Note The latest up-to-date instructions can be found in the wiki.

Central Historic DQM application for CMS detector

A tool to display trends of CMS DQM quantities over long periods of time.
The web application is available here: https://cms-hdqm.web.cern.ch
The code is running on a vocms0231 machine.

Usage instructions

How to run on LXPLUS

Warning Probably deprecated.

The following instruction are completely copy-pastable. This will start a complete HDQM stack on your local (lxplus) environment. This is perfect for testing new plots before adding them. Instructions are are made for bash shell.

# Enter bash
bash
# You have to change the username. From this point, all instruction can be copy pasted without modifications.
ssh -L 8000:localhost:8000 -L 8080:localhost:5000 <YOUR_USER_NAME>@lxplus7.cern.ch
/bin/bash
mkdir -p /tmp/$USER/hdqm
cd /tmp/$USER/hdqm/

git clone https://github.com/cms-dqm/CentralHDQM
cd CentralHDQM/

cd backend/
# Need to add client secret backend/.env file - ask DQM conveners to provide it.
cp .env_sample .env && nano .env

# This will give us cern-get-sso-cookie -u https://cmsoms.cern.ch/agg/api/v1/runs -o backend/api/etc/oms_sso_cookie.txta CMSSW environment
source cmsenv

# Add python dependencies
python -m venv venv
source venv/bin/activate
python -m pip install -r requirements.txt 


# Extract few DQM histograms. Using only one process because we are on SQLite
./hdqmextract.py -c cfg/PixelPhase1/trendPlotsPixelPhase1_tracks.ini -r 324997 324998 324999 325000 325001 325022 325057 325097 325098 325099 -j 1

# Calculate HDQM values from DQM histograms stored in the DB
./calculate.py -c cfg/PixelPhase1/trendPlotsPixelPhase1_tracks.ini -r 324997 324998 324999 325000 325001 325022 325057 325097 325098 325099 -j 1

# Get the OMS and RR data about the runs
./oms_extractor.py
./rr_extractor.py

cd ../api/
# Run the API
./run.sh &>/dev/null &

cd ../../frontend/

# Run the static file server
python3 server.py &>/dev/null &

# Run this to find pids of running servers to kill them:
# ps awwx | grep python

That's it! Now visit http://localhost:8000/ on your browser.

Main HDQM commands explained

Main HDQM commands are the following:

1. dqm_extractor.py

dqm_extractor.py

This tool is responsible for extracting DQM monitor elements from ROOT files and storing them as binary data in the database. This is separated from HDQM value calculation to ensure that values can be recalculated quickly, without relying on a file system every time.

Argument	Long name	Default value	Description
-r	runs	None	A list of runs. Only MEs containing info of these runs will be extracted and saved. By default, MEs from all runs available in the given DQM files will be extracted.
-c	config	cfg/*/*.ini	A list of .ini configuration files to be used. A pattern of a config file location is this: cfg/<SUBSYSTEM_NAME>/<ARBITRARY_NAME>.ini. This pattern must be followed without any additional folders in between. If a subsystem folder is missing, it can be created.
-f	files	EOS dir	A list of DQM files to be used. This is very useful if you want to do HDQM on your custom set of DQM files. Files still need to follow DQM file naming conventions (must contain a run and a dataset name). Also this can be used to run HDQM on a subset of all DQM ROOT files available in EOS.
-j	nprocs	50	Integer value indicating how many processes to use. When running locally (on SQLite) this has to be 1 because SQLite doesn't support multiple connections writing to the DB.

Default EOS directory for -f argument is this: /eos/cms/store/group/comm_dqm/DQMGUI_data/*/*/*/DQM*.root

Summary

To summarize, by default HDQM will be done on all data available in EOS and all configuration files available in cfg/. The parameters to HDQM tools can be helpful to limit this scope and only extract the required subset of the data or your own data altogether.

How to add new plots

In order to add new plots to HDQM, you have to provide two layers of configuration:

1. backend configuration
2. frontend configuration

Configuration is all in code and in order to add new plots you have to make a pull request against this repo: https://github.com/cms-DQM/CentralHDQM

Backend configuration

Backend is configured with .ini files that describe what monitor elements should be taken from the DQM .root files and how the value from the should be extracted for plotting.
These files are placed here, in a corresponding subsystem directory: backend/extractor/cfg/<subsystem>. This directory structure has to be preserved in order for the tool to work. If subsystem doesn't exist, a folder for it can be created.

