Ralph, Was your comment about BasicContextSelector me and my quest to get V2
to run as well as V1 on my slow single core J2ME env?
My test run with AsyncLogger blew up. This J2ME VM does not have reflection.
Guessing that disruptor uses reflection to cast methods/objects (bottom).
This leaves me with just one more experiment to get V2 to perform as well as
V1: RollingFile with bufferedIO=false
RE: MDC, no we'll not use any location info, just passing values like username
(example) and similar constant values from each transaction initiation into
the log.
#0 ERROR > Error occurred while trying to activate bundle!
java.lang.ExceptionInInitializerError
at java.lang.J9VMInternals.initialize(J9VMInternals.java:233)
at java.lang.Class.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1279)
at
com.prosyst.mbs.impl.framework.BundleImpl.startIt(BundleImpl.java:4287)
at
com.prosyst.mbs.impl.framework.BundleImpl.simpleStart(BundleImpl.java:1744)
at
com.prosyst.mbs.impl.framework.BundleImpl.start0(BundleImpl.java:1642)
at
com.prosyst.mbs.impl.framework.BundleImpl.start0(BundleImpl.java:1515)
at com.prosyst.mbs.impl.framework.BundleImpl.start(BundleImpl.java:1350)
at com.prosyst.mbs.impl.framework.BundleImpl.start(BundleImpl.java:1060)
at
com.prosyst.mbs.impl.framework.module.boot.BootImpl.start(BootImpl.java:869)
at
com.prosyst.mbs.impl.framework.module.boot.BootImpl.executeBoot(BootImpl.java:386)
at
com.prosyst.mbs.impl.framework.module.boot.BootImpl.processDefaultBoot(BootImpl.java:163)
at
com.prosyst.mbs.impl.framework.module.boot.BootImpl.start(BootImpl.java:93)
at
com.prosyst.mbs.impl.framework.FrameworkLauncher.start(FrameworkLauncher.java:1194)
at
com.prosyst.mbs.impl.framework.FrameworkLauncher.finishLaunch(FrameworkLauncher.java:501)
at
com.prosyst.mbs.impl.framework.FrameworkLauncher.launch(FrameworkLauncher.java:476)
at java.lang.reflect.AccessibleObject.invokeV(AccessibleObject.java:195)
at java.lang.reflect.Method.invoke(Method.java:242)
at
com.prosyst.mbs.impl.framework.Start.processFrameworkLaunch(Start.java:196)
at com.prosyst.mbs.impl.framework.Start.main(Start.java:82)
Caused by: java.lang.IllegalStateException: Unexpected error building Logger:
null
at com.att.dlc.logging.LoggerFactory.buildLogger(LoggerFactory.java:92)
at com.att.dlc.logging.LoggerFactory.getLogger(LoggerFactory.java:34)
at com.att.dlc.osgi.Activator.<clinit>(Activator.java:120)
at java.lang.J9VMInternals.initializeImpl(Native Method)
at java.lang.J9VMInternals.initialize(J9VMInternals.java:211)
... 19 more
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.AccessibleObject.invokeV(AccessibleObject.java:197)
at java.lang.reflect.Constructor.newInstance(Constructor.java:204)
at com.att.dlc.logging.LoggerFactory.buildLogger(LoggerFactory.java:89)
... 23 more
Caused by: java.lang.ExceptionInInitializerError
at java.lang.J9VMInternals.initialize(J9VMInternals.java:233)
at
org.apache.logging.log4j.core.async.AsyncLogger.calculateRingBufferSize(AsyncLogger.java:123)
at
org.apache.logging.log4j.core.async.AsyncLogger.<clinit>(AsyncLogger.java:89)
at java.lang.J9VMInternals.initializeImpl(Native Method)
at java.lang.J9VMInternals.initialize(J9VMInternals.java:211)
at
org.apache.logging.log4j.core.async.AsyncLoggerContext.newInstance(AsyncLoggerContext.java:51)
at
org.apache.logging.log4j.core.LoggerContext.getLogger(LoggerContext.java:274)
at
org.apache.logging.log4j.core.LoggerContext.getLogger(LoggerContext.java:255)
at
org.apache.logging.log4j.core.LoggerContext.getLogger(LoggerContext.java:51)
at org.apache.logging.log4j.LogManager.getLogger(LogManager.java:364)
at com.att.dlc.logging.Log4jLogger.<init>(Log4jLogger.java:38)
at com.att.dlc.logging.Log4jLogger.<init>(Log4jLogger.java:46)
