From 6ef3eaf7711da4e7bb848d19c9600a966d802795 Mon Sep 17 00:00:00 2001
From: Caleb Rackliffe <calebrackliffe@gmail.com>
Date: Wed, 16 Jun 2021 14:15:40 -0500
Subject: [PATCH 1/3] update IDEA setup generation to mark test/conf as test
 resources

patch by Abe Ratnofsky; reviewed by Caleb Rackliffe and Brandon Williams for CASSANDRA-16745
---
 ide/idea-iml-file.xml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/ide/idea-iml-file.xml b/ide/idea-iml-file.xml
index bb9155daba..4a720ff7f3 100644
--- a/ide/idea-iml-file.xml
+++ b/ide/idea-iml-file.xml
@@ -32,6 +32,7 @@
             <sourceFolder url="file://$MODULE_DIR$/test/long" isTestSource="true" />
             <sourceFolder url="file://$MODULE_DIR$/test/microbench" isTestSource="true" />
             <sourceFolder url="file://$MODULE_DIR$/test/burn" isTestSource="true" />
+            <sourceFolder url="file://$MODULE_DIR$/test/conf" type="java-test-resource" />
             <sourceFolder url="file://$MODULE_DIR$/test/distributed" isTestSource="true" />
             <sourceFolder url="file://$MODULE_DIR$/test/resources" type="java-test-resource" />
             <excludeFolder url="file://$MODULE_DIR$/.idea" />

From d54eff3a4a59c13b405624e5142aee37ef5f0cc6 Mon Sep 17 00:00:00 2001
From: Jacek Lewandowski <lewandowski.jacek@gmail.com>
Date: Tue, 15 Jun 2021 14:07:39 +0200
Subject: [PATCH 2/3] Remove full project building from the generate-idea-files
 ant target

 - that target was unnecessarily building the whole project which made it problematic to update the project while merging/rebasing if conflicts in the code were failing the compilation
 - updated system properties for default run test task in Intellij to match those when running tests from Ant
 - fix test-memory target

 patch by Jacek Lewandowski; reviewed by Mick Semb Wever for CASSANDRA-16697
---
 build.xml              | 2 +-
 ide/idea/workspace.xml | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/build.xml b/build.xml
index 76e84ac043..8dc7dfd493 100644
--- a/build.xml
+++ b/build.xml
@@ -1753,7 +1753,7 @@
   </target>
 
   <!-- Generate IDEA project description files -->
-  <target name="generate-idea-files" depends="build-test" description="Generate IDEA files">
+  <target name="generate-idea-files" depends="init,maven-ant-tasks-retrieve-build,gen-cql3-grammar,createVersionPropFile" description="Generate IDEA files">
     <mkdir dir=".idea"/>
     <mkdir dir=".idea/libraries"/>
     <copy todir=".idea">
diff --git a/ide/idea/workspace.xml b/ide/idea/workspace.xml
index 9cf2d966a5..68408ef4c9 100644
--- a/ide/idea/workspace.xml
+++ b/ide/idea/workspace.xml
@@ -168,7 +168,7 @@
       <option name="MAIN_CLASS_NAME" value="" />
       <option name="METHOD_NAME" value="" />
       <option name="TEST_OBJECT" value="class" />
-      <option name="VM_PARAMETERS" value="-Dcassandra.config=file://$PROJECT_DIR$/test/conf/cassandra.yaml -Dlogback.configurationFile=file://$PROJECT_DIR$/test/conf/logback-test.xml -Dcassandra.logdir=$PROJECT_DIR$/build/test/logs -ea -XX:MaxMetaspaceSize=256M -XX:SoftRefLRUPolicyMSPerMB=0 -Dcassandra.strict.runtime.checks=true" />
+      <option name="VM_PARAMETERS" value="-Dcassandra.config=file://$PROJECT_DIR$/test/conf/cassandra.yaml -Dlogback.configurationFile=file://$PROJECT_DIR$/test/conf/logback-test.xml -Dcassandra.logdir=$PROJECT_DIR$/build/test/logs -ea -XX:MaxMetaspaceSize=256M -XX:SoftRefLRUPolicyMSPerMB=0 -Dcassandra.strict.runtime.checks=true -Dlegacy-sstable-root=$PROJECT_DIR$/test/data/legacy-sstables -Dinvalid-legacy-sstable-root=$PROJECT_DIR$/test/data/invalid-legacy-sstables -Dmigration-sstable-root=$PROJECT_DIR$/test/data/migration-sstables -Dcassandra.ring_delay_ms=1000 -Dcassandra.tolerate_sstable_size=true -Dcassandra.skip_sync=true" />
       <option name="PARAMETERS" value="" />
       <option name="WORKING_DIRECTORY" value="" />
       <option name="ENV_VARIABLES" />

