracker tools or an attack against the repo owner (who is vulnerable as they rush 
in to deal with the spam). if this happens again, "anonymous issues" may have to 
be disabled, bitbucket login required. K.O.

Hi

I'm not sure if this is the right forum for this query (if it is not, I would truly appreciate it if someone could point me at the right forum). I'm having a little bit of trouble with the setup of a Midas system.

Now, this is a system that I inherited after the previous guy who was looking after it went to other employment. There was a point at which it was working. And then there was an unrelated issue in the electrical system which, as a side effect, meant that the building lost power for a time, and the entire system had to be rebooted.

No problem, I thought. I'll just reset and restart all of the software...

...and I can't seem to get it to work. I keep getting the error message "mvme_read_value: Could not perform read!: Bad address". So far as I can tell, this seems to be related to the idea that the base address being used to read from the boards is incorrect. The base addresses are hardcoded in the software (not autogenerated) and, aside from the power going down and up again, the hardware hasn't been touched since the system was working.

I imagine that there is something that needs to be set, twiddled, tweaked, or turned on in the driver. The output of 'lsmod | grep vme' is:

vmedriver             117742  0

so presumably the driver is at least *present*, even if I have no idea how to twiddle anything on it.

Could anyone perhaps suggest a way forward? Is there some way to gather the information that I need, perhaps, or some way to twiddle anything twiddle-able on the driver?

Casey

> > Dear all,
> > 
> > we are experiencing a connection problem to the MySQL server that we use to log informations. Is there an 
> > option to retry multiple times the I/O on the MySQL?
> > 
> > The error we are experiencing is the following (hiding the IP address):
> > 
> > [Logger,ERROR] [mlogger.cxx:2455:write_runlog_sql,ERROR] Failed to connect to database: Error: Can't 
> > connect to MySQL server on 'xxx.xxx.xxx.xxx:6033' (110)
> > 
> > Then the logger stops, and must be restarted. This eventually happens only during the BOR or the EOR.
> 
> What would you propose? If the connection does not work, most likely the server is down or busy. If we retry, 
> the connection still might not work. If we retry many times, people will complain that the run start or stop 
> takes very long. If we then just continue (without stopping the logger), the MySQL database will miss important 
> information and the runs probably cannot be analyzed later. So I believe it's better to really stop the logger 
> so that people get aware that there is a problem and fix the source, rather than curing the symptoms.
> 
> In the MEG experiment at PSI we run the logger with a MySQL database and we never see any connection issue, 
> except when the MySQL server gets in maintenance (once a year), but usually we don't take data then. Since we 
> use the same logger code, it cannot be a problem there. So I would try to fix the problem on the MySQL side.
> 
> Best,
> Stefan


Dear Stefan,

a possible solution could be to define the number of times to retry as a parameter that is 0 by default, as well as a wait time between two subsequent tries. This 
would leave the decision on how to handle a possible failed connection to the user. In our case, for example, we would prefer to not stop the acquisition in case 
of a failed connection to the external SQL. In addition, we have other software that, with a retry procedure, doesn’t fail: with 1 re-try and a sleep time of 0.5 s 
we already recover 100% of the faults.

Anyway, we implemented a local database, which is a mirror of the external one, and the problems disappeared.

Thanks,
Stefano.

Hi Konstantin,
thanks for this update |

My main interest for PostgreSQL is usage of TimescaleDB
(https://github.com/timescale/timescaledb) a PostgreSQL extension that
makes possible usage of downsampling functions on time-series...

here at INFN-Napoli we have a large history dataset that we manage
with MIDAS history and MySQL tables. We have a lot of issues 
(wait time, browser hangs, crashes) when we use MIDAS history plot 
pages on large time period because the Javascript web page try to 
download million of records in order to display them on a plot of 
(max) 2000 pixel width...

with native downsampling we can reduce a large dataset keeping the
"shape" of the curve using only the points needed by the plot area;

in TimescaleDB there is "lttb" ( Largest Triangle Three Bucket) a very 
nice and impressive downsampling function that preserve very well the
shape of the series.

