Hi,
with the recent fix of the CMakeLists.txt, it seems like another bug surfaced. 
In midas/progs/mlogger.cxx:48/49, the mysql header files are included without a 
prefix. However, mysql.h and mysqld_error.h are in a subdirectory, so for our 
systems, the lines should be
  48 #include <mysql/mysql.h>
  49 #include <mysql/mysqld_error.h>
This is the case with MariaDB 10.5.5 on OpenSuse Leap 15.2, MariaDB 10.5.5 on 
Fedora Workstation 34 and MySQL 5.5.60 on Raspbian 10.

If this problem occurs for other Linux/MySQL versions as well, it should be 
fixed in mlogger.cxx and midas/src/history_schema.cxx.
If this problem only occurs on some distributions or MySQL versions, it needs 
some more differentiation than #ifdef OS_UNIX. 

Also, this somehow seems familiar, wasn't there such a problem in the past?

Dear all,
is there any way to order the labels in the history plot legend? In the old 
system there was the “order” column in the config panel, but I can not find it 
in the new system. Thanks in advance for the support.

Best regards,
Marco Chiappini

Hi,

I am running a simple FE executable that is supposed to define a PRAW DWORD bank.
The issue is that, right after the start of the run, the logger crashes without messages.
Then the FE reports this error, which is rather confusing.
```
12:59:29.140 2021/05/24 [feTestDatastruct,ERROR] [odb.cxx:6986:db_set_data1,ERROR] "/Equipment/Trigger/Variables/PRAW" is of type UINT32, not UINT32
```

I solved this, it was a failed "make clean" before recompiling. Now it works.

Sorry for the noise.

Francesco

> Dear all,
>       I'm trying to use the logging on a mysql DB. Following the instructions on 
> the Wiki, I recompiled MIDAS after installing mysql, and cmake with NEED_MYSQL=1 
> can find it:
> 
> -- MIDAS: Found MySQL version 8.0.23
> 
> Then, I compiled my frontend (cmake with no options + make) and run it, but in the 
> ODB I cannot find the tree for mySQL. I have only:
> 
> Logger/Runlog/ASCII
> 
> while I would expect also:
> 
> Logger/Runlog/SQL
> 
> What could be missing? Maybe should I add something in the CMakeList file or run 
> cmake with some option?
> 
> Thank you,
>       Francesco

a big update to the event buffer code was merged today.

two important bug fixes:

- a logic error in bm_receive_event() (actually bm_fill_read_cache_locked()) 
caused use of uninitialized variable to increment the read pointer and crash 
with error "read pointed points to an invalid event")
- missing bm_unlock() in bm_flush_cache() caused double-locking of event buffer 
caused a hang and a subsequent crash via the watchdog timeout.

several improvements:

- bm_receive_event_vec(std::vector<char>) with automatic memory allocation, one 
does not need to worry about providing a large event buffer to receive event 
data. For local connections MAX_EVENT_SIZE is no longer used, for remote 
connections, a buffer of MAX_EVENT_SIZE is allocated automatically, this is a 
limitation of the MIDAS RPC layer (it does not know how to allocate memory to 
receive arbitrary large data)

(MAX_EVENT_SIZE is now only used in bm_receive_event_rpc()).

- rpc_send_event_sg() - thread safe method to send events to the mserver. it 
takes an array of scatter-gather buffers, so a midas event does not have to be 
in one continious buffer.

- bm_send_event_sg() - same for local connections.

- on top of bm_send_event_sg() we now have bm_send_event_vec(std::vector<char>) 
and bm_send_event_vec(std::vector<vector<char>>). now we can move forward with 
implementing a new "event object" (the TMEvent event object from midasio.h 
already works with these new methods).

- remote connected bm_send_event() & co now always send events to the mserver 
using the event socket. (before, bm_send_event() used RPC_BM_SEND_EVENT and 
suffered from the RPC layer encoding/decoding overhead. mfe.c used 
rpc_send_event() for remote connections)

- bm_send_event(), bm_receive_event() & co now take a timeout value (in 
milliseconds) instead of an async_flag. The old async_flag values BM_WAIT and 
BM_NO_WAIT continue working as expected (wait forever and do not wait at all, 
respectively).

- following improvements are only for remote connections:

- in the case of event buffer congestion (event readers are slow, event buffers 
are close to 100% full), the bm_flush_cache() RPC will no longer timeout due to 
mserver being stuck waiting for free buffer space. (RPC is called with a 1000 
msec timeout, infinite loop waiting for flush is done on the frontend side, the 
RPC timeout will never fire)

- in the case of event buffer congestion, ODB RPC will no longer timeout. 
(previously mserver was stuck waiting for free buffer space and did not process 
any RPCs).

