From 31ee50d07da62eed26c47840cbb76ed99d3e8e80 Mon Sep 17 00:00:00 2001
From: Morten Svanaes <netroms@gmail.com>
Date: Sat, 8 Aug 2026 13:38:16 +0800
Subject: [PATCH 1/5] perf: NONSTRICT_READ_WRITE for the reference metadata
 bucket

Every cached region in DHIS2 uses READ_WRITE, whose access strategy holds
one ReentrantReadWriteLock PER REGION (not per key): every get takes the
region read lock and every putFromLoad takes the region WRITE lock, even
when it writes nothing (entities are unversioned, so an existing entry is
never overwritten from a load). Under concurrent load on option-heavy
metadata this serialises a whole region behind single-key work: measured
14-15% of ALL JVM wall samples parked in AbstractReadWriteAccess.

Switches the static reference bucket (Option*, PeriodType, DataElement,
Category*, OptionSet.options, Legend*, Indicator*, OrgUnit hierarchy;
30 files, 71 declarations) to NONSTRICT_READ_WRITE, which has no region
lock. Trade-off: a brief staleness window after a write, accepted for
reference metadata (sign-off: Morten, 2026-08-07). Period/RelativePeriods
stay READ_WRITE.

Measured on a tracker-import ramp: parked-in-region-lock 14.15% -> 0.05%,
p99 at 100 concurrent users 58.4s -> 20.7s as an isolated change.

AI Assisted
---
 .../main/java/org/hisp/dhis/category/Category.java |  6 +++---
 .../java/org/hisp/dhis/category/CategoryCombo.java |  4 ++--
 .../org/hisp/dhis/category/CategoryOption.java     | 10 +++++-----
 .../org/hisp/dhis/dataelement/DataElement.java     | 10 +++++-----
 .../org/hisp/dhis/indicator/IndicatorGroup.java    |  6 +++---
 .../org/hisp/dhis/indicator/IndicatorGroupSet.java |  4 ++--
 .../src/main/java/org/hisp/dhis/legend/Legend.java |  2 +-
 .../main/java/org/hisp/dhis/legend/LegendSet.java  |  2 +-
 .../main/java/org/hisp/dhis/option/OptionSet.java  |  2 +-
 .../hisp/dhis/category/hibernate/Category.hbm.xml  |  6 +++---
 .../category/hibernate/CategoryDimension.hbm.xml   |  4 ++--
 .../category/hibernate/CategoryOptionCombo.hbm.xml |  4 ++--
 .../category/hibernate/CategoryOptionGroup.hbm.xml |  6 +++---
 .../hibernate/CategoryOptionGroupSet.hbm.xml       |  4 ++--
 .../CategoryOptionGroupSetDimension.hbm.xml        |  4 ++--
 .../dataelement/hibernate/DataElementGroup.hbm.xml |  6 +++---
 .../hibernate/DataElementGroupSet.hbm.xml          |  4 ++--
 .../hibernate/DataElementGroupSetDimension.hbm.xml |  4 ++--
 .../hibernate/DataElementOperand.hbm.xml           |  2 +-
 .../dhis/indicator/hibernate/Indicator.hbm.xml     |  8 ++++----
 .../dhis/indicator/hibernate/IndicatorType.hbm.xml |  2 +-
 .../org/hisp/dhis/option/hibernate/Option.hbm.xml  |  2 +-
 .../hisp/dhis/option/hibernate/OptionGroup.hbm.xml |  4 ++--
 .../dhis/option/hibernate/OptionGroupSet.hbm.xml   |  4 ++--
 .../hibernate/OrganisationUnit.hbm.xml             | 14 +++++++-------
 .../hibernate/OrganisationUnitGroup.hbm.xml        |  6 +++---
 .../hibernate/OrganisationUnitGroupSet.hbm.xml     |  4 ++--
 .../OrganisationUnitGroupSetDimension.hbm.xml      |  4 ++--
 .../hibernate/OrganisationUnitLevel.hbm.xml        |  2 +-
 .../hisp/dhis/period/hibernate/PeriodType.hbm.xml  |  2 +-
 30 files changed, 71 insertions(+), 71 deletions(-)

diff --git a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/Category.java b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/Category.java
index f2dfa6a5ee3d..6ce3fcfb7a54 100644
--- a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/Category.java
+++ b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/Category.java
@@ -113,7 +113,7 @@
 @Entity
 @Table(name = "category")
 @Setter
-@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
 @JacksonXmlRootElement(localName = "category", namespace = DxfNamespaces.DXF_2_0)
 public class Category extends BaseMetadataObject
     implements DimensionalObject, SystemDefaultMetadataObject {
@@ -155,11 +155,11 @@ public class Category extends BaseMetadataObject
               name = "categoryoptionid",
               foreignKey = @ForeignKey(name = "fk_category_categoryoptionid")))
   @OrderColumn(name = "sort_order")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private List<CategoryOption> categoryOptions = new ArrayList<>();
 
   @ManyToMany(mappedBy = "categories", fetch = FetchType.LAZY)
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private Set<CategoryCombo> categoryCombos = new HashSet<>();
 
   @Embedded private TranslationProperty translations = new TranslationProperty();
diff --git a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/CategoryCombo.java b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/CategoryCombo.java
index 866137bf9979..8625aa8cc48d 100644
--- a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/CategoryCombo.java
+++ b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/CategoryCombo.java
@@ -124,11 +124,11 @@ public class CategoryCombo extends BaseMetadataObject
               foreignKey = @ForeignKey(name = "fk_categorycombo_categoryid")))
   @OrderColumn(name = "sort_order")
   @ListIndexBase(1)
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private List<Category> categories = new ArrayList<>();
 
   @OneToMany(fetch = FetchType.LAZY, mappedBy = "categoryCombo")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private Set<CategoryOptionCombo> optionCombos = new HashSet<>();
 
   @Column(name = "datadimensiontype", nullable = false)
diff --git a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/CategoryOption.java b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/CategoryOption.java
index 4f3666b1d426..22ed22343586 100644
--- a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/CategoryOption.java
+++ b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/category/CategoryOption.java
@@ -112,7 +112,7 @@
 @Entity
 @Table(name = "categoryoption")
 @Setter
-@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
 @JacksonXmlRootElement(localName = "categoryOption", namespace = DXF_2_0)
 public class CategoryOption extends BaseMetadataObject
     implements DimensionalItemObject, SystemDefaultMetadataObject, Serializable {
@@ -159,21 +159,21 @@ public class CategoryOption extends BaseMetadataObject
       name = "categoryoption_organisationunits",
       joinColumns = @JoinColumn(name = "categoryoptionid"),
       inverseJoinColumns = @JoinColumn(name = "organisationunitid"))
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   @BatchSize(size = 100)
   private Set<OrganisationUnit> organisationUnits = new HashSet<>();
 
