Hibernate + EhCache = java.io.NotSerializableException

Question

Estoy haciendo la prueba de carga ahora. Después de aproximados 900 solicitudes tengo este error:

[ 03.08.10 11:49:00.465] [Store org.hibernate.cache.StandardQueryCache Spool Thread] ERROR net.sf.ehcache.store.DiskStore - org.hibernate.cache.StandardQueryCacheCache: Failed to write element to disk 'sql: select hotelfeatu0_.name as col_0_0_ from feature hotelfeatu0_ where hotelfeatu0_.class='org.company.domains.HotelFeatures' and hotelfeatu0_.lang=? and hotelfeatu0_.hotel_id=?; parameters: ; named parameters: {ht=100: 'Hotel', lng=en}'. Initial cause was org.company.domains.Hotel 
java.io.NotSerializableException: org.company.domains.Hotel 
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1156) 
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509) 
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474) 
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) 
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) 
    at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326) 
    at java.util.HashMap.writeObject(HashMap.java:1001) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
    at java.lang.reflect.Method.invoke(Method.java:597) 
    at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:945) 
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1461) 
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) 
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) 
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509) 
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474) 
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) 
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) 
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509) 
    at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:416) 
    at net.sf.ehcache.Element.writeObject(Element.java:729) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
    at java.lang.reflect.Method.invoke(Method.java:597) 
    at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:945) 
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1461) 
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) 
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) 
    at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326) 
    at net.sf.ehcache.util.MemoryEfficientByteArrayOutputStream.serialize(MemoryEfficientByteArrayOutputStream.java:75) 
    at net.sf.ehcache.store.DiskStore.serializeElement(DiskStore.java:781) 
    at net.sf.ehcache.store.DiskStore.writeElement(DiskStore.java:735) 
    at net.sf.ehcache.store.DiskStore.writeOrReplaceEntry(DiskStore.java:729) 
    at net.sf.ehcache.store.DiskStore.flushSpool(DiskStore.java:703) 
    at net.sf.ehcache.store.DiskStore.throwableSafeFlushSpoolIfRequired(DiskStore.java:671) 
    at net.sf.ehcache.store.DiskStore.spoolAndExpiryThreadMain(DiskStore.java:640) 
    at net.sf.ehcache.store.DiskStore.access$900(DiskStore.java:68) 
    at net.sf.ehcache.store.DiskStore$SpoolAndExpiryThread.run(DiskStore.java:1110) 

Aquí es mi ehcache.xml:

<?xml version="1.0" encoding="UTF-8"?> 
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="ehcache.xsd" updateCheck="false"> 

    <diskStore path="java.io.tmpdir/sweethome"/> 

    <defaultCache 
      maxElementsInMemory="10000" 
      eternal="false" 
      timeToIdleSeconds="120" 
      timeToLiveSeconds="120" 
      overflowToDisk="true" 
      maxElementsOnDisk="10000000" 
      diskPersistent="false" 
      diskExpiryThreadIntervalSeconds="120" 
      memoryStoreEvictionPolicy="LRU" 
    /> 

    <cache 
       name="org.hibernate.cache.StandardQueryCache" 
       maxElementsInMemory="5" 
       eternal="false" 
       timeToLiveSeconds="120" 
       overflowToDisk="true" 
    /> 

</ehcache> 

Hibernate config:

hibernate { 
    cache.use_second_level_cache=true 
    cache.use_query_cache=true 
    cache.provider_class='org.hibernate.cache.EhCacheProvider' 
    connection.useUnicode=true 
    connection.characterEncoding='UTF-8' 
    dialect = 'org.hibernate.dialect.MySQL5InnoDBDialect' 
} 

Answer 1

El registro me dice que esto sucede porque la consulta caché intenta escribir uno de sus objetos org.company.domains.Hotel en el disco. No es de extrañar que esto ocurra durante una prueba de carga, ya que solo permite 5 elementos en la memoria caché de consultas en la memoria antes de que intente vaciarla al disco.

O bien necesita hacer org.company.domains.Hotel implementar java.io.Serializable, o establecer overflowToDisk="false" para la caché de consultas.