Small wiki pages take forever to render - apparent JSPWiki 2.8.3/2.8.4 performance problem

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 6.1.0 CE RC1
• Fix Version/s: 6.1.X EE, 6.2.0 CE M5
• Component/s: Collaboration, Collaboration > Wiki, Operations > Performance
• Labels:
  • QA-R
• Environment: Mac OS X 10.6.6 - java full version "1.6.0_22-b04-307" - Liferay trunk rev 74794 - JSPWiki 2.8.3 or 2.8.4
• Epic/Theme:
  • Platform
• Fix Priority: 3
• Liferay Contributor's Agreement:
  Accept
• Similar Issues: Show 5 results ; ;

  LPS-24954	Wiki attachments should be easily linked to (like in JSPWiki)
  LPS-30552	Performance Improvement on Manage Page Dialog
  LPS-28257	Interwiki-Links are not working using JSPWiki-Engine
  LPS-29406	Images in blog, wiki or message board render slowly in Internet explorer 7 and 8.
  LPS-14131	Performance of Wiki, Document Library and Asset Publisher very slow

When rendering a short but non-trivial wiki page, Liferay appears to hang for minutes at a time. In some cases, the rendering finally completes normally after a long time (at 100% cpu), or sometimes renders a CreoleError and the wiki markup is rendered "raw" (i.e. not parsed and properly turned into formatted HTML).

During the rendering, generating many stack trace dumps reveals that the JSPWiki CreoleFilter is taking an abnormally long time to render relatively simple pages that contain many links (using [[ ]]) and other link constructs. Removing them and leaving only the basic wiki markup (e.g. headers, bold/italic, etc) makes it render at a "normal" speed (i.e. very fast).

Attached is an example text file of wiki markup taken from a public Liferay wiki page. The relevant stack trace bits are below. Note the "**" next to the replaceImageArea method. This method appears to be in some kind of tight parsing loop using Java regex libraries. The source to this method can be seen at http://svn.apache.org/repos/asf/incubator/jspwiki/branches/JSPWIKI_2_8_BRANCH/src/com/ecyrd/jspwiki/parser/CreoleToJSPWikiTranslator.java
(there is also anonymous SVN access to get the full source for debugging purposes).

java.util.regex.Pattern$Slice.match(Pattern.java:3482)
java.util.regex.Pattern$GroupTail.match(Pattern.java:4227)
java.util.regex.Pattern$Curly.match1(Pattern.java:3797)
java.util.regex.Pattern$Curly.match(Pattern.java:3746)
java.util.regex.Pattern$GroupHead.match(Pattern.java:4168)
java.util.regex.Pattern$Slice.match(Pattern.java:3482)
java.util.regex.Pattern$Start.match(Pattern.java:3055)
java.util.regex.Matcher.search(Matcher.java:1105)
java.util.regex.Matcher.find(Matcher.java:535)

• • com.ecyrd.jspwiki.parser.CreoleToJSPWikiTranslator.replaceImageArea(CreoleToJSPWikiTranslator.java:430)
    com.ecyrd.jspwiki.parser.CreoleToJSPWikiTranslator.translate(CreoleToJSPWikiTranslator.java:251)
    com.ecyrd.jspwiki.filters.CreoleFilter.preTranslate(CreoleFilter.java:93)
    com.liferay.portlet.wiki.engines.jspwiki.filters.CreoleFilter.preTranslate(CreoleFilter.java:63)
    com.ecyrd.jspwiki.filters.FilterManager.doPreTranslateFiltering(FilterManager.java:326)
    com.ecyrd.jspwiki.WikiEngine.textToHTML(WikiEngine.java:1514)
    com.liferay.portlet.wiki.engines.jspwiki.JSPWikiEngine.convert(JSPWikiEngine.java:158)
    com.liferay.portlet.wiki.engines.jspwiki.JSPWikiEngine.convert(JSPWikiEngine.java:65)
    com.liferay.portlet.wiki.util.WikiUtil._convert(WikiUtil.java:412)
    com.liferay.portlet.wiki.util.WikiUtil.convert(WikiUtil.java:78)
    com.liferay.portlet.wiki.util.WikiUtil.diffHtml(WikiUtil.java:91)
    com.liferay.portlet.wiki.service.impl.WikiPageLocalServiceImpl.notifySubscribers(WikiPageLocalServiceImpl.java:1498)
    com.liferay.portlet.wiki.service.impl.WikiPageLocalServiceImpl.updateStatus(WikiPageLocalServiceImpl.java:1324)
    com.liferay.portlet.wiki.service.impl.WikiPageLocalServiceImpl.updateStatus(WikiPageLocalServiceImpl.java:1245)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    java.lang.reflect.Method.invoke(Method.java:597)
    org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)

[Jelmer Kuperus]

This issue is being addressed as part of the 100 PaperCuts program. Please see http://liferay.com/community/100-papercuts

Got it to reproduce on liferay trunk revision 77082

[Jelmer Kuperus]

Full thread dump, same thread in 5 consecutive thread dumps

[Jelmer Kuperus]

Main class that reproduces the issue in jsp wiki outside of liferay

[Jelmer Kuperus]

Created a bug in jspwiki's issue tracker and added a patch that fixes the issue to it

https://issues.apache.org/jira/browse/JSPWIKI-688

[Jelmer Kuperus]

I attached a patch for the 2.8 version of jsp wiki that Liferay uses, and attached a binary jar which has the patch applied.

There was no easy way to work around this in Liferay itself short of copying the entire CreoleToJSPWikiTranslator class to liferay and using that

[Miguel Pastor]

Hi,

In 6.1.X we are using our current Creole parser implementation (based on ANTLR grammar instead using regular expressions). We are not using the JSPWiki creole parser.

We could introduce this patch as a backport for older version of Liferay.

Cheers,

Migue

[James Falkner]

Re-tested on 6.1 GA1 - the issue no longer exists - it renders very fast now.

[James Falkner]

Also verified Jelmer's fix on 6.0.6.

[James Falkner]

And finally.. the fix is also in the more recent versions of JSPWiki, according to https://issues.apache.org/jira/browse/JSPWIKI-688 so a potential patch for Liferay 6.0 is to upgrade to JSPWiki 2.8.5 or 3.0.

[Sophia Zhang]

PASSED Manual Testing using the following steps:

Add short but non-trivial wiki page, then try to save to check if it render slowly or not.

Fixed on:
Tomcat 7 + MySQL 5. Portal 6.1.x EE GIT ID: b5e90c191c6e804823839080898babcff418e65e.
Tomcat 7 + MySQL 5. Portal 6.2.x GIT ID: ff3ae0860119f0a06bb05a0b27e5165c5673d387.

Wiki page renders very fast. No above problems from the description.