- at the end of run, last few events could be stuck in the event socket. now, 
frontends can flush it using bm_flush_cache(0,BM_WAIT) (use zero for the buffer 
handle). correct run transition should stop the trigger, stop generating new 
events, call bm_flush_cache(0,BM_WAIT), call bm_flush_cache("SYSTEM",BM_WAIT) 
and return success. (TMFE frontend already does this). Note that 
bm_flush_cache(BM_WAIT) can be stuck for very long time waiting for the event 
buffers to empty-out, so run transition RPC timeout is still possible.

K.O.

Dear all,
      I'm trying to use the logging on a mysql DB. Following the instructions on 
the Wiki, I recompiled MIDAS after installing mysql, and cmake with NEED_MYSQL=1 
can find it:

-- MIDAS: Found MySQL version 8.0.23

Then, I compiled my frontend (cmake with no options + make) and run it, but in the 
ODB I cannot find the tree for mySQL. I have only:

Logger/Runlog/ASCII

while I would expect also:

Logger/Runlog/SQL

What could be missing? Maybe should I add something in the CMakeList file or run 
cmake with some option?

Thank you,
      Francesco

> Thanks a lot, this solved my issue!

... or we should turn IPv6 off by default, since not many people use this right now.

> > It looks like mhttpd managed to bind to the IPv4 address (localhost), but not the IPv6 address (::1). If you don't need it, try setting "/Webserver/Enable IPv6" to false.
> 
> We had this issue already several times. This info should be put into the documentation at a prominent location.
> 
> Stefan

Thanks a lot, this solved my issue!

OS: OSX 10.14.6 Mojave
MIDAS: Downloaded from repo on April 2021.

I have a slow control frontend doing the command/readout of a MPOD HV/LV. Since I am reading out the current that are in nA (after updating snmp), I wanted to multiply the number by 1e9.

I noticed the new "Formula" field (introduced in 2019 it seems) instead of the "Factor/Offset" I was used to. None of my entries seems to be accepted (after hitting save, when coming back thee field is empty).

Looking in ODB in "/History/Display/MPOD/HV (Current)/", the field "Formula" is a string of size 32 (even if I have multiple plots in that display). I noticed that the fields "Factor" and "Offset" are still existing and they are arrays with the correct size. However, changing the values does not seem to do anything.

Deleting "Formula" by hand and creating a new field as an array of string (of correct length) seems to do the trick: the formula is displayed in the History display config, and correctly used.

> It looks like mhttpd managed to bind to the IPv4 address (localhost), but not the IPv6 address (::1). If you don't need it, try setting "/Webserver/Enable IPv6" to false.

We had this issue already several times. This info should be put into the documentation at a prominent location.

Stefan

> midas_hatfe_1  | Mongoose web server listening on http address "localhost:8080", passwords OFF, hostlist OFF
> midas_hatfe_1  | [mhttpd,ERROR] [mhttpd.cxx:19160:mongoose_listen,ERROR] Cannot mg_bind address "[::1]:8080"

It looks like mhttpd managed to bind to the IPv4 address (localhost), but not the IPv6 address (::1). If you don't need it, try setting "/Webserver/Enable IPv6" to false.

Hi,

Using midas version 12-2020,  I am trying to run mhttpd from within a docker container using docker-compose.
Starting from an empty ODB, I simply run `mhttpd` and this is the output I have:
midas_hatfe_1  | <Warning> Starting mhttpd...
midas_hatfe_1  | [mhttpd,INFO] ODB subtree /Runinfo corrected successfully
midas_hatfe_1  | MVOdb::SetMidasStatus: Error: MIDAS db_find_key() at ODB path "/WebServer/Host list" returned status 312
midas_hatfe_1  | Mongoose web server will not use password protection
midas_hatfe_1  | Mongoose web server will not use the hostlist, connections from anywhere will be accepted
midas_hatfe_1  | Mongoose web server listening on http address "localhost:8080", passwords OFF, hostlist OFF
midas_hatfe_1  | [mhttpd,ERROR] [mhttpd.cxx:19160:mongoose_listen,ERROR] Cannot mg_bind address "[::1]:8080"

According to the documentation, the WebServer tree should be created automatically when starting the mhttpd; but it seems not as it doesn't find the entry "/WebServer/Host list".
If I create it by end (using "create STRING /WebServer/Host list"), I still get the error message that mhttpd didn't bind properly to the local port 8080.
I am not sure what it wrong, as mhttpd is working perfectly well in this exact container for midas 03-2020.