at java.lang.reflect.AccessibleObject.invokeV(AccessibleObject.java:195)
... 25 more
Caused by: java.lang.RuntimeException: Unable to load unsafe
at com.lmax.disruptor.util.Util.<clinit>(Util.java:112)
at java.lang.J9VMInternals.initializeImpl(Native Method)
at java.lang.J9VMInternals.initialize(J9VMInternals.java:211)
... 37 more
Caused by: java.security.PrivilegedActionException:
java.lang.NoSuchFieldException: theUnsafe
at
java.security.AccessController.doPrivileged(AccessController.java:259)
at com.lmax.disruptor.util.Util.<clinit>(Util.java:108)
... 39 more
Caused by: java.lang.NoSuchFieldException: theUnsafe
at java.lang.Class.getDeclaredFieldImpl(Native Method)
at java.lang.Class.getDeclaredField(Class.java:487)
at com.lmax.disruptor.util.Util$1.run(Util.java:102)
at com.lmax.disruptor.util.Util$1.run(Util.java:99)
at
java.security.AccessController.doPrivileged(AccessController.java:255)
... 40 more
-----Original Message-----
From: Ralph Goers [mailto:ralph.go...@dslextreme.com]
Sent: Monday, July 29, 2013 11:05 AM
To: Log4J Users List
Subject: Re: reflection? RE: async logger on slow single core env performs 50%
worse than log4j v1
This probably warrants an enhancement to Log4jContextFactory. I can imagine
other use cases where defaulting to BasicContextSelector also makes sense.
Ralph
On Jul 29, 2013, at 8:02 AM, Ralph Goers wrote:
> In your environment I would definitely recommend using BasicContextSelector
> as you are unlikely to have need for multiple LoggerContexts.
>
> Ralph
>
> On Jul 29, 2013, at 7:08 AM, SMITH, CURTIS wrote:
>
>> Hi guys, I mentioned this observation last week, that my embedded single
>> core env, the VM also does not support reflection. Is reflection used in
>> the hot path of logging that might be affecting my testing of V2 using more
>> CPU than v1?
>>
>>>>> LOGGER.debug("sun.reflect.Reflection is not installed"); //
>>>>> ï∞ƒ----------------------------
>>
>> I get this log at VM startup time.
>>
>> Curt
>> ------------------------
>>
>>
>> package org.apache.logging.log4j.core.selector;
>>
>> public class ClassLoaderContextSelector implements ContextSelector {
>>
>> private static void setupCallerCheck() {
>> 223 try {
>> 224 final ClassLoader loader = Loader.getClassLoader();
>> 225 final Class clazz =
>> loader.loadClass("sun.reflect.Reflection");
>> 226 final Method[] methods = clazz.getMethods();
>> 227 for (final Method method : methods) {
>> 228 final int modifier = method.getModifiers();
>> 229 if (method.getName().equals("getCallerClass") &&
>> Modifier.isStatic(modifier)) {
>> 230 getCallerClass = method;
>> 231 break;
>> 232 }
>> 233 }
>> 234 } catch (final ClassNotFoundException cnfe) {
>> 235 LOGGER.debug("sun.reflect.Reflection is not installed");
>> // ï∞ƒ----------------------------
>> 236
>>
>> -----Original Message-----
>> From: Remko Popma [mailto:rem...@yahoo.com]
>> Sent: Saturday, July 27, 2013 5:40 AM
>> To: Log4J Users List; Remko Popma
>> Subject: Re: async logger on slow single core env performs 50% worse than
>> log4j v1
>>
>> I quickly reviewed the code and as far as I can tell:
>> * only the following places in Log4j-2 will create a permanent thread in
>> addition to your application threads:Â AsyncLoggers, AsyncAppenders,
>> o.a.l.l.c.net.SocketServer, o.a.l.l.c.net.UDPSocketServer andÂ
>> o.a.l.l.c.helpers.*CachedClock
>> * synchronous logging will not create any threads
>> * RollingFile creates a short-lived thread for the roll-over, *only*Â if the
>> old file needs to be compressed to a .zip or .gz file (the file rename
>> action is synchronous)
>>
>> So I'm thinking that the difference in CPU usage is caused by something
>> other than threads or async logging.
