logging-log4j-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ceki Gulcu <c...@qos.ch>
Subject Re: [jira] [Created] (LOG4J2-1375) Update SLF4J from 1.7.13 to 1.7.21
Date Sat, 23 Apr 2016 14:18:23 GMT
You are welcome.

In the principle, the  event loss issue (fixed by event replay 
post-initialization) depends on the time it takes for the underlying 
implementation to initialize. Unless you can guarantee that log4j2 
initializes instantly**, during SLF4J initialization event loss will 
occur with log4j2 as well. Note the event loss issue is limited to 
applications using slf4j which are multi-threaded early on.

 > Would you mind sharing which applications perform reflection on
 > the org.slf4j.Logger implementation (and why)?

The typical example is Spring which may do reflection on logger 
instances. If the org.slg4j.Logger implementation offers the 
log(org.slf4j.event.LoggingEvent) method, then the 
org.slf4j.event.LoggingEvent interface must exist on the class path. 
Otherwise, the Spring initialization will fail. The 
org.slf4j.event.LoggingEvent interface was introduced in slf4j-api 
version 1.7.15. It follows that if you decide to make use of the slf4j 
replay feature, then log42 will de facto depend on slf4j version 1.7.15 
both at compile and runtime.

--
Ceki

**I am presuming here that log4j2 initializes when it creates and 
returns its first Logger.

On 4/23/2016 15:54, Remko Popma wrote:
> ...and thank you for the info, Ceki, that is certainly helpful!
>
> Remko
>
> On Saturday, 23 April 2016, Remko Popma <remko.popma@gmail.com
> <mailto:remko.popma@gmail.com>> wrote:
>
>     Question: does the replay support solve a problem in SLF4J or in
>     Logback initialization?
>
>     If the latter, then perhaps there's no need to implement the new
>     method since log4j-slf4j-impl binds to log4j2 anyway, no?
>
>     Remko
>
>     Sent from my iPhone
>
>      > On 2016/04/23, at 22:12, Ceki Gulcu <ceki@qos.ch <javascript:;>>
>     wrote:
>      >
>      > Hello,
>      >
>      > For your information, slf4j-api version 1.7.21 will work with
>     current versions of log4j2 just fine albeit without replay support.
>     For replay support, log4j2's implementation of org.slf4j.Logger
>     interface needs to have a method with the signature
>     log(org.slf4j.event.LoggingEvent) in which case events generated
>     during SLF4J initialization will be replayed. Note that if log4j2's
>     Logger implementation chooses to implement the aforementioned log
>     method, log42 will de facto depend on SLF4J version 1.7.15 and later
>     both at compile and *runtime*.
>      >
>      > The runtime dependency might seem surprising but some
>     applications perform reflection on the org.slf4j.Logger
>     implementation which will fail without slf4j-api 1.7.15 or later
>     being present on the classpath.
>      >
>      > I hope this helps,
>      >
>      > --
>      > Ceki
>      >
>      >> On 4/23/2016 14:47, Ralph Goers wrote:
>      >> We are not fully compatible with this version of SLF4J.  It had some
>      >> initialization race conditions so Substitute Loggers were invented.
>      >> Anyway, there is a new interface we need to implement.
>      >>
>      >> Ralph
>      >>
>      >> Begin forwarded message:
>      >>
>      >>> *From:* "Remko Popma (JIRA)" <jira@apache.org <javascript:;>
>     <mailto:jira@apache.org <javascript:;>>>
>      >>> *Date:* April 23, 2016 at 4:13:12 AM MST
>      >>> *To:* log4j-dev@logging.apache.org <javascript:;>
>     <mailto:log4j-dev@logging.apache.org <javascript:;>>
>      >>> *Subject:* *[jira] [Closed] (LOG4J2-1375) Update SLF4J from
>     1.7.13 to
>      >>> 1.7.21*
>      >>> *Reply-To:* "Log4J Developers List"
>     <log4j-dev@logging.apache.org <javascript:;>
>      >>> <mailto:log4j-dev@logging.apache.org <javascript:;>>>
>      >>>
>      >>>
>      >>>    [
>      >>>
>     https://issues.apache.org/jira/browse/LOG4J2-1375?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
>      >>> ]
>      >>>
>      >>> Remko Popma closed LOG4J2-1375.
>      >>> -------------------------------
>      >>>   Resolution: Fixed
>      >>>
>      >>>> Update SLF4J from 1.7.13 to 1.7.21
>      >>>> ----------------------------------
>      >>>>
>      >>>>               Key: LOG4J2-1375
>      >>>>               URL:
>     https://issues.apache.org/jira/browse/LOG4J2-1375
>      >>>>           Project: Log4j 2
>      >>>>        Issue Type: Improvement
>      >>>>        Components: SLF4J Bridge
>      >>>>  Affects Versions: 2.5
>      >>>>          Reporter: Remko Popma
>      >>>>          Assignee: Remko Popma
>      >>>>           Fix For: 2.6
>      >>>>
>      >>>>
>      >>>> Update SLF4J from 1.7.13 to 1.7.21
>      >>>
>      >>>
>      >>>
>      >>> --
>      >>> This message was sent by Atlassian JIRA
>      >>> (v6.3.4#6332)
>      >>>
>      >>>
>     ---------------------------------------------------------------------
>      >>> To unsubscribe, e-mail:
>     log4j-dev-unsubscribe@logging.apache.org <javascript:;>
>      >>> <mailto:log4j-dev-unsubscribe@logging.apache.org <javascript:;>>
>      >>> For additional commands, e-mail:
>     log4j-dev-help@logging.apache.org <javascript:;>
>      >>> <mailto:log4j-dev-help@logging.apache.org <javascript:;>>
>      >
>      > ---------------------------------------------------------------------
>      > To unsubscribe, e-mail: log4j-dev-unsubscribe@logging.apache.org
>     <javascript:;>
>      > For additional commands, e-mail:
>     log4j-dev-help@logging.apache.org <javascript:;>
>      >
>

---------------------------------------------------------------------
To unsubscribe, e-mail: log4j-dev-unsubscribe@logging.apache.org
For additional commands, e-mail: log4j-dev-help@logging.apache.org


Mime
View raw message