Performance bootleneck created by JTASessionContext#currentSession()

Theads dump contains a lot of threads that blocked by the hashtable.

"Thread-14" daemon prio=10 tid=0x00007f8bc059b000 nid=0x1657 waiting for monitor entry [0x00007f8b72ceb000]

java.lang.Thread.State: BLOCKED (on object monitor)
at java.util.Hashtable.get(Hashtable.java:458)

• waiting to lock <0x00000000b7be1788> (a java.util.Hashtable)
  at org.hibernate.context.internal.JTASessionContext.currentSession(JTASessionContext.java:106)
  at org.hibernate.internal.SessionFactoryImpl.getCurrentSession(SessionFactoryImpl.java:978)
  at com.naumen.core.server.flex.spi.ReloadableSessionFactoryBean$ReloadableSessionFactory.getCurrentSession(ReloadableSessionFactoryBean.java:233)
  at com.naumen.core.server.objectloader.DBKObjectLoader.get(DBKObjectLoader.java:51)