Any idea what difference makes it not possible anymore to run into these container?

Thanks very much for your help.
Cheers
Mathieu

Thanks for reporting that bug, I fixed it in the last commit.

Stefan

It seems that a modbselect triggers a "change" in an ODB which has a hot link. This happens onload (or whenever the custom page is reloaded) and otherwise it behaves as expected, i.e. no change unless the modbselect is actually changed. Is this the intended behaviour? can this be modified?

For those unfamiliar, odbxx is the interface that looks like a C++ map, but automatically syncs with the ODB - https://midas.triumf.ca/MidasWiki/index.php/Odbxx.

I've added a new feature that is similar to the existing odb::connect() function, but works like the old db_check_record(). The new odb::connect_and_fix_structure() function:
- keeps the existing value of any keys that are in both the ODB and your code
- creates any keys that are in your code but not yet in the ODB
- deletes any keys that are in the ODB but not your code
- updates the order of keys in the ODB to match your code

This will hopefully make it easier to automate ODB structure changes when you add/remove keys from a frontend.

The new feature is currently in the develop branch, and should be included in the next release.

Thanks for reporting and pointing to the right location.

I fixed and committed it.

Best,
Stefan

We had the same issue here, which comes from mhttpd.js line 2395 on the current git version. This seems to happen mostly when there is an alarm triggered or when there is an error message.

Anyway, the easiest solution for us was to define m at the beginning of mhttpd_message function 

let m;

and replace line 2395 with

if (m !== undefined) {


> > I see this mhttpd error starting MSL-script: 
> > Uncaught (in promise) ReferenceError: m is not defined
> > at mhttpd_message (VM2848 mhttpd.js:2304)
> > at VM2848 mhttpd.js:2122
> 
> your line numbers do not line up with my copy of mhttpd.js. what version of midas 
> do you run?
> 
> please give me the output of odbedit "ver" command (GIT revision, looks like this: 
> IT revision:       Wed Feb 3 11:47:02 2021 -0800 - midas-2020-08-a-84-g78d18b1c on 
> branch feature/midas-2020-12).
> 
> same info is in the midas "help" page (GIT revision).
> 
> to decipher the git revision string:
> 
> midas-2020-08-a-84-g78d18b1c means:
> is commit 78d18b1c
> which is 84 commits after git tag midas-2020-08-a
> 
> "on branch feature/midas-2020-12" confirms that I have the midas-2020-12 pre-
> release version without having to do all the decoding above.
> 
> if you also have "-dirty" it means you changed something in the source code 
>  and warranty is voided. (just joking! we can debug even modified midas source 
> code)
> 
> K.O.

> > The new history as well as the clock in the web page header show the local time 
> > of the user's computer running the browser.
> > Would it be possible to make it either always use the time zone of the Midas 
> > server, or make it selectable from the config page?
> > It's not ideal trying to relate error messages from the midas.log to history 
> > plots if the time stamps don't match.
> 
> I implemented a new row in the config page to select the time zone. 
> 
> "Local": Time zone where the browser runs
> "Server": Time zone where the midas server runs (you have to update mhttpd for that)
> "UTC+X": Any other time zone
> 
> The setting affects both the status header and the history display.
> 
> I spent quite some time with "named" time zones like "PST" "EST" "CEST", but the 
> support for that is not that great in JavaScript, so I decided to go with simple 
> UTC+X. Hope that's ok.
> 
> Please give it a try and let me know if it's working for you.
> 
> Best,
> Stefan

Hi Stefan,

This is great, the UTC+x is perfect, thank you.
PAA

I found a way to embed modbvalue into a SVG:

<text x="100" y="100" font-size="30rem">
Run=<tspan class="modbvalue" data-odb-path="/Runinfo/Run number"></tspan>
</text>

This seems to behave better that the suggestion below.

> You can't really embed it, but you can overlay it. You tag the SVG with a 
> "relative" position and then move the modbvalue with an "absolute" position over 
> it:
> 
> <svg style="position:relative" width="400" height="100">
>   <rect width="300" height="100" style="fill:rgb(255,0,0);stroke-width:3;stroke:rgb(0,0,0)" />
>   <div class="modbvalue" style="position:absolute;top:50px;left:50px" data-odb-path="/Runinfo/Run number"></div>
> </svg>

> Version: release/midas-2020-12
> 
> In the new history display, the checkbox "Change all time axes together" works 
> well with the mouse-based zoom, but does not apply to the +- buttons.

Fixed in current commit.

Stefan