Marco Roeland created JSPWIKI-809:
-------------------------------------
Summary: PageCache has hardcoded limit of 1000 and doesn't fail
gracefully
Key: JSPWIKI-809
URL: https://issues.apache.org/jira/browse/JSPWIKI-809
Project: JSPWiki
Issue Type: Bug
Components: Core & storage, Unit Testing
Affects Versions: 2.10
Environment: Linux, java 1.7.0_45
Reporter: Marco Roeland
Priority: Minor
Summary: if you have "too many" (1000) pages in your Wiki at least
in Tomcat 7.0.47 the JSPWiki application fails and stops. This is
also reproducible in the unit tests, although there it is not noticed
normally at the moment because exactly the (working) boundary condition of 1000
is used.
The default for caching is "jspwiki.usePageCache = true". Since
2.10.0-svn-45 a new or at least changed CachingProvider is used.
It seems that in
jspwiki-war/src/main/java/org/apache/wiki/providers/CachingProvider.java
the default "public static final int DEFAULT_CACHECAPACITY = 1000; // Good
most wikis"
is always used, even if lower or higher values are used in ehcache.xml. Or
perhaps
the default ehcache.xml is in the wrong location to be used.
Steps to reproduce (version 2.10.0-svn-60 is used):
mvn -e test -Dtest=MassiveRepositoryTest -DfailIfNoTests=false
The "-DfailIfNoTests=false" is necessary in this case because otherwise we get
a test failure for jspwiki-pages-de. Possibly a bug in the test setup but
otherwise uninteresting.
The test succeeds.
Now edit
jspwiki-war/src/test/java/org/apache/wiki/stress/MassiveRepositoryTest.java
and on line 78 edit the line "int numPages = 1000;" and set numPages to a
value of 1001.
Rerun the test which now fails.
-------------------------------------------------------
T E S T S
-------------------------------------------------------
Running org.apache.wiki.stress.MassiveRepositoryTest
Creating 1001 pages
.....................................................................................................
Took 0:00:08.858, which is 113.00519304583428 adds/second
Checking in 1000 revisions
....................................................................................................
Took 0:00:06.360, which is 157.2327044025157 adds/second
Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 16.262 sec <<<
FAILURE! - in org.apache.wiki.stress.MassiveRepositoryTest
testMassiveRepository1(org.apache.wiki.stress.MassiveRepositoryTest) Time
elapsed: 16.198 sec <<< FAILURE!
junit.framework.AssertionFailedError: Right number of pages expected:<1001> but
was:<1000>
at junit.framework.Assert.fail(Assert.java:57)
at junit.framework.Assert.failNotEquals(Assert.java:329)
at junit.framework.Assert.assertEquals(Assert.java:78)
at junit.framework.Assert.assertEquals(Assert.java:234)
at junit.framework.TestCase.assertEquals(TestCase.java:401)
at
org.apache.wiki.stress.MassiveRepositoryTest.testMassiveRepository1(MassiveRepositoryTest.java:134)
Results :
Failed tests:
MassiveRepositoryTest.testMassiveRepository1:134 Right number of pages
expected:<1001> but was:<1000>
Tests run: 1, Failures: 1, Errors: 0, Skipped: 0
Perhaps the number 1000 was hardcoded in the test itself? Nope, if we change
numPages to 999 and rerun the test it succeeds.
Editing jspwiki-war/src/main/resources/ehcache.xml and changing all values of
1000 there to 100 still makes the test succeed with numPages set to 1000 and
fails with 1001.
If we however in
jspwiki-war/src/main/java/org/apache/wiki/providers/CachingProvider.java edit
line 92, shown below
public static final int DEFAULT_CACHECAPACITY = 1000; // Good most wikis
to 999, then the test succeeds with numPages at 999 (or lower) and fails with
numPages at 1000 (or higher).
Disabling the caching in
jspwiki-war/src/test/resources/jspwiki-vers-custom.properties by setting
jspwiki.usePageCache = false
makes the tests succeed, even beyond the limit at 1000. And this is also the
workaround if your Wiki has a large number of pages. In reality what exactly is
the limit is less clear. I have a single Tomcat instance with eight JSPWiki
applications and also eight separate pageDir repositories.
The larger ones "crash" (get stopped by Tomcat), but some crash even with
"only" 345 pages. The following is the only thing that gets logged in
catalina.out.
dec 29, 2013 10:00:53 AM org.apache.catalina.loader.WebappClassLoader loadClass
INFO: Illegal access: this web application instance has been stopped already.
Could not load net.sf.ehcache.util.ProductInfo. The eventual following stack
trace is caused by an error thrown for debugging purposes as well as to attempt
to terminate the thread which caused the illegal access, and has no functional
impact.
java.lang.IllegalStateException
at
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1588)
at
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
at
net.sf.ehcache.util.UpdateChecker.buildParamsString(UpdateChecker.java:133)
at
net.sf.ehcache.util.UpdateChecker.buildUpdateCheckUrl(UpdateChecker.java:123)
at net.sf.ehcache.util.UpdateChecker.doCheck(UpdateChecker.java:68)
at
net.sf.ehcache.util.UpdateChecker.checkForUpdate(UpdateChecker.java:60)
at net.sf.ehcache.util.UpdateChecker.run(UpdateChecker.java:51)
at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)
These same repositories had no caching problems with version 2.10.0-svn-15.
As an easy workaround exists (disabling cache) this is in my very humble
opinion no showstopper. Perhaps the fact a limit exists and especially that the
failure if you happen to stumble beyond isn't very clearly reported as an error
message, could be documented somewhere.
Also it might be nice to be able to configure the limit as a property. This
doesn't seem to be possible at the moment?
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