Provide faster alternative to SimpleDataFormat ---------------------------------------------- Key: LOGMGR-157 URL: https://issues.jboss.org/browse/LOGMGR-157 Project: JBoss Log Manager Issue Type: Enhancement Components: core Affects Versions: 2.0.6.Final Reporter: Koen Janssens Attachments: DateFormatPerformance.java Whenever a data or timestamp is included in the logging pattern, SimpleDataFormat is used for formatting. Even with one instance per thread, it is still a heavy beast. Other logging libraries (like the 15 year old log4j) have 'fast tracks' for known formats such as ISO 8601. These implementations are faster and generate less memory garbage. During profiling, i discovered that simpledateformat is doing a lot of stuff while printing a date: at java.lang.Thread.run(Thread.java:748) at org.jboss.logmanager.handlers.AsyncHandler$AsyncTask.run(AsyncHandler.java:196) at org.jboss.logmanager.ExtHandler.publish(ExtHandler.java:76) at org.jboss.logmanager.handlers.WriterHandler.doPublish(WriterHandler.java:46) at org.jboss.logmanager.ExtFormatter.format(ExtFormatter.java:32) at org.jboss.logmanager.formatters.MultistepFormatter.format(MultistepFormatter.java:83) at org.jboss.logmanager.formatters.Formatters$JustifyingFormatStep.render(Formatters.java:224) at org.jboss.logmanager.formatters.Formatters$5.renderRaw(Formatters.java:389) at java.text.DateFormat.format(DateFormat.java:345) at java.text.SimpleDateFormat.format(SimpleDateFormat.java:936) at java.text.SimpleDateFormat.format(SimpleDateFormat.java:966) at java.text.SimpleDateFormat.subFormat(SimpleDateFormat.java:1125) at java.util.Calendar.getDisplayName(Calendar.java:2110) at java.text.DateFormatSymbols.getInstance(DateFormatSymbols.java:340) at java.text.DateFormatSymbols.getProviderInstance(DateFormatSymbols.java:364) at sun.util.locale.provider.DateFormatSymbolsProviderImpl.getInstance(DateFormatSymbolsProviderImpl.java:85) at java.text.DateFormatSymbols.<init>(DateFormatSymbols.java:145) at java.text.DateFormatSymbols.initializeData(DateFormatSymbols.java:710) at sun.util.resources.LocaleData.getDateFormatData(LocaleData.java:127) at sun.util.resources.LocaleData.getBundle(LocaleData.java:163) at java.security.AccessController.doPrivileged(Native Method) at sun.util.resources.LocaleData$1.run(LocaleData.java:163) at sun.util.resources.LocaleData$1.run(LocaleData.java:167) at java.util.ResourceBundle.getBundle(ResourceBundle.java:890) at java.util.ResourceBundle.getBundleImpl(ResourceBundle.java:1348) at java.util.ResourceBundle.checkList(ResourceBundle.java:1400) at java.util.Collections$UnmodifiableCollection.isEmpty(Collections.java:1031) at java.util.AbstractCollection.isEmpty(AbstractCollection.java:86) I have attached a small comparision between simpledateformat performance and log4j ISO formatting performance. It roughly a factor 10 'faster'