>> I'd be interested in your answers to my questions below.
>>
>> Best regards,
>> Remko
>>
>>
>> ________________________________
>> From: Remko Popma <rem...@yahoo.com>
>> To: Log4J Users List <log4j-user@logging.apache.org>
>> Sent: Saturday, July 27, 2013 12:53 PM
>> Subject: Re: async logger on slow single core env performs 50% worse than
>> log4j v1
>>
>>
>> I don't think we've ever done any performance testing on the kind of
>> environment you describe, so this is great feedback, thanks!
>>
>> First, configuration via XML instead of sys props is on the todo list.
>>
>> Second, you mentioned you use system property "AsyncLoggerContextSelector"
>> to switch on AsyncLoggers.
>> This is incorrect. The correct key is "Log4jContextSelector" (and that would
>> explain why removing this setting made no difference).
>>
>> Third, if I understand correctly you are essentially logging to a
>> memory-mapped file. In that case any buffering is just wasting CPU
>> resources, so you should not use the Fast*File appenders as their buffering
>> cannot be switched off. (Non-Fast) FileAppenders also use bufferedIO=true by
>> default, but you can switch this off in config. I would expect this to save
>> some CPU.
>>
>> On that note, you mentioned CPU usage as your performance measure. Is that
>> the most important number? Do you have any throughput/latency goals?
>> Do you have any tools on your platform to see what the CPU is doing? Which
>> threads are busy for example?
>>
>> In terms of GC, making all loggers Async has a small benefit in that it
>> re-uses log event objects.
>>
>>
>> I am still intrigued by the difference in CPU usage you mention between
>> log4j-1.2 and 2.0. Is your application code exactly the same? Or do you use
>> the pattern formats that are now available in log4j-2.0?
>>
>> Regards,
>> Remko
>>
>>
>> ________________________________
>> From: "SMITH, CURTIS" <cs0...@att.com>
>> To: Log4J Users List <log4j-user@logging.apache.org>
>> Sent: Saturday, July 27, 2013 6:55 AM
>> Subject: RE: async logger on slow single core env performs 50% worse than
>> log4j v1
>>
>>
>> LOL well that's obvious now. :) It was more a case of wishful thinking
>> and why not give it a "try".  But it's still odd that my attempts to
>> slim it down It's still 2x worse than v1. Something else is in play.
>>
>> curt
>>
>> -----Original Message-----
>> From: Ralph Goers [mailto:ralph.go...@dslextreme.com]
>> Sent: Friday, July 26, 2013 5:34 PM
>> To: Log4J Users List
>> Subject: Re: async logger on slow single core env performs 50% worse than
>> log4j v1
>>
>> I'm curious why you are even trying to use Async anything with a single core
>> environment (unless it is hyper-threaded). Only 1 thread can be active at a
>> time so when you switch threads the active thread will just stop. This won't
>> gain you any additional throughput but you will still incur the additional
>> overhead of thread management and locking.
>>
>> Ralph
>>
>> On Jul 26, 2013, at 1:55 PM, SMITH, CURTIS wrote:
>>
>>> I removed System.setProperty("AsyncLoggerContextSelector",
>>> "org.apache.logging.log4j.core.async.AsyncLoggerContextSelector");
>>> No change in CPU, but going from FastRollingFile to RollingFile I got back
>>> 10% of my lost CPU. Still at 40% CPU where v1 runs at 20%.
>>>
>>> I would like to get down to the equivalent behavior as we got from log4j
>>> v1, then try v2 features to get it better. Since I'm still seeing worse
>>> performance, I'm guessing that there's still one or more threads under the
>>> hood vs V1 with:Â sync Logger and RollingFile.
>>>
>>> Any guesses for me to try?
>>>
>>> Tnx curt
>>>
>>> _____________________________________________
>>> From: SMITH, CURTIS
>>> Sent: Friday, July 26, 2013 1:16 PM
>>> To: log4j-user@logging.apache.org
>>> Subject: async logger on slow single core env performs 50% worse than log4j
>>> v1
>>>
>>>
>>> I suspect a slow single core env is a new scenario for v2 and async
>>> logger.  My view is that there's a mis match between v2's async logger
>>> thread design that works great on multi-core envs and this embedded slow
>>> single core env...  Sooo I need to try a few different configurations to
>>> see what does run best on a slow single core...