   @ManyToMany(mappedBy = "categoryOptions")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   @BatchSize(size = 100)
   private Set<Category> categories = new HashSet<>();
 
   @ManyToMany(mappedBy = "categoryOptions")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private Set<CategoryOptionCombo> categoryOptionCombos = new HashSet<>();
 
   @ManyToMany(mappedBy = "members")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private Set<CategoryOptionGroup> groups = new HashSet<>();
 
   @Type(type = "jsbObjectSharing")
diff --git a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/dataelement/DataElement.java b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/dataelement/DataElement.java
index 9ec89f1285b2..f2625eac450c 100644
--- a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/dataelement/DataElement.java
+++ b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/dataelement/DataElement.java
@@ -132,7 +132,7 @@
 @Entity
 @Table(name = "dataelement")
 @Cacheable
-@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
 @JacksonXmlRootElement(localName = "dataElement", namespace = DxfNamespaces.DXF_2_0)
 public class DataElement extends BaseMetadataObject
     implements DimensionalItemObject,
@@ -213,12 +213,12 @@ public class DataElement extends BaseMetadataObject
 
   /** The data element groups which this data element is a member of. */
   @ManyToMany(mappedBy = "members")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private Set<DataElementGroup> groups = new HashSet<>();
 
   /** The data sets which this data element is a member of. */
   @OneToMany(mappedBy = "dataElement")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private Set<DataSetElement> dataSetElements = new HashSet<>();
 
   /** The lower organisation unit levels for aggregation. */
@@ -229,7 +229,7 @@ public class DataElement extends BaseMetadataObject
       foreignKey = @ForeignKey(name = "fk_dataelementaggregationlevels_dataelementid"))
   @Column(name = "aggregationlevel")
   @OrderColumn(name = "sort_order")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private List<Integer> aggregationLevels = new ArrayList<>();
 
   /** Indicates whether to store zero data values. */
@@ -258,7 +258,7 @@ public class DataElement extends BaseMetadataObject
               name = "legendsetid",
               foreignKey = @ForeignKey(name = "fk_dataelement_legendsetid")))
   @OrderColumn(name = "sort_order")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private List<LegendSet> legendSets = new ArrayList<>();
 
   @AuditAttribute
diff --git a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroup.java b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroup.java
index 55f8b0ccc916..0f78ce47b461 100644
--- a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroup.java
+++ b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroup.java
@@ -93,7 +93,7 @@
 @Setter
 @Entity
 @Table(name = "indicatorgroup")
-@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
 public class IndicatorGroup extends BaseMetadataObject
     implements IdentifiableObject, MetadataObject {
   @Id
@@ -123,7 +123,7 @@ public class IndicatorGroup extends BaseMetadataObject
           @JoinColumn(
               name = "indicatorid",
               foreignKey = @ForeignKey(name = "fk_indicatorgroup_indicatorid")))
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private Set<Indicator> members = new HashSet<>();
 
   @Type(type = "jsbAttributeValues")
@@ -135,7 +135,7 @@ public class IndicatorGroup extends BaseMetadataObject
   private Sharing sharing = new Sharing();
 
   @ManyToMany(mappedBy = "members", fetch = FetchType.LAZY)
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private Set<IndicatorGroupSet> groupSets = new HashSet<>();
 
   // -------------------------------------------------------------------------
diff --git a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroupSet.java b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroupSet.java
index c2e784eeb570..29fb410a825f 100644
--- a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroupSet.java
+++ b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroupSet.java
@@ -93,7 +93,7 @@
 @Setter
 @Entity
 @Table(name = "indicatorgroupset")
-@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
 public class IndicatorGroupSet extends BaseMetadataObject
     implements IdentifiableObject, MetadataObject {
 
@@ -134,7 +134,7 @@ public class IndicatorGroupSet extends BaseMetadataObject
               foreignKey = @ForeignKey(name = "fk_indicatorgroupset_indicatorgroupid")))
   @OrderColumn(name = "sort_order", nullable = false)
   @ListIndexBase(1)
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private List<IndicatorGroup> members = new ArrayList<>();
 
   // -------------------------------------------------------------------------
diff --git a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/legend/Legend.java b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/legend/Legend.java
index c4872212bf6e..d06a4a215d90 100644
--- a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/legend/Legend.java
+++ b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/legend/Legend.java
@@ -90,7 +90,7 @@
       @Index(name = "maplegend_endvalue", columnList = "endvalue")
     })
 @JacksonXmlRootElement(localName = "legend", namespace = DxfNamespaces.DXF_2_0)
-@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
 @Setter
 public class Legend implements IdentifiableObject, EmbeddedObject {
 
diff --git a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/legend/LegendSet.java b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/legend/LegendSet.java
index 7e5f105fc613..6a7b0918a0de 100644
--- a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/legend/LegendSet.java
+++ b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/legend/LegendSet.java
@@ -104,7 +104,7 @@ public class LegendSet extends BaseMetadataObject implements IdentifiableObject,
 
   @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
   @JoinColumn(name = "maplegendsetid")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private Set<Legend> legends = new HashSet<>();
 
   public LegendSet() {}
diff --git a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/option/OptionSet.java b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/option/OptionSet.java
index cf78c9c6369c..828d2909d789 100644
--- a/dhis-2/dhis-api/src/main/java/org/hisp/dhis/option/OptionSet.java
+++ b/dhis-2/dhis-api/src/main/java/org/hisp/dhis/option/OptionSet.java
@@ -127,7 +127,7 @@ public class OptionSet extends BaseMetadataObject implements IdentifiableObject,
   @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
   @JoinColumn(name = "optionsetid", foreignKey = @ForeignKey(name = "fk_optionset_optionid"))
   @OrderBy(value = "sortOrder ASC")
-  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+  @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   private List<Option> options = new ArrayList<>();
 
   @Type(type = "jsbAttributeValues")
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/Category.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/Category.hbm.xml
index 83cbc4ca5f4c..47cde3767e1b 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/Category.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/Category.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.category.Category" table="category">
 
-    <cache usage="read-write"/>
+    <cache usage="nonstrict-read-write"/>
 
     <id name="id" column="categoryid">
       <generator class="native"/>
@@ -30,7 +30,7 @@
               not-null="true"/>
 
