StackTraceInfo Class are initialised multiple times on stack trace logging

grep -A 50 http-nio-8080-exec-243 jira_threads.20161025-133* | grep -e 'com.atlassian.logging.log4j.FilteredPatternLayout.getThrowableStrRep' -e 'org.apache.log4j.WriterAppender.subAppend' -e 'java.lang.Thread.State' -e 'org.apache.log4j.Category.callAppenders' -e 'org.apache.logging.log4j.core.util.Loader.initializeClass'

jira_threads.20161025-133119.txt-   java.lang.Thread.State: RUNNABLE
jira_threads.20161025-133119.txt-	at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:310)
jira_threads.20161025-133119.txt-	at org.apache.log4j.Category.callAppenders(Category.java:206)

jira_threads.20161025-133131.txt-   java.lang.Thread.State: RUNNABLE
jira_threads.20161025-133131.txt-	at org.apache.logging.log4j.core.util.Loader.initializeClass(Loader.java:66)
jira_threads.20161025-133131.txt-	at com.atlassian.logging.log4j.FilteredPatternLayout.getThrowableStrRep(FilteredPatternLayout.java:359)
jira_threads.20161025-133131.txt-	at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:310)
jira_threads.20161025-133131.txt-	at org.apache.log4j.Category.callAppenders(Category.java:206)

jira_threads.20161025-133142.txt-   java.lang.Thread.State: RUNNABLE
jira_threads.20161025-133142.txt-	at org.apache.logging.log4j.core.util.Loader.initializeClass(Loader.java:66)
jira_threads.20161025-133142.txt-	at com.atlassian.logging.log4j.FilteredPatternLayout.getThrowableStrRep(FilteredPatternLayout.java:359)
jira_threads.20161025-133142.txt-	at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:310)
jira_threads.20161025-133142.txt-	at org.apache.log4j.Category.callAppenders(Category.java:206)

jira_threads.20161025-133153.txt-   java.lang.Thread.State: BLOCKED (on object monitor)
jira_threads.20161025-133153.txt-	at org.apache.log4j.Category.callAppenders(Category.java:204)

jira_threads.20161025-133204.txt-   java.lang.Thread.State: RUNNABLE
jira_threads.20161025-133204.txt-	at com.atlassian.logging.log4j.FilteredPatternLayout.getThrowableStrRep(FilteredPatternLayout.java:359)
jira_threads.20161025-133204.txt-	at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:310)
jira_threads.20161025-133204.txt-	at org.apache.log4j.Category.callAppenders(Category.java:206)

jira_threads.20161025-133215.txt-   java.lang.Thread.State: BLOCKED (on object monitor)
jira_threads.20161025-133215.txt-	at org.apache.log4j.Category.callAppenders(Category.java:204)

"http-nio-8080-exec-243 uri:/secure/admin/views/issuefields/screens/viewfieldscreens.jsp username:" #25366 daemon prio=5 tid=0x00007f41b8055800 nid=0x293d runnable [0x00007f3ec4d7c000]
  java.lang.Thread.State: RUNNABLE
      at java.util.zip.ZipFile.getEntry(Native Method)
      at java.util.zip.ZipFile.getEntry(ZipFile.java:310)
      - locked <0x00000007b5902e30> (a java.util.jar.JarFile)
      at java.util.jar.JarFile.getEntry(JarFile.java:240)
      at java.util.jar.JarFile.getJarEntry(JarFile.java:223)
      at org.apache.catalina.webresources.JarResourceSet.getArchiveEntry(JarResourceSet.java:120)
      at org.apache.catalina.webresources.AbstractArchiveResourceSet.getResource(AbstractArchiveResourceSet.java:260)
      at org.apache.catalina.webresources.StandardRoot.getResourceInternal(StandardRoot.java:281)
      at org.apache.catalina.webresources.Cache.getResource(Cache.java:63)
      at org.apache.catalina.webresources.StandardRoot.getResource(StandardRoot.java:216)
      at org.apache.catalina.webresources.StandardRoot.getClassLoaderResource(StandardRoot.java:225)
      at org.apache.catalina.loader.WebappClassLoaderBase.findResourceInternal(WebappClassLoaderBase.java:2569)
      at org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2406)
      at org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:831)
      at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1274)
      - locked <0x0000000401a8d810> (a org.apache.catalina.loader.WebappClassLoader)
      at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1139)
      at java.lang.Class.forName0(Native Method)
      at java.lang.Class.forName(Class.java:348)
      at org.apache.logging.log4j.core.util.Loader.initializeClass(Loader.java:66)
      at org.apache.logging.log4j.core.impl.ThrowableProxy.loadClass(ThrowableProxy.java:501)
      at org.apache.logging.log4j.core.impl.ThrowableProxy.toExtendedStackTrace(ThrowableProxy.java:629)
      at org.apache.logging.log4j.core.impl.ThrowableProxy.<init>(ThrowableProxy.java:111)
      at com.atlassian.logging.log4j.StackTraceInfo.buildPackagingRepresentation(StackTraceInfo.java:145)
      at com.atlassian.logging.log4j.StackTraceInfo.buildThrowableStrRep(StackTraceInfo.java:106)
      at com.atlassian.logging.log4j.StackTraceInfo.<init>(StackTraceInfo.java:43)
      at com.atlassian.logging.log4j.FilteredPatternLayout.getThrowableStrRep(FilteredPatternLayout.java:359)
      at com.atlassian.logging.log4j.FilteredPatternLayout.formatStackTrace(FilteredPatternLayout.java:336)
      at com.atlassian.logging.log4j.FilteredPatternLayout.format(FilteredPatternLayout.java:330)
      at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:310)
      at org.apache.log4j.RollingFileAppender.subAppend(RollingFileAppender.java:276)
      at org.apache.log4j.WriterAppender.append(WriterAppender.java:162)
      at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:251)
      - locked <0x0000000401138288> (a org.apache.log4j.RollingFileAppender)
      at com.atlassian.jira.logging.JiraHomeAppender.doAppend(JiraHomeAppender.java:206)
      at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:66)
      at org.apache.log4j.Category.callAppenders(Category.java:206)
      - locked <0x000000040113de30> (a org.apache.log4j.Logger)
      at org.apache.log4j.Category.forcedLog(Category.java:391)
      at org.apache.log4j.Category.log(Category.java:856)
      at org.slf4j.impl.Log4jLoggerAdapter.log(Log4jLoggerAdapter.java:601)
      at org.apache.commons.logging.impl.SLF4JLocationAwareLog.error(SLF4JLocationAwareLog.java:225)
      at webwork.util.ValueStack.findValue(ValueStack.java:532)
      at webwork.util.SimpleTest.test(SimpleTest.java:408)
      at webwork.util.ValueStack.test(ValueStack.java:157)
      at webwork.view.taglib.IfTag.doStartTag(IfTag.java:40)
      at jsp.secure.admin.views.issuefields.screens.viewfieldscreens_jsp._jspx_meth_ww_005fif_005f6(viewfieldscreens_jsp.java:2355)
      at jsp.secure.admin.views.issuefields.screens.viewfieldscreens_jsp._jspService(viewfieldscreens_jsp.java:281)
      at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
...