If you are interested to see a lttb at work on some data you can open this page:
   https://www.base.is/flot

In next days I will work to add TimescaleDB backend to MIDAS history (it will be
similar to PostgreSQL backend) and we can discuss on how to add these 
downsampling features to history plot web pages, I already developed some
solutions and I will be happy to share them with MIDAS community;

Cheers,
Gennaro

> > some minutes ago I published a PR for PostgreSQL support I developed
> > at INFN-Napoli for Darkside experiment...
> > 
> > I don't know if you receive a notification about this PR and in doubt
> > I wrote this message...
> 
> Hi, Gennaro, thank you for the very useful contribution. I saw the previous version 
> of your pull request and everything looked quite good. But that pull request was 
> for an older version of midas and it would not have applied cleanly to the current 
> version. I will take a look at your updated pull request. In theory it should only 
> add the Postgres class and modify a few other places in history_schema.cxx and have 
> no changes to anything else. (if you need those changes, it should be a separate 
> pull request).
> 
> Also I am curious what benefits and drawbacks of Postgres vs mysql/mariadb you have 
> observed for storing and using midas history data.
> 
> K.O.

Hi 


> > some minutes ago I published a PR for PostgreSQL support I developed
> > at INFN-Napoli for Darkside experiment...
> > 
> > I don't know if you receive a notification about this PR and in doubt
> > I wrote this message...
> 
> Hi, Gennaro, thank you for the very useful contribution. I saw the previous version 
> of your pull request and everything looked quite good. But that pull request was 
> for an older version of midas and it would not have applied cleanly to the current 
> version. I will take a look at your updated pull request. In theory it should only 
> add the Postgres class and modify a few other places in history_schema.cxx and have 
> no changes to anything else. (if you need those changes, it should be a separate 
> pull request).
> 
> Also I am curious what benefits and drawbacks of Postgres vs mysql/mariadb you have 
> observed for storing and using midas history data.
> 
> K.O.

> some minutes ago I published a PR for PostgreSQL support I developed
> at INFN-Napoli for Darkside experiment...
> 
> I don't know if you receive a notification about this PR and in doubt
> I wrote this message...

Hi, Gennaro, thank you for the very useful contribution. I saw the previous version 
of your pull request and everything looked quite good. But that pull request was 
for an older version of midas and it would not have applied cleanly to the current 
version. I will take a look at your updated pull request. In theory it should only 
add the Postgres class and modify a few other places in history_schema.cxx and have 
no changes to anything else. (if you need those changes, it should be a separate 
pull request).

Also I am curious what benefits and drawbacks of Postgres vs mysql/mariadb you have 
observed for storing and using midas history data.

K.O.

Hi,

some minutes ago I published a PR for PostgreSQL support I developed
at INFN-Napoli for Darkside experiment...

I don't know if you receive a notification about this PR and in doubt
I wrote this message...

Thanks in advance,
Gennaro

> Dear all,
> 
> we are experiencing a connection problem to the MySQL server that we use to log informations. Is there an 
> option to retry multiple times the I/O on the MySQL?
> 
> The error we are experiencing is the following (hiding the IP address):
> 
> [Logger,ERROR] [mlogger.cxx:2455:write_runlog_sql,ERROR] Failed to connect to database: Error: Can't 
> connect to MySQL server on 'xxx.xxx.xxx.xxx:6033' (110)
> 
> Then the logger stops, and must be restarted. This eventually happens only during the BOR or the EOR.

What would you propose? If the connection does not work, most likely the server is down or busy. If we retry, 
the connection still might not work. If we retry many times, people will complain that the run start or stop 
takes very long. If we then just continue (without stopping the logger), the MySQL database will miss important 
information and the runs probably cannot be analyzed later. So I believe it's better to really stop the logger 
so that people get aware that there is a problem and fix the source, rather than curing the symptoms.