     <list name="categoryOptions" table="categories_categoryoptions">
-      <cache usage="read-write"/>
+      <cache usage="nonstrict-read-write"/>
       <key column="categoryid"
            foreign-key="fk_categories_categoryoptions_categoryid"/>
       <list-index column="sort_order" base="1"/>
@@ -40,7 +40,7 @@
     </list>
 
     <set name="categoryCombos" table="categorycombos_categories" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="categoryid" foreign-key="fk_categorycombo_categoryid" />
       <many-to-many class="org.hisp.dhis.category.CategoryCombo" column="categorycomboid"
         foreign-key="fk_categorycombos_categories_categorycomboid" />
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryDimension.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryDimension.hbm.xml
index 34f17b542d98..ac15abaa5f82 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryDimension.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryDimension.hbm.xml
@@ -6,7 +6,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.category.CategoryDimension" table="categorydimension">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="categorydimensionid">
       <generator class="native" />
@@ -16,7 +16,7 @@
       foreign-key="fk_categorydimension_category" />
     
     <list name="items" table="categorydimension_items">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="categorydimensionid" foreign-key="fk_categorydimension_items_categorydimensionid" />
       <list-index column="sort_order" />
       <many-to-many class="org.hisp.dhis.category.CategoryOption" column="categoryoptionid"
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionCombo.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionCombo.hbm.xml
index bb4469cb51ad..fa5a8ec86e77 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionCombo.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionCombo.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.category.CategoryOptionCombo" table="categoryoptioncombo">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="categoryoptioncomboid">
       <generator class="native" />
@@ -20,7 +20,7 @@
     <property name="translations" type="jblTranslations"/>
 
     <set name="categoryOptions" table="categoryoptioncombos_categoryoptions">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="categoryoptioncomboid" foreign-key="fk_categoryoptioncombos_categoryoptions_categoryoptioncomboid" />
       <many-to-many class="org.hisp.dhis.category.CategoryOption" column="categoryoptionid"
         foreign-key="fk_categoryoptioncombo_categoryoptionid" />
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroup.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroup.hbm.xml
index 5a0aed492b96..dde1777d2fc7 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroup.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroup.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.category.CategoryOptionGroup" table="categoryoptiongroup">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="categoryoptiongroupid">
       <generator class="native" />
@@ -24,14 +24,14 @@
     <property name="translations" type="jblTranslations"/>
 
     <set name="members" table="categoryoptiongroupmembers">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="categoryoptiongroupid" foreign-key="fk_categoryoptiongroupmembers_categoryoptionid" />
       <many-to-many class="org.hisp.dhis.category.CategoryOption" column="categoryoptionid"
         foreign-key="fk_categoryoptiongroupmembers_categoryoptiongroupid" />
     </set>
 
     <set name="groupSets" table="categoryoptiongroupsetmembers" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="categoryoptiongroupid" />
       <many-to-many class="org.hisp.dhis.category.CategoryOptionGroupSet" column="categoryoptiongroupsetid" />
     </set>
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroupSet.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroupSet.hbm.xml
index 3c98531a8f9f..04dc7e8135c2 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroupSet.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroupSet.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.category.CategoryOptionGroupSet" table="categoryoptiongroupset">
 
-    <cache usage="read-write"/>
+    <cache usage="nonstrict-read-write"/>
 
     <id name="id" column="categoryoptiongroupsetid">
       <generator class="native"/>
@@ -26,7 +26,7 @@
     <property name="dataDimension" column="datadimension" not-null="true"/>
 
     <list name="members" table="categoryoptiongroupsetmembers">
-      <cache usage="read-write"/>
+      <cache usage="nonstrict-read-write"/>
       <key column="categoryoptiongroupsetid"
            foreign-key="fk_categoryoptiongroupsetmembers_categoryoptiongroupsetid"/>
       <list-index column="sort_order" base="1"/>
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroupSetDimension.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroupSetDimension.hbm.xml
index 76199b2b1845..1e62d273551f 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroupSetDimension.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/category/hibernate/CategoryOptionGroupSetDimension.hbm.xml
@@ -6,7 +6,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.category.CategoryOptionGroupSetDimension" table="categoryoptiongroupsetdimension">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="categoryoptiongroupsetdimensionid">
       <generator class="native" />
@@ -16,7 +16,7 @@
       foreign-key="fk_dimension_categoryoptiongroupsetid" />
     
     <list name="items" table="categoryoptiongroupsetdimension_items">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="categoryoptiongroupsetdimensionid" foreign-key="fk_dimension_items_categoryoptiongroupsetdimensionid" />
       <list-index column="sort_order" />
       <many-to-many class="org.hisp.dhis.category.CategoryOptionGroup" column="categoryoptiongroupid"
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroup.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroup.hbm.xml
index 96a1c3506f05..f054285320c7 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroup.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroup.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.dataelement.DataElementGroup" table="dataelementgroup">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="dataelementgroupid">
       <generator class="native" />
@@ -24,14 +24,14 @@
     <property name="translations" type="jblTranslations"/>
 
     <set name="members" table="dataelementgroupmembers">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="dataelementgroupid" foreign-key="fk_dataelementgroupmembers_dataelementgroupid" />
       <many-to-many class="org.hisp.dhis.dataelement.DataElement" column="dataelementid"
         foreign-key="fk_dataelementgroup_dataelementid" />
     </set>
 
     <set name="groupSets" table="dataelementgroupsetmembers" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="dataelementgroupid" />
       <many-to-many class="org.hisp.dhis.dataelement.DataElementGroupSet" column="dataelementgroupsetid" />
     </set>
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroupSet.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroupSet.hbm.xml
index 3a3bf8b9b264..6759f658ecd9 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroupSet.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroupSet.hbm.xml
@@ -9,7 +9,7 @@
   <class name="org.hisp.dhis.dataelement.DataElementGroupSet"
          table="dataelementgroupset">
 
-    <cache usage="read-write"/>
+    <cache usage="nonstrict-read-write"/>
 
     <id name="id" column="dataelementgroupsetid">
       <generator class="native"/>
@@ -31,7 +31,7 @@
     <property name="translations" type="jblTranslations"/>
 
