That's what I meant, I didn't make myself clear. For example, we could offer a simple binary layout:
time stamp (8 bytes)
level int (4 bytes)
thread ID (4 bytes) - Thread names in separate file
Logger ID (4 bytes) - Logger names in separate file. 
message length (4 bytes)
message type (2 bytes)
message data (variable length)
throwable length (4 bytes)
throwable data (variable length)

It's a very different approach to logging. On the plus side, this would be extremely compact and very fast to write. 

On the other hand it would require a separate tool to decode/display the data in human readable form. Such a tool should handle text messages out of the box, but for custom messages I image there could be some plugin mechanism for custom decoders. 

All very interesting...

Sent from my iPhone

On 2016/03/03, at 0:01, Matt Sicker <> wrote:

That's what I thought at first, but he means non-human readable formats since we all use tools to parse logs as it is (Splunk and ELK are the big two I know of).

On 2 March 2016 at 02:15, Remko Popma <> wrote:
Re: binary logging, I think he's talking about providing an API to log objects directly into byte buffers without turning them into Strings first. 

were created with that in mind and should be a good step in that direction. 

Sent from my iPhone

On 2016/03/02, at 15:11, Gary Gregory <> wrote:

Well, I've often wondered about creating a binary format but it seems that you could use JSON+ZIP or BSON and get most of the advantages.


On Tue, Mar 1, 2016 at 9:12 PM, Matt Sicker <> wrote:
One other interesting thing I learned is that improper use of logging is a huge source of performance problems. The GC-free parameterized message factory will help with one aspect of that (I suggested parameterized messages, but he countered with the Object[] that is created), and encouraging users to use a Supplier<String> instead of passing parameters should help as well (especially when those parameters have to be computed). He had some strong criticisms of logging APIs promoting bad practices which stems all the way back to log4j1 and affects pretty much every logging API in Java (some criticisms were actually outdated or didn't consider newer features of the API like markers and the huge amount of filters available).

His other big idea was promoting the use of binary logging formats because humans rarely read the raw log files as it is, but it's not like there's a standard way to do that.

Now I kinda wonder if he'll find this thread one day and tell me how I misinterpreted him or something. ;)

On 1 March 2016 at 22:28, Matt Sicker <> wrote:
Alright, I learned some interesting things. I'm going to get us some tools we can use to try and profile this. Otherwise, he did suggest trying out this project:

On 1 March 2016 at 19:31, Matt Sicker <> wrote:
So far he's said something about using lambdas for lazy evaluation (though I don't think that would actually help us at all). I'll try to talk to him one-on-one afterward to delve more into this.

On 1 March 2016 at 18:13, Ralph Goers <> wrote:
Actually, most of the tests have the commands in the comments right in the class. Just cut and past.


On Mar 1, 2016, at 1:43 PM, Matt Sicker <> wrote:

I can't even figure out how to execute the simple perf test class. IntelliJ gives me some annotation processing error, and doing it from the command line is turning into a classpath nightmare to figure out what jars are needed to execute the test manually.

On 1 March 2016 at 11:34, Gary Gregory <> wrote:

Before the talk: Hi, I'm Remko, I help on Apache Log4j, are you available after the preso to talk about some issue we are seeing?


On Mar 1, 2016 8:29 AM, "Matt Sicker" <> wrote:
I'm attending a JUG meetup tonight with Kirk Pepperdine presenting. It's supposed to be a Java performance workshop type of thing, so if you've got a decent way to ask about it, I could see if he can help figure out this regression. I can at least show off the SimplePerfTest and any microbenchmarks we have.

On 28 February 2016 at 11:54, Matt Sicker <> wrote:
Take a look at the git bisect command. Might help you find which changes caused the problem.

On Sunday, 28 February 2016, Gary Gregory <> wrote:

Thank you for digging in Remko. This is will be a nice theme to publicize when you get it figured out.


On Feb 28, 2016 4:08 AM, "Remko Popma" <> wrote:
After removing the potential impact of appenders and layouts by testing with log4j-core\src\test\resources\perf-CountingNoOpAppender.xml and org.apache.logging.log4j.core.async.perftest.SimplePerfTest, I've confirmed my initial numbers:

2.0: 7.5M ops/sec
2.1: 6M ops/sec
2.2: 6M ops/sec
2.3: 6M ops/sec
2.4: 4.5M ops/sec
2.5: 4M ops/sec
2.6: 2M ops/sec

I tried reverting various changes made to AsyncLogger since 2.0, performance improves a little up to 4M ops/sec.
However, when completely reverting AsyncLogger source to the 2.0 version, performance is back to 7.5M ops/sec.

I'll try starting from the 2.0 source and getting back to 2.6 functionality without losing performance...
(Lengthy process...)

On Sat, Feb 27, 2016 at 12:18 PM, Remko Popma <> wrote:
This is the PerfTestDriver test class (in log4j-core/test, package ...async.perf). 
Mainly perf3PlainNoLocation.xml:
RollingRandomAccessFileAppender, PatternLayout, all loggers are AsyncLoggers, logging a simple string without parameters. 

Profiling with YourKit did not tell me anything useful. 

I'm now eliminating the effect of Layouts/Appenders, using CountingNoOpAppender, and seeing similar numbers. So this seems to be mostly an issue in AsyncLogger. 

I'll let you know when I find out more. 
There's a lot of trial and error here, so this may take a while...


Sent from my iPhone

On 2016/02/26, at 21:02, Mikael Ståldal <> wrote:

Which components (appenders, layouts) are involved in the tests? Would it be possible to do some profiling to see if there is any particular component which is to blame?

On Fri, Feb 26, 2016 at 12:51 PM, Remko Popma <> wrote:
To give you some rough impression on concrete numbers for this trend:
2.0: ~6M ops/sec
2.1-2.2: ~5M ops/sec
2.3-2.4: ~3-4M ops/sec
2.5: ~3M ops/sec
2.6: ~2M ops/sec

On Friday, 26 February 2016, Remko Popma <> wrote:
You're absolutely right. I still have quite a few unit tests to add. 

Initial perf testing shows a downward trend in Async Logger performance with every release. (Logging simple string messages without params.) This is worrisome and I'm focusing on figuring that out first: this will likely involve additional code changes and I'll add more tests after that. 

Sent from my iPhone

On 2016/02/26, at 10:38, Gary Gregory <> wrote:

Wow, I love the activity we are seeing toward 2.6! All the perf work on top of an existing sizable change set. Very exciting indeed.

There sure are a lot of changes coming in. I hope that we all can pitch in to make sure most if not all of these changes get code coverage from unit tests. I've not checked closely, but it seems like we may not have good coverage _yet_, or do I have the wrong impression?

I want to make sure we keep our stability in tip top shape :-) and that we have no regression from previous releases.


Mikael Ståldal
Senior software developer

Magine TV
Grev Turegatan 3  | 114 46 Stockholm, Sweden  |

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