In the MEG experiment at PSI we run the logger with a MySQL database and we never see any connection issue, 
except when the MySQL server gets in maintenance (once a year), but usually we don't take data then. Since we 
use the same logger code, it cannot be a problem there. So I would try to fix the problem on the MySQL side.

Best,
Stefan

Dear all,

we are experiencing a connection problem to the MySQL server that we use to log informations. Is there an 
option to retry multiple times the I/O on the MySQL?

The error we are experiencing is the following (hiding the IP address):

[Logger,ERROR] [mlogger.cxx:2455:write_runlog_sql,ERROR] Failed to connect to database: Error: Can't 
connect to MySQL server on 'xxx.xxx.xxx.xxx:6033' (110)

Then the logger stops, and must be restarted. This eventually happens only during the BOR or the EOR.

Best,
Stefano.

> I agree with you, option 2 is better and works well. 
> The only problem is that if you are showing multiple histograms in the same window the keyDown even will affect all of the histories in the window. 
> This may be the intended behaviour, but I think that if we can find a way to have the event affecting only the intended history (focused element for example) it would be better.

The history panels are simple pictures from the perspective of the browser and have no concept of a focus. This would have to be tweaked somehow. If you want to reset a single history, 
just click on its reset button (circle arrow at the right top).

Stefan

I agree with you, option 2 is better and works well. 
The only problem is that if you are showing multiple histograms in the same window the keyDown even will affect all of the histories in the window. 
This may be the intended behaviour, but I think that if we can find a way to have the event affecting only the intended history (focused element for example) it would be better.

Zaher 

> > The histories capture key events from 'r' 'u' 'y' and 'Escape' for various functions like rescaling etc. However, this also means that if we include an editable modbvalue and a history in the same custom page then changing the modbvalue to something that includes 'ruy' is not possible.
> > 
> > In mhistory.js we have
> > 
> > // Keyboard event handler (has to be on the window!)
> > window.addEventListener("keydown", this.keyDown.bind(this));
> > 
> > I am not sure why it "has to be on the window". For now, I am bypassing this issue by changing the event listener to "keyup" but maybe there is a more elegant solution for this. Adding the event listener to the div element that includes the history does not seem to work.
> 
> I could reproduce the problem. I see two options there:
> 
> 1) We replace 'r' with 'Ctrl-r' etc. 
> 
> 2) We change the history JS code not to process keyboard inputs if we are currently editing a value.
> 
> I added 2) to give it a try. It works fine for me. The additional code is
> 
> MhistoryGraph.prototype.keyDown = function (e) {
>    // don't consume events if we are editing a value
>    if (e.target.tagName === "INPUT")
>       return;
>    ...
> }
> 
> 
> Feedback is welcome.
> 
> Stefan

> The histories capture key events from 'r' 'u' 'y' and 'Escape' for various functions like rescaling etc. However, this also means that if we include an editable modbvalue and a history in the same custom page then changing the modbvalue to something that includes 'ruy' is not possible.
> 
> In mhistory.js we have
> 
> // Keyboard event handler (has to be on the window!)
> window.addEventListener("keydown", this.keyDown.bind(this));
> 
> I am not sure why it "has to be on the window". For now, I am bypassing this issue by changing the event listener to "keyup" but maybe there is a more elegant solution for this. Adding the event listener to the div element that includes the history does not seem to work.

I could reproduce the problem. I see two options there:

1) We replace 'r' with 'Ctrl-r' etc. 

2) We change the history JS code not to process keyboard inputs if we are currently editing a value.

I added 2) to give it a try. It works fine for me. The additional code is

MhistoryGraph.prototype.keyDown = function (e) {
   // don't consume events if we are editing a value
   if (e.target.tagName === "INPUT")
      return;
   ...
}


Feedback is welcome.