>>>
>>> But I need your tips as to what I might change / tune to get v2 to perform
>>> as good or better than v1 in a single core env.
>>>
>>> FWIW: log4j v1 ran my standard use case test averaging 20% CPU. Log4j
>>> v2 ran at 50% CPU, so more than 2x worse.
>>>
>>> Our business logic is highly threaded so any subsystem that has a "hot"
>>> thread like this config that has 5 loggers and 3 appenders I might be
>>> shooting myself in the foot. You know this new design the best so I'm
>>> open as to what to pick and choose from v2 that is likely to perform the
>>> best?
>>>
>>> FYI:Â I feel using system properties vs exclusively using declarative
>>> configuration all within the log4j2.xml separates out configuration. I'd
>>> prefer to not have to use system properties for any configuration.
>>>
>>> My first experiment will be to remove the async logger property.
>>>
>>> Any thoughts re the FastRollingFile appender or any other tuning that might
>>> be better for a single core env. It's a slow Arm v5 or so, pretty old and
>>> lacking the better context switching features of newer chips. The VM is
>>> also slow, IBM J9 J2ME JDK1.6.  Benchmarking the J9 vs Oracle J2ME, J9
>>> is real slow and poor at thread context switching. But you get what you
>>> pay for, J9 is also real cheap.
>>>
>>> ******
>>> ******
>>> Note: the log files are on /tmp a memory FS in our env. So the worst
>>> case of a synchronous logger from the same thread as the logger.debug call
>>> may not perform that badly thanks to Linux FS buffering and memfs having
>>> low latency. Just mentioning.
>>>
>>>
>>> // Manually set the log4j v2 async logger tuning parameters here. DLA
>>> does not have a system property
>>> Â Â Â Â Â Â Â Â // property file
>>> Â Â Â Â Â Â Â Â System.setProperty("AsyncLoggerContextSelector",
>>> "org.apache.logging.log4j.core.async.AsyncLoggerContextSelector");
>>> Â Â Â Â Â Â Â Â System.setProperty("AsyncLogger.RingBufferSize",
>>> "128");Â Â Â Â // min size permissable to keep memory low
>>> Â Â Â Â Â Â Â Â System.setProperty("AsyncLogger.WaitStrategy",
>>> "Block");Â Â Â Â // less CPU, better for embedded env
>>> Â Â Â Â Â Â Â Â System.setProperty("log4j2.disable.jmx", "true");Â
>>> Â Â Â Â Â Â Â Â Â Â Â // saves on a jmx jar and we don't use JMX
>>> anyway
>>>
>>> <?xml version="1.0" encoding="UTF-8"?>
>>> <configuration status="trace" level="trace" >Â <!-- log4j v2 debug add
>>> these: status="trace" level="trace" -->
>>> Â Â Â Â <appenders>
>>> Â Â Â Â Â Â Â Â <FastRollingFile name="DLA"
>>> Â Â Â Â Â Â Â Â Â Â Â Â fileName="/tmp/att/sync/log/dla.log"
>>> Â Â Â Â Â Â Â Â Â Â Â Â
>>> filePattern="/tmp/att/sync/log/dla.log.%i" append="true">
>>> Â Â Â Â Â Â Â Â Â Â Â Â <PatternLayout>
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
>>> <pattern>[%d][%-5p][%-15t][%-15c{1}]:%m%n</pattern>
>>> Â Â Â Â Â Â Â Â Â Â Â Â </PatternLayout>
>>> Â Â Â Â Â Â Â Â Â Â Â Â <Policies>
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â <SizeBasedTriggeringPolicy
>>> size="3 MB" />
