Use hibernate second-level cache when loading card sets on initial page load. Room for improvement here by using a more production-ready cache provider, but the immediate need is to not crash the database server under crush load.

build.properties.example

@@ -21,3 +21,16 @@ hibernate.password=CorrectHorseBatteryStaple
 # debugging information
 hibernate.sql.show=false
 hibernate.sql.format=false
+
+# second-level hibernate cache.
+# vastly reduces database load at expense of data potentially being stale.
+# use an in-memory cache provider. this is not suitable for long-term use, however I am using it for
+# my servers for the time being -- better than nothing
+#hibernate.cache.use_second_level_cache=true
+#hibernate.cache.use_query_cache=true
+#hibernate.cache.provider_class=org.hibernate.cache.HashtableCacheProvider
+
+# to turn it off, use these settings instead. you will hit the db a lot more often.
+hibernate.cache.use_second_level_cache=false
+hibernate.cache.use_query_cache=false
+hibernate.cache.provider_class=org.hibernate.cache.NoCacheProvider

src/main/filtered-resources/WEB-INF/classes/hibernate.cfg.xml

@@ -10,6 +10,10 @@
         <property name="hibernate.connection.username">${hibernate.username}</property>
         <property name="hibernate.connection.password">${hibernate.password}</property>
         <property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
+
+        <property name="hibernate.cache.use_second_level_cache">${hibernate.cache.use_second_level_cache}</property>
+        <property name="hibernate.cache.provider_class">${hibernate.cache.provider_class}</property>
+        <property name="hibernate.cache.use_query_cache">${hibernate.cache.use_query_cache}</property>
         
         <property name="show_sql">${hibernate.sql.show}</property>
         <property name="format_sql">${hibernate.sql.format}</property>

src/main/java/net/socialgamer/cah/db/PyxBlackCard.java

@@ -1,16 +1,16 @@
 /**
  * Copyright (c) 2012, Andy Janata
  * All rights reserved.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without modification, are permitted
  * provided that the following conditions are met:
- * 
+ *
  * * Redistributions of source code must retain the above copyright notice, this list of conditions
  *   and the following disclaimer.
  * * Redistributions in binary form must reproduce the above copyright notice, this list of
  *   conditions and the following disclaimer in the documentation and/or other materials provided
  *   with the distribution.
- * 
+ *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
@@ -23,6 +23,7 @@
 
 package net.socialgamer.cah.db;
 
+import javax.persistence.Cacheable;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.Id;
@@ -30,14 +31,19 @@ import javax.persistence.Table;
 
 import net.socialgamer.cah.data.BlackCard;
 
+import org.hibernate.annotations.Cache;
+import org.hibernate.annotations.CacheConcurrencyStrategy;
+
 
 /**
  * A Black Card. Cards are persisted in a database and loaded with Hibernate.
- * 
+ *
  * @author Andy Janata (ajanata@socialgamer.net)
  */
 @Entity
 @Table(name = "black_cards")
+@Cacheable
+@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
 public class PyxBlackCard extends BlackCard {
 
   @Id

src/main/java/net/socialgamer/cah/db/PyxCardSet.java

@@ -4,6 +4,7 @@ import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 
+import javax.persistence.Cacheable;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.Id;
@@ -16,12 +17,16 @@ import net.socialgamer.cah.Constants.CardSetData;
 import net.socialgamer.cah.data.CardSet;
 
 import org.hibernate.Session;
+import org.hibernate.annotations.Cache;
+import org.hibernate.annotations.CacheConcurrencyStrategy;
 import org.hibernate.annotations.LazyCollection;
 import org.hibernate.annotations.LazyCollectionOption;
 
 
 @Entity
 @Table(name = "card_set")
+@Cacheable
+@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
 public class PyxCardSet extends CardSet {
 
   @Id
@@ -40,6 +45,7 @@ public class PyxCardSet extends CardSet {
       joinColumns = { @JoinColumn(name = "card_set_id") },
       inverseJoinColumns = { @JoinColumn(name = "black_card_id") })
   @LazyCollection(LazyCollectionOption.TRUE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private final Set<PyxBlackCard> blackCards;
 
   @ManyToMany
@@ -48,6 +54,7 @@ public class PyxCardSet extends CardSet {
       joinColumns = { @JoinColumn(name = "card_set_id") },
       inverseJoinColumns = { @JoinColumn(name = "white_card_id") })
   @LazyCollection(LazyCollectionOption.TRUE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private final Set<PyxWhiteCard> whiteCards;
 
   public PyxCardSet() {
@@ -124,11 +131,11 @@ public class PyxCardSet extends CardSet {
     final Map<CardSetData, Object> cardSetData = getCommonClientMetadata();
     final Number blackCount = (Number) hibernateSession
         .createQuery("select count(*) from PyxCardSet cs join cs.blackCards where cs.id = :id")
-        .setParameter("id", id).uniqueResult();
+        .setParameter("id", id).setCacheable(true).uniqueResult();
     cardSetData.put(CardSetData.BLACK_CARDS_IN_DECK, blackCount);
     final Number whiteCount = (Number) hibernateSession
         .createQuery("select count(*) from PyxCardSet cs join cs.whiteCards where cs.id = :id")
-        .setParameter("id", id).uniqueResult();
+        .setParameter("id", id).setCacheable(true).uniqueResult();
     cardSetData.put(CardSetData.WHITE_CARDS_IN_DECK, whiteCount);
     return cardSetData;
   }

src/main/java/net/socialgamer/cah/db/PyxWhiteCard.java

@@ -1,16 +1,16 @@
 /**
  * Copyright (c) 2012, Andy Janata
  * All rights reserved.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without modification, are permitted
  * provided that the following conditions are met:
- * 
+ *
  * * Redistributions of source code must retain the above copyright notice, this list of conditions
  *   and the following disclaimer.
  * * Redistributions in binary form must reproduce the above copyright notice, this list of
  *   conditions and the following disclaimer in the documentation and/or other materials provided
  *   with the distribution.
- * 
+ *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
@@ -23,6 +23,7 @@
 
 package net.socialgamer.cah.db;
 
+import javax.persistence.Cacheable;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.Id;
@@ -30,14 +31,19 @@ import javax.persistence.Table;
 
 import net.socialgamer.cah.data.WhiteCard;
 
+import org.hibernate.annotations.Cache;
+import org.hibernate.annotations.CacheConcurrencyStrategy;
+
 
 /**
  * A white Card. Cards are persisted in a database and loaded with Hibernate.
- * 
+ *
  * @author Andy Janata (ajanata@socialgamer.net)
  */
 @Entity
 @Table(name = "white_cards")
+@Cacheable
+@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
 public class PyxWhiteCard extends WhiteCard {
 
   @Id

src/main/java/net/socialgamer/cah/handlers/FirstLoadHandler.java

@@ -98,6 +98,7 @@ public class FirstLoadHandler extends Handler {
       final List<PyxCardSet> cardSets = hibernateSession
           .createQuery(PyxCardSet.getCardsetQuery(includeInactiveCardsetsProvider.get()))
           .setReadOnly(true)
+          .setCacheable(true)
           .list();
       final List<Map<CardSetData, Object>> cardSetsData =
           new ArrayList<Map<CardSetData, Object>>(cardSets.size());