******************
cuSOLVERMP Logging
******************

cuSOLVERMP logging mechanism can be enabled and configured before launching the target application using the environmental variables `CUSOLVERMP_LOG_LEVEL`,
`CUSOLVERMP_LOG_MASK` and `CUSOLVERMP_LOG_FILE`. It is also possible to enable and configure the logging 
at runtime using the :ref:`logging API <cusolverMpLoggingAPI-label>`.

.. note :: The logging will generate one file (or stream of data) per process. Enabling the logging on a large run while providing output
    directories on distributed file system can put the file system under pressure. Consult with the system administration of your system for support.

.. _cusolvermp_log_level-label:

----------------------------
:code:`CUSOLVERMP_LOG_LEVEL`
----------------------------

Use `CUSOLVERMP_LOG_LEVEL=<level>` to set the value of the logging level, where level
is one of the values in the table below:

.. csv-table::
   :header: "Value", "Meaning", "Description"
   :widths: auto

    "0", "Off", "Logging is disabled (default)."
    "1", "Error", "Only errors will be logged."
    "2", "Trace", "API calls that launch CUDA kernels will log the value of their parameters and other relevant information."
    "3", "Hints", "Hints that can potentially improve the application's performance."
    "4", "Info", "Provides general information about the library execution."
    "5", "API Trace", "API calls will log the value of their parameters and other relevant information."

---------------------------
:code:`CUSOLVERMP_LOG_MASK`
---------------------------

Use `CUSOLVERMP_LOG_MASK=<level>` to set the value of the logging mask, where level
is a combination of the following values:

.. csv-table::
   :header: "Value", "Meaning", "Description"
   :widths: auto

    "0", "Off", "No filter (default)."
    "1", "Error", "Only errors will be logged."
    "2", "Trace", "API calls that launch CUDA kernels will log the value of their parameters and important information."
    "4", "Hints", "Hints that can potentially improve the application's performance."
    "8", "Info", "Provides general information about the library execution."
    "16", "API Trace", "API calls will log the value of their input parameters and other relevant information."

---------------------------
:code:`CUSOLVERMP_LOG_FILE`
---------------------------

Use `CUSOLVERMP_LOG_FILE=<file_name>` where file name is a path to a logging file. File name may contain `%i`, that will be replaced with the process id. E.g `<file_name>_%i.log`.

If `CUSOLVERMP_LOG_FILE` is not defined, the log messages are printed to stdout.