From 9b6dd382bdf4a71c06091736ff98cb1307ff0e97 Mon Sep 17 00:00:00 2001
From: Benjamin Lerer <b.lerer@gmail.com>
Date: Fri, 11 Jun 2021 15:10:54 +0200
Subject: [PATCH 3/3] Add flag to disable ALTER...DROP COMPACT STORAGE
 statements

patch by Benjamin Lerer; review by Andres de la Pena and Brandon Williams for CASSANDRA-16733
---
 CHANGES.txt                                         |  1 +
 NEWS.txt                                            | 13 ++++++++++++-
 conf/cassandra.yaml                                 |  4 ++++
 src/java/org/apache/cassandra/config/Config.java    |  2 ++
 .../apache/cassandra/config/DatabaseDescriptor.java | 11 +++++++++++
 .../cql3/statements/AlterTableStatement.java        |  4 ++++
 test/conf/cassandra.yaml                            |  1 +
 .../upgrade/CompactStorage2to3UpgradeTest.java      |  6 +++++-
 .../distributed/upgrade/DropCompactStorageTest.java |  2 +-
 .../distributed/upgrade/UpgradeTestBase.java        | 11 ++++++++++-
 .../cql3/validation/operations/AlterTest.java       | 11 +++++++++++
 11 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index 102989288c..335050d254 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 3.0.25:
+ * Add flag to disable ALTER...DROP COMPACT STORAGE statements (CASSANDRA-16733)
  * Clean transaction log leftovers at the beginning of sstablelevelreset and sstableofflinerelevel (CASSANDRA-12519)
  * CQL shell should prefer newer TLS version by default (CASSANDRA-16695)
  * Ensure that existing empty rows are properly returned (CASSANDRA-16671)
diff --git a/NEWS.txt b/NEWS.txt
index 6cc5e84dc8..889943bfe0 100644
--- a/NEWS.txt
+++ b/NEWS.txt
@@ -42,6 +42,16 @@ restore snapshots created with the previous major version using the
 'sstableloader' tool. You can upgrade the file format of your snapshots
 using the provided 'sstableupgrade' tool.
 
+3.0.25
+======
+
+ALTER ... DROP COMPACT STORAGE
+------------------------------
+   - Following a discussion regarding concerns about the safety of the 'ALTER ... DROP COMPACT STORAGE' statement,
+     the C* development community does not recommend its use in production and considers it experimental
+     (see https://www.mail-archive.com/dev@cassandra.apache.org/msg16789.html).
+   - An 'enable_drop_compact_storage' flag has been added to cassandra.yaml to allow operators to prevent its use.
+
 3.0.24
 ======
 
@@ -139,7 +149,8 @@ Upgrading
 
 Compact Storage
 ---------------
-    - Starting version 4.0, Thrift and COMPACT STORAGE is no longer supported.
+    - Starting version 4.0, Thrift is no longer supported.
+      Starting version 5.0, COMPACT STORAGE will no longer be supported.
       'ALTER ... DROP COMPACT STORAGE' statement makes Compact Tables CQL-compatible,
       exposing internal structure of Thrift/Compact Tables. You can find more details
       on exposed internal structure under: 
diff --git a/conf/cassandra.yaml b/conf/cassandra.yaml
index bb96f18146..cc2a3690f4 100644
--- a/conf/cassandra.yaml
+++ b/conf/cassandra.yaml
@@ -989,6 +989,10 @@ enable_scripted_user_defined_functions: false
 # Materialized views are considered experimental and are not recommended for production use.
 enable_materialized_views: true
 
+# Enables the used of 'ALTER ... DROP COMPACT STORAGE' statements on this node.
+# 'ALTER ... DROP COMPACT STORAGE' is considered experimental and is not recommended for production use.
+enable_drop_compact_storage: false
+
 # The default Windows kernel timer and scheduling resolution is 15.6ms for power conservation.
 # Lowering this value on Windows can provide much tighter latency and better throughput, however
 # some virtualized environments may see a negative performance impact from changing this setting
diff --git a/src/java/org/apache/cassandra/config/Config.java b/src/java/org/apache/cassandra/config/Config.java
index cd74b6140d..7aaabe3e66 100644
--- a/src/java/org/apache/cassandra/config/Config.java
+++ b/src/java/org/apache/cassandra/config/Config.java
@@ -322,6 +322,8 @@ public class Config
 
     public boolean enable_materialized_views = true;
 
+    public volatile boolean enable_drop_compact_storage = true;
+
     /**
      * Optionally disable asynchronous UDF execution.
      * Disabling asynchronous UDF execution also implicitly disables the security-manager!
diff --git a/src/java/org/apache/cassandra/config/DatabaseDescriptor.java b/src/java/org/apache/cassandra/config/DatabaseDescriptor.java
index 656828cb16..b7708cdf3a 100644
--- a/src/java/org/apache/cassandra/config/DatabaseDescriptor.java
+++ b/src/java/org/apache/cassandra/config/DatabaseDescriptor.java
@@ -2169,6 +2169,17 @@ public class DatabaseDescriptor
         return conf.enable_materialized_views;
     }
 