     <list name="members" table="dataelementgroupsetmembers">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="dataelementgroupsetid" foreign-key="fk_dataelementgroupsetmembers_dataelementgroupsetid" />
       <list-index column="sort_order" base="1" />
       <many-to-many class="org.hisp.dhis.dataelement.DataElementGroup" column="dataelementgroupid"
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroupSetDimension.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroupSetDimension.hbm.xml
index 5ec41b9aad5d..b1a4047fbbe0 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroupSetDimension.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementGroupSetDimension.hbm.xml
@@ -6,7 +6,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.dataelement.DataElementGroupSetDimension" table="dataelementgroupsetdimension">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="dataelementgroupsetdimensionid">
       <generator class="native" />
@@ -16,7 +16,7 @@
       foreign-key="fk_dimension_dataelementgroupsetid" />
     
     <list name="items" table="dataelementgroupsetdimension_items">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="dataelementgroupsetdimensionid" foreign-key="fk_dimension_items_dataelementgroupsetdimensionid" />
       <list-index column="sort_order" />
       <many-to-many class="org.hisp.dhis.dataelement.DataElementGroup" column="dataelementgroupid"
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementOperand.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementOperand.hbm.xml
index df166643a1ab..bf5e66b20fbc 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementOperand.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/dataelement/hibernate/DataElementOperand.hbm.xml
@@ -6,7 +6,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.dataelement.DataElementOperand" table="dataelementoperand">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="dataelementoperandid">
       <generator class="native" />
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/indicator/hibernate/Indicator.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/indicator/hibernate/Indicator.hbm.xml
index 6e6bb75af306..a87a7fe615de 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/indicator/hibernate/Indicator.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/indicator/hibernate/Indicator.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.indicator.Indicator" table="indicator">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="indicatorid">
       <generator class="native" />
@@ -45,19 +45,19 @@
     <property name="style" type="jbObjectStyle" column="style" />
 
     <set name="groups" table="indicatorgroupmembers" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="indicatorid" />
       <many-to-many class="org.hisp.dhis.indicator.IndicatorGroup" column="indicatorgroupid" />
     </set>
 
     <set name="dataSets" table="datasetindicators" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="indicatorid" />
       <many-to-many class="org.hisp.dhis.dataset.DataSet" column="datasetid" />
     </set>
 
     <list name="legendSets" table="indicatorlegendsets">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="indicatorid" />
       <list-index column="sort_order" base="0" />
       <many-to-many class="org.hisp.dhis.legend.LegendSet" column="legendsetid" foreign-key="fk_indicator_legendsetid"></many-to-many>
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/indicator/hibernate/IndicatorType.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/indicator/hibernate/IndicatorType.hbm.xml
index 3f5dad21252f..8ea70707844e 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/indicator/hibernate/IndicatorType.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/indicator/hibernate/IndicatorType.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.indicator.IndicatorType" table="indicatortype">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="indicatortypeid">
       <generator class="native" />
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/Option.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/Option.hbm.xml
index 6c7ad80a99d2..31c0dc7cbf7f 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/Option.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/Option.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.option.Option" table="optionvalue">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="optionvalueid">
       <generator class="native" />
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/OptionGroup.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/OptionGroup.hbm.xml
index 0dbe22478cc5..86cf79fb13a2 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/OptionGroup.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/OptionGroup.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.option.OptionGroup" table="optiongroup">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="optiongroupid">
       <generator class="native" />
@@ -24,7 +24,7 @@
     <property name="translations" type="jblTranslations"/>
 
     <set name="members" table="optiongroupmembers" cascade="all">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="optiongroupid" foreign-key="fk_optiongroupmembers_optionid" />
       <many-to-many class="org.hisp.dhis.option.Option" column="optionid"
         foreign-key="fk_optiongroupmembers_optiongroupid" />
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/OptionGroupSet.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/OptionGroupSet.hbm.xml
index 5317ae76bc1f..81a83faba9f4 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/OptionGroupSet.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/option/hibernate/OptionGroupSet.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.option.OptionGroupSet" table="optiongroupset">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="optiongroupsetid">
       <generator class="native" />
@@ -24,7 +24,7 @@
     <property name="translations" type="jblTranslations"/>
 
     <list name="members" table="optiongroupsetmembers">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="optiongroupsetid" foreign-key="fk_optiongroupsetmembers_optiongroupsetid" />
       <list-index column="sort_order" base="1" />
       <many-to-many class="org.hisp.dhis.option.OptionGroup" column="optiongroupid" unique="true"
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnit.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnit.hbm.xml
index fc24b06c44c4..a3b96f1045fe 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnit.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnit.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.organisationunit.OrganisationUnit" table="organisationunit">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="organisationunitid">
       <generator class="native" />
@@ -20,7 +20,7 @@
     <property name="shortName" column="shortname" not-null="true" unique="false" length="50" />
 
     <set name="children" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="parentid" />
       <one-to-many class="org.hisp.dhis.organisationunit.OrganisationUnit" />
     </set>
@@ -47,31 +47,31 @@
     <property name="url" />
 
     <set name="dataSets" table="datasetsource" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="sourceid" />
       <many-to-many class="org.hisp.dhis.dataset.DataSet" column="datasetid" />
     </set>
 
     <set name="programs" table="program_organisationunits" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="organisationunitid" />
       <many-to-many class="org.hisp.dhis.program.Program" column="programid" />
     </set>
 
     <set name="groups" table="orgunitgroupmembers" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="organisationunitid" />
       <many-to-many class="org.hisp.dhis.organisationunit.OrganisationUnitGroup" column="orgunitgroupid" />
     </set>
 
     <set name="users" table="usermembership" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="organisationunitid" />
       <many-to-many class="org.hisp.dhis.user.User" column="userinfoid" />
     </set>
 
     <set name="categoryOptions" table="categoryoption_organisationunits" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="organisationunitid" />
       <many-to-many class="org.hisp.dhis.category.CategoryOption" column="categoryoptionid" />
     </set>
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroup.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroup.hbm.xml
index b2a971844317..da3cc6a9aa3c 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroup.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroup.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.organisationunit.OrganisationUnitGroup" table="orgunitgroup">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="orgunitgroupid">
       <generator class="native" />
@@ -28,14 +28,14 @@
     <property name="translations" type="jblTranslations"/>
 
     <set name="members" table="orgunitgroupmembers">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="orgunitgroupid" foreign-key="fk_orgunitgroupmembers_orgunitgroupid" />
       <many-to-many class="org.hisp.dhis.organisationunit.OrganisationUnit" column="organisationunitid"
         foreign-key="fk_orgunitgroup_organisationunitid" />
     </set>
     
     <set name="groupSets" table="orgunitgroupsetmembers" inverse="true">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="orgunitgroupid" />
       <many-to-many class="org.hisp.dhis.organisationunit.OrganisationUnitGroupSet" column="orgunitgroupsetid" />
     </set>
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroupSet.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroupSet.hbm.xml
index 020a3d21b061..085e5e50fd81 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroupSet.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroupSet.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.organisationunit.OrganisationUnitGroupSet" table="orgunitgroupset">
 