>>> Â Â Â Â Â Â Â Â Â Â Â Â </Policies>
>>> Â Â Â Â Â Â Â Â Â Â Â Â <DefaultRolloverStrategy max="2" />
>>> Â Â Â Â Â Â Â Â </FastRollingFile>
>>> Â Â Â Â Â Â Â Â <FastRollingFile name="DEVICES"
>>> Â Â Â Â Â Â Â Â Â Â Â Â
>>> fileName="/tmp/att/sync/log/dla_devices.log"
>>> Â Â Â Â Â Â Â Â Â Â Â Â
>>> filePattern="/tmp/att/sync/log/dla_devices.log.%i" append="true">
>>> Â Â Â Â Â Â Â Â Â Â Â Â <PatternLayout>
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
>>> <pattern>[%d][%-5p][%-15t][%-15c{1}]:%m%n</pattern>
>>> Â Â Â Â Â Â Â Â Â Â Â Â </PatternLayout>
>>> Â Â Â Â Â Â Â Â Â Â Â Â <Policies>
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â <SizeBasedTriggeringPolicy
>>> size="3 MB" />
>>> Â Â Â Â Â Â Â Â Â Â Â Â </Policies>
>>> Â Â Â Â Â Â Â Â Â Â Â Â <DefaultRolloverStrategy max="1" />
>>> Â Â Â Â Â Â Â Â </FastRollingFile>
>>> Â Â Â Â Â Â Â Â <FastRollingFile name="VIDEO"
>>> Â Â Â Â Â Â Â Â Â Â Â Â
>>> fileName="/tmp/att/sync/log/dla_video.log"
>>> Â Â Â Â Â Â Â Â Â Â Â Â
>>> filePattern="/tmp/att/sync/log/dla_video.log.%i" append="true">
>>> Â Â Â Â Â Â Â Â Â Â Â Â <PatternLayout>
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
>>> <pattern>[%d][%-5p][%-15t][%-15c{1}]:%m%n</pattern>
>>> Â Â Â Â Â Â Â Â Â Â Â Â </PatternLayout>
>>> Â Â Â Â Â Â Â Â Â Â Â Â <Policies>
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â <SizeBasedTriggeringPolicy
>>> size="3 MB" />
>>> Â Â Â Â Â Â Â Â Â Â Â Â </Policies>
>>> Â Â Â Â Â Â Â Â Â Â Â Â <DefaultRolloverStrategy max="1" />
>>> Â Â Â Â Â Â Â Â </FastRollingFile>
>>> Â Â Â Â Â Â Â Â <Console name="CO" target="SYSTEM_OUT">
>>> Â Â Â Â Â Â Â Â Â Â Â Â <PatternLayout pattern="%d %-5p [%t]
>>> %C{2} (%F:%L) - %m%n" />
>>> Â Â Â Â Â Â Â Â </Console>
>>> Â Â Â Â </appenders>
>>> Â Â Â Â <loggers>
>>> Â Â Â Â Â Â Â Â <logger name="com.att.dlc.afm" additivity="false" >
>>> Â Â Â Â Â Â Â Â Â Â Â Â <appender-ref ref="DLA" />
>>> Â Â Â Â Â Â Â Â </logger>
>>> Â Â Â Â Â Â Â Â <logger name="com.att.dlc.devices"
>>> additivity="false" level="debug">
>>> Â Â Â Â Â Â Â Â Â Â Â Â <appender-ref ref="DEVICES" />
>>> Â Â Â Â Â Â Â Â </logger>
>>> Â Â Â Â Â Â Â Â <logger name="com.att.dlc.util.serialport"
>>> additivity="false" level="debug">
>>> Â Â Â Â Â Â Â Â Â Â Â Â <appender-ref ref="DEVICES" />
>>> Â Â Â Â Â Â Â Â </logger>
>>> Â Â Â Â Â Â Â Â <logger name="com.att.dlc.webcamserver"
>>> additivity="false" level="debug">
>>> Â Â Â Â Â Â Â Â Â Â Â Â <appender-ref ref="VIDEO" />
>>> Â Â Â Â Â Â Â Â </logger>
>>> Â Â Â Â Â Â Â Â <logger name="com.att.dlc.devices.cameras"
>>> additivity="false" level="debug">
>>> Â Â Â Â Â Â Â Â Â Â Â Â <appender-ref ref="VIDEO" />
>>> Â Â Â Â Â Â Â Â </logger>
>>> Â Â Â Â Â Â Â Â <root level="debug">
>>> Â Â Â Â Â Â Â Â Â Â Â Â <appender-ref ref="DLA" />
>>> Â Â Â Â Â Â Â Â </root>
>>> Â Â Â Â </loggers>
>>> </configuration>
>>>
>>> Curt Smith
>>> AT&T Digital Life
>>> DLC Software Development
>>> 404-499-7013
>>> (cell) 678-365-6508
>>>
>>>
>>>
>>
>>
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