Let's take a look at an example:

[plot:Ntracks_Pixel]
metric = basic.BinCount(2)
relativePath = PixelPhase1/Tracks/ntracks
plotTitle = Pixel number of tracks
yTitle = Number of Tracks in Pixel

That's all it takes to tell HDQM how to plot a DQM quantity over time. Let's break this down line by line.

• The first line describes an ID of a plot that is unique per subsystem. This ID will be used to refer to this plot later on. This field is required.
• metric property tells the tool what function needs to be called to reduce a DQM histogram to a single value that will be plotted. Think of this as of a constructor call of a Python class. Classes that can be used are defined here: backend/extractor/metrics/. If necessary, new python classes could be added. New classes have to provide a constructor with as many arguments as it's required to be referred to from the configuration and a calculate(self, histo) method that will be called by the backend. This function has to return a tuple of two values (value, error). For more details, refer to Adding new metric section bellow. This field is required.
• relativePath is a path of a monitor element in a legacy DQM root file that a metric should be applied to. In case a path of a monitor element changed, you can provide multiple, space separated paths here. ME that is found the first will be used. This field is required.
• plotTitle is a title of a plot that will be displayed in a web application. This value can contain spaces as it only has to be human readable. If this field is not provided, yTitle will be used instead. This field is not required.
• yTitle is a title of y axis. It is usually used to display the units used in a plot. This field is required.

Those were the main properties, however there are other less common ones:

histo1Path = PixelPhase1/Phase1_MechanicalView/PXBarrel/num_clusters_PXLayer_2
histo2Path = PixelPhase1/Phase1_MechanicalView/PXBarrel/size_PXLayer_2
threshold = 50

• Sometimes, a value of a point in a trend depends on more than one DQM histogram. In such cases histo1Path and histo2Path could be used to define the paths of the other histograms. These fields are not required.
• threshold was used previously to define a minimum number of entries for a histogram to be taken into a trend. Now, this is no longer used, however this value can be wired in your custom Python extraction class. This field is not required.

Frontend configuration

In a frontend configuration you can define what is called display groups. Display groups define a list of related plots that will be displayed together in a web application, as an overlay.
The configuration is located here: frontend/js/displayConfig.js. All fields here are required!

Let's take a look at an example:

{
  name: "an_id_of_a_display_group",
  plot_title: "Nice, readable title of a group",
  y_title: "Units of all series in a group",
  subsystem: "<Subsystem>",
  correlation: false,
  series: ["plot1_ID", "plot2_ID"],
}

Let's break this down line by line.

• name is an ID of a display group. It has to be unique within all display groups and regular plots within a subsystem.
• plot_title is a title of a grouped plot that will be displayed in a web application.
• y_title is a title of y axis of a grouped plot. It is usually used to display the units used in a plot.
• subsystem is the name of the subsystem. It has to match exactly the name of the folder where backend configuration files came from (backend/extractor/cfg/<subsystem>).
• correlation is a boolean value defining if the plot should be displayed in a correlation mode. This can be true only when there are exactly 2 series in a display group.
• series is an array if plot ID from backend configuration that will appear in a display group.

Adding new metrics

In section we will look at how to add new metrics to the HDQM.

Create a new python file inside metrics directory:

vim backend/extractor/metrics/sampleMetrics.py

Import BasicMetric and define your new class:

from basic import BaseMetric

class Mean(BaseMetric):
  def calculate(self, histo):
    return (histo.GetMean(), histo.GetMeanError())

histo is a full ROOT histogram, which, luckily, already provides getting its mean, so our implementation is very simple. Keep in mind that you always have to return a tuple of 2 numbers: value and error!

Also, all metrics have to inherit BasicMetric and implement calculate(self, histo) method

Now, add the new metric to the calculation script:

vim backend/extractor/calculate.py

Import it:

from metrics import sampleMetrics

And add the new metric to the (already defined) METRICS_MAP:

METRICS_MAP = {'fits': fits, 'basic': basic, 'L1T_metrics': L1T_metrics, 'muon_metrics': muon_metrics, 'sampleMetrics': sampleMetrics}

Now, your newly added metric can be used in the .ini file like this:

metric = sampleMetrics.Mean()

In this definition we are essentially calling a constructor of sampleMetrics.Mean. If you need to pass parameters to the metric, you can define a constructor and pass parameters from the configuration files. For example:

from basic import BaseMetric

class BinCount(BaseMetric):
  def __init__(self,  binNr):
    self.__binNr = binNr
  def calculate(self, histo):    
    return (histo.GetBinContent(self.__binNr), 0)

This will be a trend of counts of first bin:

metric = sampleMetrics.BinCount(1)

Web application usage

In a web application, user has to select the data first by selecting a subsystem, primary dataset and a processing string at a very top of the page and all plots present in selected data will be displayed.

