Hi all, we have upgraded the log4net version from 1.2.10 to the newest version 2.0.14 and are now facing performace issues. I already have done some investigation looking at the log4net code.
With the ticket LOG4NET-205<https://issues.apache.org/jira/browse/LOG4NET-205> a change has been introduced, which makes log4net not acceptable for us in terms of performance. (Commit 5c023f6a22bfb93873a5ce0d6f5ac7e7275e2914) The change has been done in order to be able to use UserName and Identity in the PropertyFilter. It adds 'internal' properties representing the UserName and Identity to the m_compositeProperties so that they are now accessible in the PropertyFilter. That works as intended so far. See the attached diff illustrating the change. The problem is, that fetching the UserName from the system is pretty expensive. With the change above UserName is fetched always, regardless of whether we use UserName or not. I did some benchmarking and this change slowed down logging by a factor of 60. I also don’t see any way to get around this by changing the configuration. I believe this can only be fixed by changing code. I would suggest, rather than adding 'internal' properties to m_compositeProperties, we should make the function LoggingEvent.LookupProperty to look after the native properties, when corresponding keys are specified. E.g. when the key "UserName" is specified, we could return the value of the property LoggingEvent.UserName etc. In the meantime we want to use a changed version of log4net for our purposes. I wonder, whether this change could be integrated into the official version? I’ve never contributed to a public github project before, so don’t know how to proceed really. Thanks, Denis This is the historic change causing the problem. [cid:image001.png@01D8274E.AA9B33A0] -- Denis Petker Next Generation Solutions | 8BM3 Rohde & Schwarz GmbH & Co. KG Hanomaghof 1 | 30449 Hanover Phone: +49 511 678 07 146 | Fax: +49 511 678 07 200 Internet: www.rohde-schwarz.com<http://www.rohde-schwarz.com/> ------------------------------------------------------------ Geschäftsführung / Executive Board: Christian Leicher (Vorsitzender / Chairman), Peter Riedel, Sitz der Gesellschaft / Company's Place of Business: München, Registereintrag / Commercial Register No.: HRA 16 270, Persönlich haftender Gesellschafter / Personally Liable Partner: RUSEG Verwaltungs-GmbH, Sitz der Gesellschaft / Company's Place of Business: München, Registereintrag / Commercial Register No.: HRB 7 534, Umsatzsteuer-Identifikationsnummer (USt-IdNr.) / VAT Identification No.: DE 130 256 683, Elektro-Altgeräte Register (EAR) / WEEE Register No.: DE 240 437 86