-    <cache usage="read-write"/>
+    <cache usage="nonstrict-read-write"/>
 
     <id name="id" column="orgunitgroupsetid">
       <generator class="native"/>
@@ -32,7 +32,7 @@
     <property name="translations" type="jblTranslations"/>
 
     <set name="organisationUnitGroups" table="orgunitgroupsetmembers">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="orgunitgroupsetid" foreign-key="fk_orgunitgroupsetmembers_orgunitgroupsetid" />
       <many-to-many class="org.hisp.dhis.organisationunit.OrganisationUnitGroup" column="orgunitgroupid"
         foreign-key="fk_orgunitgroupset_orgunitgroupid" />
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroupSetDimension.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroupSetDimension.hbm.xml
index 92bd53fa7bd3..7c10e3889f92 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroupSetDimension.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitGroupSetDimension.hbm.xml
@@ -6,7 +6,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.organisationunit.OrganisationUnitGroupSetDimension" table="orgunitgroupsetdimension">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="orgunitgroupsetdimensionid">
       <generator class="native" />
@@ -16,7 +16,7 @@
       foreign-key="fk_dimension_orgunitgroupsetid" />
     
     <list name="items" table="orgunitgroupsetdimension_items">
-      <cache usage="read-write" />
+      <cache usage="nonstrict-read-write" />
       <key column="orgunitgroupsetdimensionid" foreign-key="fk_dimension_items_orgunitgroupsetdimensionid" />
       <list-index column="sort_order" />
       <many-to-many class="org.hisp.dhis.organisationunit.OrganisationUnitGroup" column="orgunitgroupid"
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitLevel.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitLevel.hbm.xml
index 0afc27954c7b..b39a79ed93f7 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitLevel.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/organisationunit/hibernate/OrganisationUnitLevel.hbm.xml
@@ -8,7 +8,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.organisationunit.OrganisationUnitLevel" table="orgunitlevel">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="orgunitlevelid">
       <generator class="native" />
diff --git a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/period/hibernate/PeriodType.hbm.xml b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/period/hibernate/PeriodType.hbm.xml
index 58abbb570242..909fddd6219d 100644
--- a/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/period/hibernate/PeriodType.hbm.xml
+++ b/dhis-2/dhis-services/dhis-service-core/src/main/resources/org/hisp/dhis/period/hibernate/PeriodType.hbm.xml
@@ -6,7 +6,7 @@
 <hibernate-mapping>
   <class name="org.hisp.dhis.period.PeriodType" table="periodtype">
 
-    <cache usage="read-write" />
+    <cache usage="nonstrict-read-write" />
 
     <id name="id" column="periodtypeid">
       <generator class="native" />

From 5c5d15531f0b999a5811ea917a9d3d58424598ed Mon Sep 17 00:00:00 2001
From: Morten Svanaes <netroms@gmail.com>
Date: Sat, 8 Aug 2026 13:38:16 +0800
Subject: [PATCH 2/5] perf: predefine hot L2 regions in ehcache.xml as
 store-by-reference

Regions created on demand through the jsr107 template are store-by-value:
every get and put copies the entry through SerializingCopier, inside the
READ_WRITE region lock critical section. Predefining a region in
ehcache.xml keeps ehcache-native store-by-reference semantics (Hibernate
caches disassembled, immutable entries, so by-reference is safe; 2.41 ran
Ehcache 2 by-reference for years).

Region list and heap bounds come from measured traffic: the hot metadata
regions from a read/write metadata ramp, plus the tracker-import hot set
(the Option region alone takes ~98M gets per 25 minute import run).
Measured effect in the full combination: SerializingCopier wall samples
236,287 -> 1,057.

AI Assisted
---
 .../src/main/resources/ehcache.xml            | 142 ++++++++++++++++--
 .../cache/HibernateEhcacheConfigFileTest.java |  17 ++-
 2 files changed, 149 insertions(+), 10 deletions(-)

diff --git a/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml b/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml
index 1fdb958ba952..6bbea91eceea 100644
--- a/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml
+++ b/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml
@@ -45,15 +45,139 @@
   </cache>
 
   <!--
-    NOTE: The old configuration did not define specific caches for entities.
-    Entities will use the 'defaultCacheTemplate' settings unless you define
-    specific <cache> elements for them below using their fully qualified class name as the alias.
-    Example:
-    <cache alias="org.hisp.dhis.organisationunit.OrganisationUnit" uses-template="defaultCacheTemplate">
-      <resources>
-        <heap unit="entries">50000</heap> <!- More specific size ->
-      </resources>
-    </cache>
+    l2-cache-truth Phase 4.2 (EXPERIMENT): the hottest Hibernate regions measured in the
+    Phase 3 concurrency baseline are PREDEFINED here as ehcache-native caches. Caches created
+    on demand through the JSR-107 API (hibernate-jcache MissingCacheStrategy.CREATE) get the
+    jsr107 default MutableConfiguration semantics, which force store-BY-VALUE: every get and
+    put serializes the entry (SerializingCopier) INSIDE the READ_WRITE region lock critical
+    section (62k wall samples per Phase 3 read run). Predefined caches keep ehcache-native
+    store-by-reference: no copier, no serialization on the cache path. Hibernate stores
+    disassembled (immutable) cache entries, so by-reference is safe; 2.41 ran Ehcache 2
+    by-reference for years.
+
+    Region list and heap bounds derive from phase3-results.json get counts (top regions by
+    gets across all cells); bounds are sized for large national deployments, not the demo DB.
+    Remaining regions still fall back to the jsr107 template above (bounded, store-by-value).
   -->
 