Stefan

> Is it possible to impose requirements on certain output variables in an interlock-like fashion? For example: "As long as the temperature exceeds a certain threshold, a light switched by a relay cannot be turned on."
> 
> A workaround would be to set an alarm on that variable and call a script which turns the light back off, but that might not be ideal in certain scenarios. For safety-critical situations, a PLC would be preferred, but I am missing an option between those two.

No, interlocks of that kind are not implemented in midas. And that is for a good reason. Interlocks are critical, so one must be sure 100% that they are working. This cannot be done with complex software such as midas. You have to use dedicated hardware for that. 
Most people use a PLC controller which is made for that. Midas is then only used to read and display the status of the interlock controller.

Stefan

Is it possible to impose requirements on certain output variables in an interlock-like fashion? For example: "As long as the temperature exceeds a certain threshold, a light switched by a relay cannot be turned on."

A workaround would be to set an alarm on that variable and call a script which turns the light back off, but that might not be ideal in certain scenarios. For safety-critical situations, a PLC would be preferred, but I am missing an option between those two.

These debug statements were added by K.O. on June 24, 2021. He should remove it.

https://bitbucket.org/tmidas/midas/commits/21f7ba89a745cfb0b9d38c66b4297e1aa843cffd

Best,
Stefan

Hi everyone,

It has been a long time since my last message. While porting Midas front-end 
programs developed for the T2K experiment in 2008 to a modern version of Midas, 
I noticed that some debug printf remain in mhttpd.cxx.

A number of debug messages are printed on stdout each time a graph is displayed 
in the OldHistory window (which is the style of history plots that will continue 
to be used in the upgraded T2K experiment for some technical reasons).

Here is an example of such debug messages:
Load from ODB History/Display/HA_EP_0/V33: hist plot: 8 variables
timescale: 1h, minimum: 0.000000, maximum: 0.000000, zero_ylow: 0, log_axis: 0, 
show_run_markers: 1, show_values: 1, show_fill: 0, show_factor 0, enable_factor: 
1
var[0] event [HA_TPC_SC][E0M00FEM_V33] formula [], colour [#00AAFF] label 
[Mod_0] show_raw_value 0 factor 1.000000 offset 0.000000 voffset 0.000000 order 
10
var[1] event [HA_TPC_SC][E0M01FEM_V33] formula [], colour [#FF9000] label 
[Mod_1] show_raw_value 0 factor 1.000000 offset 0.000000 voffset 0.000000 order 
20
var[2] event [HA_TPC_SC][E0M02FEM_V33] formula [], colour [#FF00A0] label 
[Mod_2] show_raw_value 0 factor 1.000000 offset 0.000000 voffset 0.000000 order 
30
var[3] event [HA_TPC_SC][E0M03FEM_V33] formula [], colour [#00C030] label 
[Mod_3] show_raw_value 0 factor 1.000000 offset 0.000000 voffset 0.000000 order 
40
var[4] event [HA_TPC_SC][E0M04FEM_V33] formula [], colour [#A0C0D0] label 
[Mod_4] show_raw_value 0 factor 1.000000 offset 0.000000 voffset 0.000000 order 
50
var[5] event [HA_TPC_SC][E0M05FEM_V33] formula [], colour [#D0A060] label 
[Mod_5] show_raw_value 0 factor 1.000000 offset 0.000000 voffset 0.000000 order 
60
var[6] event [HA_TPC_SC][E0M06FEM_V33] formula [], colour [#C04010] label 
[Mod_6] show_raw_value 0 factor 1.000000 offset 0.000000 voffset 0.000000 order 
70
var[7] event [HA_TPC_SC][E0M07FEM_V33] formula [], colour [#807060] label 
[Mod_7] show_raw_value 0 factor 1.000000 offset 0.000000 voffset 0.000000 order 
80
read_history: nvars 10, hs_read() status 1
read_history: 0: event [HA_TPC_SC], var [E0M00FEM_V33], index 0, odb index 0, 
status 1, num_entries 475
read_history: 1: event [HA_TPC_SC], var [E0M01FEM_V33], index 0, odb index 1, 
status 1, num_entries 475
read_history: 2: event [HA_TPC_SC], var [E0M02FEM_V33], index 0, odb index 2, 
status 1, num_entries 475
read_history: 3: event [HA_TPC_SC], var [E0M03FEM_V33], index 0, odb index 3, 
status 1, num_entries 475
read_history: 4: event [HA_TPC_SC], var [E0M04FEM_V33], index 0, odb index 4, 
status 1, num_entries 475
read_history: 5: event [HA_TPC_SC], var [E0M05FEM_V33], index 0, odb index 5, 
status 1, num_entries 475
read_history: 6: event [HA_TPC_SC], var [E0M06FEM_V33], index 0, odb index 6, 
status 1, num_entries 475
read_history: 7: event [HA_TPC_SC], var [E0M07FEM_V33], index 0, odb index 7, 
status 1, num_entries 475
read_history: 8: event [Run transitions], var [State], index 0, odb index -1, 
status 1, num_entries 0
read_history: 9: event [Run transitions], var [Run number], index 0, odb index 
-2, status 1, num_entries 0


