hibernate二级缓存不断清空自己

有一个Spring / Tomcat应用程序，我试图让ehcache作为Hibernate二级实体缓存工作 . 它已启用并处于活动状态 . 我可以在调试日志输出中看到缓存了多少实体 . 问题是，每隔几秒钟，缓存就会清空 . 我甚至固定了缓存（只是为了看看是否会改变行为）现在我看到了这个：

05-08-2017 16:05:21.550 [taskExecutor-12] {env=''} WARN  n.s.e.Cache: Data availability impacted:
****************************************************************************************
************************** removeAll called on a pinned cache **************************

05-08-2017 16:05:21.550 [taskExecutor-12] {env=''} WARN  n.s.e.Cache: Data availability impacted:
****************************************************************************************
************************** removeAll called on a pinned cache **************************

所以我认为这是问题所在 . 有什么想法会导致removeAll被隐式调用一遍又一遍吗？

ehcache.xml中

<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="ehcache.xsd"
    updateCheck="true"
    monitoring="autodetect"
    maxBytesLocalHeap="24G"
    dynamicConfig="true">

    <defaultCache eternal="true" maxBytesLocalHeap="1" /> <!-- not used, but required per ehcache configuration rules -->

    <!-- cache for foo -->
    <cache name="foo"
           maxBytesLocalHeap="8G"
           eternal="false"
           memoryStoreEvictionPolicy="LRU"
           timeToLiveSeconds="12000"
           transactionalMode="off">
        <pinning store="inCache" />
        <persistence strategy="none" />
    </cache>
</ehcache>

persistence.xml中

<properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
            <property name="hibernate.connection.driver_class" value="org.postgresql.Driver" />
            <property name="hibernate.show_sql" value="false" />
            <property name="hibernate.hbm2ddl.auto" value="update" />
            <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.ImprovedNamingStrategy" />
            <property name="hibernate.cache.provider_class" value="org.hibernate.cache.EhCacheProvider" />
            <property name="hibernate.cache.use_second_level_cache" value="true" />
            <property name="hibernate.cache.use_query_cache" value="false" />
            <property name="hibernate.generate_statistics" value="true" />
            <property name="hibernate.cache.use_structured_entries" value="true" />
            <property name="hibernate.cache.region.factory_class" value="org.hibernate.cache.ehcache.SingletonEhCacheRegionFactory" />
        </properties>

这些注释在实体模型类上：

@Cacheable
@Cache(region = "foo", usage = CacheConcurrencyStrategy.READ_WRITE)