+  <!-- Entity regions -->
+  <cache alias="org.hisp.dhis.organisationunit.OrganisationUnit">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">200000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.category.CategoryOption">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">100000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.dataelement.DataElement">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">100000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.dataset.DataSet">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">20000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.dataset.DataSetElement">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">200000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.category.Category">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">20000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.category.CategoryOptionCombo">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">500000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.user.User">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">100000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.user.UserGroup">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">50000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.user.UserRole">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">20000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.program.Program">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">10000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.period.PeriodType">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">1000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.period.Period">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">100000</heap></resources>
+  </cache>
+  <!-- Tracker-import hot regions (Phase 4 tracker workload: Option region alone takes
+       ~98M gets per 25-min run; missing these from the predefined list left the hottest
+       path store-by-value) -->
+  <cache alias="org.hisp.dhis.option.Option">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">200000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.trackedentity.TrackedEntityAttribute">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">20000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.trackedentity.TrackedEntityType">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">1000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.option.OptionSet.options">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">20000</heap></resources>
+  </cache>
+
+
+  <!-- Collection regions (element ids only, entries are small) -->
+  <cache alias="org.hisp.dhis.organisationunit.OrganisationUnit.children">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">200000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.category.CategoryCombo.categories">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">20000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.category.CategoryCombo.optionCombos">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">20000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.category.Category.categoryOptions">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">20000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.category.CategoryOptionCombo.categoryOptions">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">500000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.user.UserGroup.managedGroups">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">50000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.user.UserRole.restrictions">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">20000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.user.UserRole.authorities">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">20000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.dataelement.DataElement.dataSetElements">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">100000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.dataelement.DataElement.groups">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">100000</heap></resources>
+  </cache>
+  <cache alias="org.hisp.dhis.dataelement.DataElement.legendSets">
+    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <resources><heap unit="entries">100000</heap></resources>
+  </cache>
+
 </config>
diff --git a/dhis-2/dhis-test-integration/src/test/java/org/hisp/dhis/cache/HibernateEhcacheConfigFileTest.java b/dhis-2/dhis-test-integration/src/test/java/org/hisp/dhis/cache/HibernateEhcacheConfigFileTest.java
index af233e2f795c..27698435174f 100644
--- a/dhis-2/dhis-test-integration/src/test/java/org/hisp/dhis/cache/HibernateEhcacheConfigFileTest.java
+++ b/dhis-2/dhis-test-integration/src/test/java/org/hisp/dhis/cache/HibernateEhcacheConfigFileTest.java
@@ -46,6 +46,7 @@
 import org.hibernate.cache.jcache.internal.JCacheRegionFactory;
 import org.hibernate.cache.spi.RegionFactory;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
+import org.hisp.dhis.attribute.Attribute;
 import org.hisp.dhis.cache.HibernateEhcacheConfigFileTest.DhisConfig;
 import org.hisp.dhis.external.conf.ConfigurationKey;
 import org.hisp.dhis.test.config.PostgresTestConfigOverride;
@@ -86,6 +87,13 @@ public PostgresTestConfigOverride postgresTestConfigOverride() {
   /** Heap bound from the ehcache.xml default cache template (jsr107:defaults). */
   private static final long EHCACHE_XML_TEMPLATE_HEAP_ENTRIES = 1_000_000;
 
+  /**
+   * Heap bound declared explicitly for the predefined {@code org.hisp.dhis.user.User} region in
+   * ehcache.xml. Hot regions are declared individually so they can be sized and stored by
+   * reference; the rest still inherit the default template above.
+   */
+  private static final long EHCACHE_XML_USER_HEAP_ENTRIES = 100_000;
+
   @Autowired private EntityManagerFactory entityManagerFactory;
 
   @Test
@@ -105,10 +113,17 @@ void cacheManagerIsConfiguredFromEhcacheXml() {
   void regionsCarryTheEhcacheXmlHeapBounds() {
     CacheManager cacheManager = cacheManager();
 
+    // Attribute has no explicit <cache> element, so it must inherit the default template.
     assertEquals(
         EHCACHE_XML_TEMPLATE_HEAP_ENTRIES,
+        heapEntries(cacheManager, Attribute.class.getName()),
+        "entity regions without an explicit declaration must carry the heap bound of the"
+            + " ehcache.xml default template");
+    // User is declared explicitly in ehcache.xml and must carry its own bound, not the template's.
+    assertEquals(
+        EHCACHE_XML_USER_HEAP_ENTRIES,
         heapEntries(cacheManager, User.class.getName()),
-        "entity regions must carry the heap bound of the ehcache.xml default template");
+        "explicitly declared entity regions must carry their own ehcache.xml heap bound");
     assertEquals(
         EHCACHE_XML_TIMESTAMPS_HEAP_ENTRIES,
         heapEntries(cacheManager, "default-update-timestamps-region"),

From a128a2e262137e26d634c1f8c8612971d66e661c Mon Sep 17 00:00:00 2001
From: Morten Svanaes <netroms@gmail.com>
Date: Sun, 9 Aug 2026 00:20:31 +0800
Subject: [PATCH 3/5] test: assert the query count does not grow, instead of
 exact equality

dataElementCountDoesNotScaleQueryCount compares a metadata export with 3
data elements against one with 8 and asserted the two select counts were
equal. With the cache changes in this branch the second export legitimately
issues FEWER selects (21 vs 22): what the first export loaded is still
cached during the second. Assert the invariant the test name and comment
state - the count must not grow - so the test keeps catching a
reintroduced N+1 without failing on a cache improvement.

AI Assisted
---
 .../DataSetMetadataExportServiceQueryCountTest.java | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/dhis-2/dhis-test-integration/src/test/java/org/hisp/dhis/dxf2/metadata/DataSetMetadataExportServiceQueryCountTest.java b/dhis-2/dhis-test-integration/src/test/java/org/hisp/dhis/dxf2/metadata/DataSetMetadataExportServiceQueryCountTest.java
index 98f1ce48e149..8839013065e1 100644
--- a/dhis-2/dhis-test-integration/src/test/java/org/hisp/dhis/dxf2/metadata/DataSetMetadataExportServiceQueryCountTest.java
+++ b/dhis-2/dhis-test-integration/src/test/java/org/hisp/dhis/dxf2/metadata/DataSetMetadataExportServiceQueryCountTest.java
@@ -115,10 +115,15 @@ void dataElementCountDoesNotScaleQueryCount() {
     // DataElement / DataSetElement loads are batched into a single query, so the select count must
     // not grow with the number of data elements. If it does, the N+1 has been reintroduced (e.g. by
     // iterating DataSet.getDataElements() or DataElement.getCategoryCombos() lazily).
-    assertEquals(
-        baseline,
-        withMoreDataElements,
-        "adding data elements must not increase the number of SQL selects");
+    // The count may legitimately DROP between the two measurements: whatever the first export
+    // loaded can still be served from the second level cache during the second one, so this
+    // asserts the invariant the test name states (no growth) rather than exact equality.
+    assertTrue(
+        withMoreDataElements <= baseline,
+        "adding data elements must not increase the number of SQL selects: "
+            + baseline
+            + " -> "
+            + withMoreDataElements);
   }
 
   @Test

From 809d8e332de15aeee2e0678033ec3797a6f727f8 Mon Sep 17 00:00:00 2001
From: Morten Svanaes <netroms@gmail.com>
Date: Wed, 12 Aug 2026 15:24:27 +0800
Subject: [PATCH 4/5] perf: cap the second level cache TTL at one hour

The previous six hour TTL was inherited from the old Ehcache 2 configuration.
TTL is the upper bound on how long a stale cache entry can survive, whether it
went stale through an out-of-band database change (no load ever refreshes an
existing entry for unversioned entities) or through a late cache-put
re-inserting a value just evicted by a concurrent write under
NONSTRICT_READ_WRITE. One hour tightens that bound for every region at the
cost of one reload per entry per hour, which is noise at production request
rates. Instances with stricter staleness expectations can override the whole
file via cache.ehcache.config.file.

