what permissions are needed for writing to uls logs?

Question

We have creates a webpart and in the catch block we are writing logs to uls.

My concern is regarding permission to write to this log. Will users with read-only access to sharepoint face no issue?

 private void WriteToULS(TraceSeverity Level, string OutStr)
        {
            SPDiagnosticsService.Local.WriteTrace(0, new SPDiagnosticsCategory("Portal Error", Level, EventSeverity.Error), TraceSeverity.Unexpected, OutStr, null);
        }

I would also like to know if it a good practice to use:

private void WriteToULS(TraceSeverity Level, string OutStr)
            {
 SPSecurity.RunWithElevatedPrivileges(delegate()
                {
                SPDiagnosticsService.Local.WriteTrace(0, new SPDiagnosticsCategory("Portal Error", Level, EventSeverity.Error), TraceSeverity.Unexpected, OutStr, null);
 }); 
            }

in the code for all webparts.

Answer 1

Call the below method ,this will ensure you are have correct/appropriate permissions while users with read permissions write to log file.

SPSecurity RunWithElevatedPriviledges{
LogData();
}

public static void LogData(string categoryName, Level type, string section, string message, string exception)
{
    try
    {
        /*Log SharePoint*/
        SPDiagnosticsService diagnosticsService = SPDiagnosticsService.Local;
        diagnosticsService.WriteTrace(0,
                                      new SPDiagnosticsCategory(categoryName, TraceSeverity.Unexpected,
                                                                EventSeverity.Error),
                                      TraceSeverity.Unexpected, exception, exception);
    }
    catch
    {
        throw new Exception("ExceptionManager.LogData > Failed !");
    }
}

Refer for ULS logs details if required : where see the log SPDiagnosticsService WriteTrace

Answer 2

Users with read only access won't be able to write to ULS. Write the code inside RunWithElevatedPreviliges delegate