Looking at the source code of mhttpd, these messages originate from:

[mhttpd.cxx line 10279] printf("Load from ODB %s: ", path.c_str());
[mhttpd.cxx line 10280] PrintHistPlot(*hp);
...
[mhttpd.cxx line  8336] int read_history(...
...
[mhttpd.cxx line  8343] int debug = 1;
...

Although seeing many debug messages in the mhttpd does not hurt, these can hide 
important error messages. I would rather suggest to turn off these debug 
messages by commenting out the relevant lines of code and setting the debug 
variable to 0 in read_history().

That is a minor detail and it is always a pleasure to use Midas.

Best regards,
Denis.
 

> > serious (but rare) bug was fixed in the history reader.
> previous fix was incomplete. please update to git commit
> https://bitbucket.org/tmidas/midas/commits/b343c3c98e4e6fd00a00cf686c74c7ccc6da0c63

a race condition between reading history file in mhttpd and writing history file in 
mlogger was accidentally introduced. mhttpd would file spurious errors about "timestamp 
is after last timestamp".

fixed, please update to git commit
https://bitbucket.org/tmidas/midas/commits/7a9f6e0c58ffddcacb9ee19934ce3e2033a805ef

fix race condition in history file reader - a race condition was added accidentally - 
first the reader remembers the history file size and the time of the last entry, then it 
goes to read the file and bombs if at the same time mlogger added more entries - their 
time is after the remembered time of last entry and error "timestamp is after last 
timestamp" is triggered.

K.O.

> > midas currently does not compile on linux
> > fix is to give open in midas/examples/lowlevel/split.cxx a default mode, e.g. 006600

I got more warnings from split.cxx, looked at the code and see so many problems that it is easier
to delete it than it is to fix it.

Check for end of file is done incorrectly (check for read() return 0, -1 or short read),
memory overrun if given file name is longer than 80 bytes, no check for valid event length
read from the file, and so on and so on.

A better example for reading and writing midas files is in midasio/test_midasio.cxx. Proper c++ coding, and can read compressed files.

K.O.

> midas currently does not compile on linux
> 
> /usr/include/x86_64-linux-gnu/bits/fcntl2.h:50:24: error: call to ‘__open_missing_mode’ declared with attribute error: open with O_CREAT or O_TMPFILE in second argument needs 3 arguments
>    50 |    __open_missing_mode ();
> 
> giving the mode is mandatory: https://man7.org/linux/man-pages/man2/open.2.html
> 
> fix is to give open in midas/examples/lowlevel/split.cxx a default mode, e.g. 006600

Thanks. Fixed.

Stefan