Also rewrites the region declaration comments in neutral terms: why declared
caches are store-by-reference while runtime-created ones are forced
store-by-value by the JCache defaults, how the region list and heap bounds
were chosen, and how to tune both from the per-region metrics exposed at
/api/metrics.

AI Assisted
---
 .../src/main/resources/ehcache.xml            | 96 ++++++++++---------
 1 file changed, 50 insertions(+), 46 deletions(-)

diff --git a/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml b/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml
index 6bbea91eceea..f05a53f5407c 100644
--- a/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml
+++ b/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml
@@ -18,9 +18,12 @@
   <!-- Based on old defaultCache settings -->
   <cache-template name="defaultCacheTemplate">
     <expiry>
-      <!-- Time-to-live: 6 hours (Chosen as primary expiry from old config) -->
-      <!-- TTI (Time-to-idle) was also 6 hours, but only one can be specified directly here. -->
-      <ttl unit="seconds">21600</ttl>
+      <!-- Time-to-live: 1 hour. This is the upper bound on how long a stale entry can survive
+           (e.g. after an out-of-band database change, or a late cache-put re-inserting a value
+           just evicted by a concurrent write under NONSTRICT_READ_WRITE). Entries reload once
+           per hour, which is noise at production request rates. TTI (time-to-idle) is not set;
+           only one of the two can be given here. -->
+      <ttl unit="seconds">3600</ttl>
     </expiry>
     <resources>
       <!-- Max 1,000,000 entries on heap -->
@@ -45,138 +48,139 @@
   </cache>
 
   <!--
-    l2-cache-truth Phase 4.2 (EXPERIMENT): the hottest Hibernate regions measured in the
-    Phase 3 concurrency baseline are PREDEFINED here as ehcache-native caches. Caches created
-    on demand through the JSR-107 API (hibernate-jcache MissingCacheStrategy.CREATE) get the
-    jsr107 default MutableConfiguration semantics, which force store-BY-VALUE: every get and
-    put serializes the entry (SerializingCopier) INSIDE the READ_WRITE region lock critical
-    section (62k wall samples per Phase 3 read run). Predefined caches keep ehcache-native
-    store-by-reference: no copier, no serialization on the cache path. Hibernate stores
-    disassembled (immutable) cache entries, so by-reference is safe; 2.41 ran Ehcache 2
-    by-reference for years.
+    The hottest Hibernate regions under concurrent load are DECLARED here as ehcache-native
+    caches. Caches created on demand through the JSR-107 API (hibernate-jcache
+    MissingCacheStrategy.CREATE) get the JCache MutableConfiguration defaults, which force
+    store-BY-VALUE: every get and put serializes the entry (SerializingCopier), and under
+    READ_WRITE that happens inside the region lock critical section. Declared caches keep
+    ehcache-native store-by-reference: no copier, no serialization on the cache path.
+    Hibernate stores disassembled (immutable) cache entries, so by-reference is safe;
+    DHIS2 2.41 ran Ehcache 2 by-reference for years.
 
-    Region list and heap bounds derive from phase3-results.json get counts (top regions by
-    gets across all cells); bounds are sized for large national deployments, not the demo DB.
-    Remaining regions still fall back to the jsr107 template above (bounded, store-by-value).
+    The region list is the measured hottest regions under concurrent tracker import and
+    metadata read load; heap bounds are sized with headroom for large national deployments,
+    not the demo database. Regions not declared here fall back to the jsr107 template above
+    (bounded, store-by-value). Per-region cache metrics (gets, hits, puts, evictions) are
+    exposed via /api/metrics; a region evicting while hot is undersized and should be raised.
   -->
 
   <!-- Entity regions -->
   <cache alias="org.hisp.dhis.organisationunit.OrganisationUnit">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">200000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.category.CategoryOption">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">100000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.dataelement.DataElement">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">100000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.dataset.DataSet">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">20000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.dataset.DataSetElement">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">200000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.category.Category">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">20000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.category.CategoryOptionCombo">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">500000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.user.User">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">100000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.user.UserGroup">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">50000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.user.UserRole">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">20000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.program.Program">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">10000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.period.PeriodType">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">1000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.period.Period">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">100000</heap></resources>
   </cache>
-  <!-- Tracker-import hot regions (Phase 4 tracker workload: Option region alone takes
-       ~98M gets per 25-min run; missing these from the predefined list left the hottest
-       path store-by-value) -->
+  <!-- Tracker-import hot regions: the Option region alone out-reads every other region by
+       roughly two orders of magnitude under concurrent event imports against option-heavy
+       programs, so leaving it undeclared would keep the hottest path store-by-value. -->
   <cache alias="org.hisp.dhis.option.Option">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">200000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.trackedentity.TrackedEntityAttribute">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">20000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.trackedentity.TrackedEntityType">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">1000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.option.OptionSet.options">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">20000</heap></resources>
   </cache>
 
 
   <!-- Collection regions (element ids only, entries are small) -->
   <cache alias="org.hisp.dhis.organisationunit.OrganisationUnit.children">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">200000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.category.CategoryCombo.categories">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">20000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.category.CategoryCombo.optionCombos">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">20000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.category.Category.categoryOptions">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">20000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.category.CategoryOptionCombo.categoryOptions">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">500000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.user.UserGroup.managedGroups">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">50000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.user.UserRole.restrictions">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">20000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.user.UserRole.authorities">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">20000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.dataelement.DataElement.dataSetElements">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">100000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.dataelement.DataElement.groups">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">100000</heap></resources>
   </cache>
   <cache alias="org.hisp.dhis.dataelement.DataElement.legendSets">
-    <expiry><ttl unit="seconds">21600</ttl></expiry>
+    <expiry><ttl unit="seconds">3600</ttl></expiry>
     <resources><heap unit="entries">100000</heap></resources>
   </cache>
 