Runs can be filtered in one of the following ways:

• Latest N runs
• Run range
• Comma separated list of runs
• Golden JSON file

By clicking Options button, a display mode of the plots can be chosen. Available display modes are:

• Scatter plot
• Bin width proportional to run duration
• Bin width proportional to integrated luminosity
• Datetime plot based on start and end times of runs
• Correlation plot

By clicking Show / Change ranges button a full screen mode of a plot will be entered. In a full screen mode you can do one of the following things:

• Change the X and Y ranges of a plot
• Click on runs (data points) and reveal more information about them in the right hand side panel
• See the DQM histogram(s) that was used to extract the value of a trend in the right hand side panel
• Look at a selected run in DQM GUI, OMS and Run Registry
• Add or remove series from the plot dynamically by clicking Add series to this plot

API documentation

This very API is powering the web application. No other, hidden API services are used. The web page is all static - no server rendering.

All endpoints should be used by making an HTTP GET request and providing the arguments in the url.

Endpoints

• /api/data
• /api/selection
• /api/plot_selection
• /api/runs
• /api/expand_url

Let's talk about each of them one by one.

/api/data

This is the main endpoint used to retrieve historic DQM data.

Possible arguments:

Param	Data type	Required/Optional	Description
subsystem	string	required	Name of the subsystem. Possible values come from /api/selection endpoint.
pd	string	required	Name of the primary dataset. Possible values come from /api/selection endpoint.
processing_string	string	required	Name of the processing string. Possible values come from /api/selection endpoint.
from_run	int	required together with to_run. Both can be substituted with either runs or latest.	Runs filter: lower bound.
to_run	int	required together with from_run. Both can be substituted with either runs or latest.	Runs filter: upper bound.
runs	array	required but can be substituted with from_run, to_run or latest.	Runs filter: comma separated list of runs to return data for.
latest	int	required but can be substituted with from_run, to_run or runs.	Runs filter: return latest N runs.
series	string	optional	Specific name of the series to return. If not specified, all series will be returned based on selection.
series_id	int	optional	Specific series ID. IDs come from /api/plot_selection endpoint.

Keep in mind that runs can be filtered in 3 ways:

• Range (from_run, to_run)
• List of specific runs (runs)
• Last N runs (latest)

Exactly one way must be used to filter out required runs.

Sample query: /api/data?subsystem=PixelPhase1&pd=SingleElectron&processing_string=09Aug2019_UL2017&latest=50

/api/selection

This endpoint returns a nested object of possible subsystem, primary dataset and processing string combinations. This endpoint takes no arguments.

Sample (shortened) response:

{
  "CSC":{
    "Cosmics":[
      "PromptReco"
    ],
    "JetHT":[
      "09Aug2019_UL2017"
    ]
  },
  "Muons":{
    "ZeroBias":[
      "09Aug2019_UL2017",
      "PromptReco"
    ]
  }
}

/api/plot_selection

This endpoint is very similar to /api/selection, but it is one level deeper. It also includes the names and IDs of all available series. Names and IDs can be used to retrieve only required plots using series or series_id parameters in /api/data endpoint. This endpoint takes no arguments.

Sample (shortened) response:

{
  "CSC":{
    "Cosmics":{
      "PromptReco":[
        {
          "id":4426,
          "name":"AnodeCatodheTimeDiff"
        }
      ]
    }
  }
}

/api/runs

This endpoint returns a list of all run numbers present in the HDQM database. This endpoint takes no arguments.

/api/expand_url

For performance reasons, DQM GUI URLs for each data point are not returned by the /api/data endpoint. However, the data point IDs are returned and using this endpoint they can be exchanged for an actual DQM GUI URL.

Possible arguments:

Param	Data type	Required/optional	Description
data_point_id	int	required	An ID referring to a single data point returned by the /api/data endpoint.
url_type	string	required	Type of the DQM GUI URL required. All possible values are: main_gui_url, main_image_url, optional1_gui_url, optional1_image_url, optional2_gui_url, optional2_image_url, reference_gui_url, reference_image_url.