Logging.md

Logging

The Snowflake Connector for .NET uses log4net as the logging framework.

Here is a sample app.config file that uses log4net

  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
  </configSections>

  <log4net>
    <appender name="MyRollingFileAppender" type="log4net.Appender.RollingFileAppender">
      <file value="snowflake_dotnet.log" />
      <appendToFile value="true"/>
      <rollingStyle value="Size" />
      <maximumFileSize value="10MB" />
      <staticLogFileName value="true" />
      <maxSizeRollBackups value="10" />
      <layout type="log4net.Layout.PatternLayout">
        <!-- <header value="[DateTime]  [Thread]  [Level]  [ClassName] Message&#13;&#10;" /> -->
        <conversionPattern value="[%date] [%t] [%-5level] [%logger] %message%newline" />
      </layout>
    </appender>

    <root>
      <level value="ALL" />
      <appender-ref ref="MyRollingFileAppender" />
    </root>
  </log4net>

Easy logging

The Easy Logging feature lets you change the log level for all driver classes and add an extra file appender for logs from the driver's classes at runtime. You can specify the log levels and the directory in which to save log files in a configuration file (default: sf_client_config.json).

You typically change log levels only when debugging your application.

Note This logging configuration file features support only the following log levels:

• OFF
• ERROR
• WARNING
• INFO
• DEBUG
• TRACE

This configuration file uses JSON to define the log_level and log_path logging parameters, as follows:

{
  "common": {
    "log_level": "INFO",
    "log_path": "c:\\some-path\\some-directory"
  }
}

where:

• log_level is the desired logging level.
• log_path is the location to store the log files. The driver automatically creates a dotnet subdirectory in the specified log_path. For example, if you set log_path to c:\logs, the drivers creates the c:\logs\dotnet directory and stores the logs there.

The driver looks for the location of the configuration file in the following order:

• CLIENT_CONFIG_FILE connection parameter, containing the full path to the configuration file (e.g. "ACCOUNT=test;USER=test;PASSWORD=test;CLIENT_CONFIG_FILE=C:\\some-path\\client_config.json;")
• SF_CLIENT_CONFIG_FILE environment variable, containing the full path to the configuration file.
• .NET driver/application directory, where the file must be named sf_client_config.json.
• User’s home directory, where the file must be named sf_client_config.json.

Note To enhance security, the driver no longer searches a temporary directory for easy logging configurations. Additionally, the driver now requires the logging configuration file on Unix-style systems to limit file permissions to allow only the file owner to modify the files (such as chmod 0600 or chmod 0644).

To minimize the number of searches for a configuration file, the driver reads the file only for:

• The first connection.
• The first connection with CLIENT_CONFIG_FILE parameter.

The extra logs are stored in a dotnet subfolder of the specified directory, such as C:\some-path\some-directory\dotnet.

If a client uses the log4net library for application logging, enabling easy logging affects the log level in those logs as well.