From b5012ef007154a1d24acc66635d227faea55f49f Mon Sep 17 00:00:00 2001
From: Morten Svanaes <netroms@gmail.com>
Date: Fri, 21 Aug 2026 02:15:14 +0800
Subject: [PATCH 5/5] perf: store all second level cache regions by reference

---
 .../src/main/resources/ehcache.xml            |  21 ++++
 .../cache/StoreByReferenceConfigTest.java     | 115 ++++++++++++++++++
 2 files changed, 136 insertions(+)
 create mode 100644 dhis-2/dhis-support/dhis-support-hibernate/src/test/java/org/hisp/dhis/cache/StoreByReferenceConfigTest.java

diff --git a/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml b/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml
index f05a53f5407c..647ea013050b 100644
--- a/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml
+++ b/dhis-2/dhis-support/dhis-support-hibernate/src/main/resources/ehcache.xml
@@ -14,6 +14,27 @@
     <jsr107:defaults default-template="defaultCacheTemplate" enable-statistics="true"/>
   </service>
 
+  <!-- Store EVERY region by reference, restoring the pre-2.42 semantics.
+
+       Regions not declared below are created at runtime through the JSR-107 API
+       (hibernate-jcache MissingCacheStrategy.CREATE with an empty MutableConfiguration),
+       and the JCache spec defaults that to store-BY-VALUE: Ehcache then serializes and
+       deserializes every entry on every get and put (SerializingCopier), under READ_WRITE
+       inside the region lock critical section. DHIS2 stored all regions by reference from
+       2016 through 2.41 (Ehcache 2); the 2.42 Spring 6 upgrade flipped runtime-created
+       regions to by-value as a silent side effect of that spec default.
+
+       This CacheManager-level default copier overrides the JSR-107 by-value semantics for
+       runtime-created caches (all typed Object/Object), so they store by reference like the
+       declared caches. Safe for Hibernate's use: the cache holds Hibernate-internal
+       disassembled state, never handed to application code, never mutated in place. Entries
+       are consequently no longer required to be Serializable; a deployment overriding this
+       file to add off-heap or disk tiers must configure serializers, exactly as before 2.42.
+       Pinned by StoreByReferenceConfigTest. -->
+  <default-copiers>
+    <copier type="java.lang.Object">org.ehcache.impl.copy.IdentityCopier</copier>
+  </default-copiers>
+
   <!-- Cache template definition (referenced by jsr107:defaults and potentially explicit caches) -->
   <!-- Based on old defaultCache settings -->
   <cache-template name="defaultCacheTemplate">
diff --git a/dhis-2/dhis-support/dhis-support-hibernate/src/test/java/org/hisp/dhis/cache/StoreByReferenceConfigTest.java b/dhis-2/dhis-support/dhis-support-hibernate/src/test/java/org/hisp/dhis/cache/StoreByReferenceConfigTest.java
new file mode 100644
index 000000000000..d3d9f7893996
--- /dev/null
+++ b/dhis-2/dhis-support/dhis-support-hibernate/src/test/java/org/hisp/dhis/cache/StoreByReferenceConfigTest.java
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2004-2026, University of Oslo
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors 
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * 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 OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.hisp.dhis.cache;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
+
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.List;
+import javax.cache.Cache;
+import javax.cache.CacheManager;
+import javax.cache.Caching;
+import javax.cache.configuration.MutableConfiguration;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Pins the storage semantics of the shipped {@code ehcache.xml} for BOTH ways a Hibernate L2 region
+ * comes into existence.
+ *
+ * <p>Regions declared in the file are ehcache-native and store by reference. Regions NOT declared
+ * are created at runtime by hibernate-jcache exactly like {@link #createRuntimeCache(String)}
+ * below: {@code cacheManager.createCache(name, new MutableConfiguration<>())}. The JCache spec
+ * defaults that configuration to store-by-value, which Ehcache implements by serializing and
+ * deserializing every entry on every get and put (SerializingCopier). DHIS2 ran store-by-reference
+ * for every region from 2016 through 2.41 (Ehcache 2); the 2.42 Spring 6 upgrade flipped
+ * runtime-created regions to by-value as a silent side effect of that spec default. The {@code
+ * <default-copiers>} block in ehcache.xml restores by-reference for them; this test fails if that
+ * block is removed.
+ *
+ * <p>By-reference is safe for Hibernate's use: the cache holds Hibernate-internal disassembled
+ * state that is never handed to application code and never mutated in place. Note entries are no
+ * longer required to be {@link java.io.Serializable}; a deployment overriding the file to add
+ * off-heap or disk tiers must configure serializers, exactly as before 2.42.
+ *
+ * @author Morten Svanæs <msvanaes@dhis2.org>
+ */
+class StoreByReferenceConfigTest {
+
+  private CacheManager cacheManager;
+
+  @BeforeEach
+  void setUp() throws Exception {
+    URI config = getClass().getClassLoader().getResource("ehcache.xml").toURI();
+    cacheManager =
+        Caching.getCachingProvider("org.ehcache.jsr107.EhcacheCachingProvider")
+            .getCacheManager(config, getClass().getClassLoader());
+  }
+
+  @AfterEach
+  void tearDown() {
+    if (cacheManager != null) {
+      cacheManager.close();
+    }
+  }
+
+  @Test
+  void runtimeCreatedRegionStoresByReference() {
+    Cache<Object, Object> cache = createRuntimeCache("org.hisp.dhis.test.RuntimeRegion");
+
+    List<String> value = new ArrayList<>(List.of("entry"));
+    cache.put("key", value);
+
+    Object first = cache.get("key");
+    Object second = cache.get("key");
+    assertNotNull(first);
+    assertSame(first, second, "two gets must return the same instance (store-by-reference)");
+    assertSame(value, first, "the cached instance must be the stored one, not a serialized copy");
+  }
+
+  @Test
+  void declaredRegionStoresByReference() {
+    Cache<Object, Object> cache = cacheManager.getCache("org.hisp.dhis.option.Option");
+    assertNotNull(cache, "declared region must exist in ehcache.xml");
+
+    List<String> value = new ArrayList<>(List.of("entry"));
+    cache.put("key", value);
+
+    assertSame(value, cache.get("key"), "declared regions are ehcache-native, by reference");
+  }
+
+  /** Exactly what hibernate-jcache's JCacheRegionFactory.createCache does for missing regions. */
+  private Cache<Object, Object> createRuntimeCache(String name) {
+    return cacheManager.createCache(name, new MutableConfiguration<>());
+  }
+}