Terracotta Discussion Forums (LEGACY READ-ONLY ARCHIVE)

Hello,

I'm using Ehcache (2.4.2) clustered with Terracota (3.5.1). I'm using express installation (no DSO). Ocassionally I'm receiving the following exception when reading value from cache:

Code:

net.sf.ehcache.CacheException: java.lang.ClassNotFoundException: boolean
         at org.terracotta.modules.ehcache.store.ValueModeHandlerSerialization.getRealKeyObject(ValueModeHandlerSerialization.java:128)
         at org.terracotta.modules.ehcache.store.ValueModeHandlerSoftLockAwareSerialization.getRealKeyObject(ValueModeHandlerSoftLockAwareSerialization.java:68)
         at org.terracotta.modules.ehcache.store.ClusteredStoreBackendImpl$TDCWithEvents.onExpiry(ClusteredStoreBackendImpl.java:217)
         at org.terracotta.cache.TerracottaDistributedCache.expire(TerracottaDistributedCache.java:427)
         at org.terracotta.cache.TerracottaDistributedCache.getNonExpiredEntry(TerracottaDistributedCache.java:240)
         at org.terracotta.cache.TerracottaDistributedCache.getNonExpiredEntryCoherent(TerracottaDistributedCache.java:152)
         at org.terracotta.cache.TerracottaDistributedCache.getTimestampedValueQuiet(TerracottaDistributedCache.java:198)
         at org.terracotta.modules.ehcache.store.ClusteredStoreBackendImpl.getTimestampedValueQuiet(ClusteredStoreBackendImpl.java:70)
         at org.terracotta.modules.ehcache.store.backend.StrictBackend.get(StrictBackend.java:48)
         at org.terracotta.modules.ehcache.store.ClusteredStore.doGet(ClusteredStore.java:360)
         at org.terracotta.modules.ehcache.store.ClusteredStore.getQuiet(ClusteredStore.java:351)
         at net.sf.ehcache.Cache.searchInStoreWithoutStats(Cache.java:1925)
         at net.sf.ehcache.Cache.getQuiet(Cache.java:1788)
         at net.sf.ehcache.constructs.blocking.BlockingCache.get(BlockingCache.java:160)
         at net.sf.ehcache.constructs.blocking.SelfPopulatingCache.get(SelfPopulatingCache.java:68)
         at pl.sns.cache.ehcache.CacheUtils.get(CacheUtils.java:23)
         at pl.sns.cache.ehcache.CacheUtils.get(CacheUtils.java:16)
         at pl.sns.pap.service.ParameterSourceImpl.getParameter(ParameterSourceImpl.java:143)
         at $ParameterSource_1311e90c6ec.getParameter($ParameterSource_1311e90c6ec.java)
         at pl.sns.pap.client.components.RewardsEnabled.test(RewardsEnabled.java:17)
         at org.apache.tapestry5.corelib.base.AbstractConditional.beginRender(AbstractConditional.java:59)
         at org.apache.tapestry5.corelib.base.AbstractConditional$MethodAccess_beginRender_1311e90c7c1.invoke(AbstractConditional$MethodAccess_beginRender_1311e90c7c1.java)
         at org.apache.tapestry5.internal.transform.RenderPhaseMethodWorker$Invoker.invoke(RenderPhaseMethodWorker.java:117)
         at org.apache.tapestry5.internal.transform.RenderPhaseMethodWorker$RenderPhaseMethodAdvice.advise(RenderPhaseMethodWorker.java:86)
         at org.apache.tapestry5.internal.services.AbstractComponentMethodInvocation.proceed(AbstractComponentMethodInvocation.java:86)
         at org.apache.tapestry5.corelib.base.AbstractConditional.beginRender(AbstractConditional.java)
         at org.apache.tapestry5.internal.structure.ComponentPageElementImpl$BeginRenderPhase.invokeComponent(ComponentPageElementImpl.java:239)
         at org.apache.tapestry5.internal.structure.ComponentPageElementImpl$AbstractPhase.invoke(ComponentPageElementImpl.java:176)
         ... 122 more
 Caused by: java.lang.ClassNotFoundException: boolean
         at java.lang.ClassLoader.findClass(ClassLoader.java:358)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
         at org.terracotta.modules.ehcache.store.ThreadContextAwareClassLoader.loadClass(ThreadContextAwareClassLoader.java:34)
         at java.lang.Class.forName0(Native Method)
         at java.lang.Class.forName(Class.java:247)
         at org.terracotta.cache.serialization.DsoSerializationStrategy$OIS.resolveClass(DsoSerializationStrategy.java:111)
         at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1574)
         at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1495)
         at java.io.ObjectInputStream.readClass(ObjectInputStream.java:1461)
         at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1311)
         at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1946)
         at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1870)
         at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1752)
         at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1328)
         at java.io.ObjectInputStream.readObject(ObjectInputStream.java:350)
         at org.terracotta.cache.serialization.DsoSerializationStrategy2.deserializeStringKey(DsoSerializationStrategy2.java:73)
         at org.terracotta.modules.ehcache.store.ValueModeHandlerSerialization.getRealKeyObject(ValueModeHandlerSerialization.java:126)
         ... 149 more

Here's a configuration for the cache that causes problems:

Code:

<cache     
     name="parameters"     
     eternal="false"     
     maxElementsInMemory="100"     
     overflowToDisk="false"     
     timeToIdleSeconds="120"     
     timeToLiveSeconds="120"     
     statistics="true">    
     <terracotta>        
         <nonstop             
             enabled="false">        
         </nonstop>    
     </terracotta>
 </cache>

And here's my terracotta config

Code:

<con:tc-config xmlns:con="http://www.terracotta.org/config">
 <system xmlns:tc="http://www.terracotta.org/config">
 <configuration-model>development</configuration-model>
 </system>
 <clients xmlns:tc="http://www.terracotta.org/config">
 <logs>%(user.home)/terracotta/client-logs</logs>
 </clients>
 <servers xmlns:tc="http://www.terracotta.org/config">
 <server bind="0.0.0.0" host="192.168.0.22" name="192.168.0.22:9510">
 <data>/home/otomczak/terracotta/server-data</data>
 <logs>/home/otomczak/terracotta/server-logs</logs>
 <statistics>/home/otomczak/terracotta/server-statistics</statistics>
 <dso-port bind="0.0.0.0">9510</dso-port>
 <jmx-port bind="0.0.0.0">9520</jmx-port>
 <l2-group-port bind="0.0.0.0">9530</l2-group-port>
 <data-backup>
 /home/otomczak/tools/terracotta-3.5.1/bin/data-backup
 </data-backup>
 <index>/home/otomczak/terracotta/server-data/index</index>
 <dso>
 <client-reconnect-window>120</client-reconnect-window>
 <persistence>
 <mode>temporary-swap-only</mode>
 </persistence>
 <garbage-collection>
 <enabled>true</enabled>
 <verbose>false</verbose>
 <interval>3600</interval>
 </garbage-collection>
 </dso>
 </server>
 <mirror-groups>
 <mirror-group>
 <ha>
 <mode>networked-active-passive</mode>
 <networked-active-passive>
 <election-time>5</election-time>
 </networked-active-passive>
 </ha>
 <members>
 <member>192.168.0.22:9510</member>
 </members>
 </mirror-group>
 </mirror-groups>
 <ha>
 <mode>networked-active-passive</mode>
 <networked-active-passive>
 <election-time>5</election-time>
 </networked-active-passive>
 </ha>
 <update-check>
 <enabled>true</enabled>
 <period-days>7</period-days>
 </update-check>
 </servers>
 <application xmlns:tc="http://www.terracotta.org/config">
 <dso>
 <dso-reflection-enabled>true</dso-reflection-enabled>
 </dso>
 </application>
 </con:tc-config>

Any ideas or pointers what might be wrong with my configuration?

Thanks, Olaf

Unfortunately that looks like a bug. Is there any chance you are using a instance of boolean.class or java.lang.Boolean.TYPE as a key in this cache? That should work but unfortunately there is a bug with that in the current release and there isn't a workaround short of not using the primitive Class objects as direct cache keys

teck,

Thanks for the reply. I'm not using boolean as a cache key, I do however have a key class that contains final boolean field. Should I change it to java.lang.Boolean to make it work? Also does this problem apply to all primitive types?

Thanks, Olaf

Ok sorry Tim I misunderstood you.. You're talking about having boolean class object as a cache key and not a boolean. My key class looks like this:

Code:

  public static class Key implements Serializable {
 
         private static final long serialVersionUID = 1329312650381461450L;
         private final String      name;
         private final Class<?>    klass;
         private final boolean     collection;
 
         public Key(final String name, final Class<?> klass) {
 
             this(name, klass, false);
 
         }
 
         public Key(final String name, final Class<?> klass, final boolean collection) {
 
             super();
             this.name = name;
             this.klass = klass;
             this.collection = collection;
 
         }
 
         @Override
         public boolean equals(final Object obj) {
 
             if (obj == null) {
                 return false;
             }
             if (obj == this) {
                 return true;
             }
             if (!(obj instanceof Key)) {
                 return false;
             }
             final Key rhs = (Key) obj;
             return new EqualsBuilder().append(this.name, rhs.name).append(this.klass, rhs.klass).append(this.collection, rhs.collection).isEquals();
 
         }
 
         public Class<?> getKlass() {
 
             return this.klass;
         }
 
         public String getName() {
 
             return this.name;
         }
 
         @Override
         public int hashCode() {
 
             return new HashCodeBuilder().append(this.name).append(this.klass).append(this.collection).toHashCode();
 
         }
 
         public boolean isCollection() {
 
             return this.collection;
         }
 
     }

so I guess the problem occurs when we put boolean.class in 'klass' field. If this is a known bug then I'll just make sure to put Boolean.class there instead of boolean.class as a workaround.

Thanks, Olaf

Well I actually didn't ask the question correctly. What I really mean to ask is whether you had an instance of "boolean.class" and/or java.lang.Boolean.TYPE in the object graph of your cache key. From the example Key class posted it looks like that is at least a possibility. Avoiding the java.lang.Class instances that represent the java primitives (ie. Boolean.TYPE, Integer.TYPE, etc) should avoid this bug.

I don't know if swapping java.lang.Boolean.TYPE for java.lang.Boolean.class is a valid thing to do in your particular application. It will avoid the bug though

hope this helps

I entered this a bug for good measure

https://jira.terracotta.org/jira/browse/CDV-1589

Tim,

Indeed switching from boolean.class to Boolean.class when creating cache keys fixed the problem.

Thank you for your help,
Olaf