+    public static boolean enableDropCompactStorage()
+    {
+        return conf.enable_drop_compact_storage;
+    }
+
+    @VisibleForTesting
+    public static void setEnableDropCompactStorage(boolean enableDropCompactStorage)
+    {
+        conf.enable_drop_compact_storage = enableDropCompactStorage;
+    }
+
     public static long getUserDefinedFunctionFailTimeout()
     {
         return conf.user_defined_function_fail_timeout;
diff --git a/src/java/org/apache/cassandra/cql3/statements/AlterTableStatement.java b/src/java/org/apache/cassandra/cql3/statements/AlterTableStatement.java
index 76e891f38e..c023183ee9 100644
--- a/src/java/org/apache/cassandra/cql3/statements/AlterTableStatement.java
+++ b/src/java/org/apache/cassandra/cql3/statements/AlterTableStatement.java
@@ -290,6 +290,10 @@ public class AlterTableStatement extends SchemaAlteringStatement
                                                                     columnFamily()));
                 break;
             case DROP_COMPACT_STORAGE:
+
+                if (!DatabaseDescriptor.enableDropCompactStorage())
+                    throw new InvalidRequestException("DROP COMPACT STORAGE is disabled. Enable in cassandra.yaml to use.");
+
                 if (!meta.isCompactTable())
                     throw new InvalidRequestException("Cannot DROP COMPACT STORAGE on table without COMPACT STORAGE");
 
diff --git a/test/conf/cassandra.yaml b/test/conf/cassandra.yaml
index 1dba2845a0..2536aa8530 100644
--- a/test/conf/cassandra.yaml
+++ b/test/conf/cassandra.yaml
@@ -41,3 +41,4 @@ row_cache_class_name: org.apache.cassandra.cache.OHCProvider
 row_cache_size_in_mb: 16
 enable_user_defined_functions: true
 enable_scripted_user_defined_functions: true
+enable_drop_compact_storage: true
diff --git a/test/distributed/org/apache/cassandra/distributed/upgrade/CompactStorage2to3UpgradeTest.java b/test/distributed/org/apache/cassandra/distributed/upgrade/CompactStorage2to3UpgradeTest.java
index 032befadbd..37e8bb4bc8 100644
--- a/test/distributed/org/apache/cassandra/distributed/upgrade/CompactStorage2to3UpgradeTest.java
+++ b/test/distributed/org/apache/cassandra/distributed/upgrade/CompactStorage2to3UpgradeTest.java
@@ -165,6 +165,10 @@ public class CompactStorage2to3UpgradeTest extends UpgradeTestBase
 
                     });
 
+                }).runBeforeNodeRestart((cluster, node) ->
+                {
+                    cluster.get(node).config().set("enable_drop_compact_storage", true);
+
                 }).runAfterClusterUpgrade(cluster ->
                 {
                     for (int i = 1; i <= cluster.size(); i++)
@@ -207,7 +211,7 @@ public class CompactStorage2to3UpgradeTest extends UpgradeTestBase
         new TestCase()
                 .nodes(2)
                 .upgrade(Versions.Major.v22, Versions.Major.v30)
-                .withConfig(config -> config.with(GOSSIP, NETWORK, NATIVE_PROTOCOL))
+                .withConfig(config -> config.with(GOSSIP, NETWORK, NATIVE_PROTOCOL).set("enable_drop_compact_storage", true))
                 .setup(cluster -> {
                     cluster.schemaChange(String.format(
                             "CREATE TABLE %s.%s (key int, c1 int, c2 int, c3 int, PRIMARY KEY (key, c1, c2)) WITH COMPACT STORAGE",
diff --git a/test/distributed/org/apache/cassandra/distributed/upgrade/DropCompactStorageTest.java b/test/distributed/org/apache/cassandra/distributed/upgrade/DropCompactStorageTest.java
index 8207448579..417af4e1e6 100644
--- a/test/distributed/org/apache/cassandra/distributed/upgrade/DropCompactStorageTest.java
+++ b/test/distributed/org/apache/cassandra/distributed/upgrade/DropCompactStorageTest.java
@@ -48,7 +48,7 @@ public class DropCompactStorageTest extends UpgradeTestBase
         new TestCase()
         .nodes(1)
         .upgrade(Versions.Major.v22, upgradeTo)
-        .withConfig(config -> config.with(GOSSIP, NETWORK, NATIVE_PROTOCOL))
+        .withConfig(config -> config.with(GOSSIP, NETWORK, NATIVE_PROTOCOL).set("enable_drop_compact_storage", true))
         .setup((cluster) -> {
             cluster.schemaChange("CREATE TABLE " + KEYSPACE + ".tbl (id int, ck int, v int, PRIMARY KEY (id, ck)) WITH COMPACT STORAGE");
             for (int i = 0; i < 5; i++)
diff --git a/test/distributed/org/apache/cassandra/distributed/upgrade/UpgradeTestBase.java b/test/distributed/org/apache/cassandra/distributed/upgrade/UpgradeTestBase.java
index 4f0c70058a..de2940889a 100644
--- a/test/distributed/org/apache/cassandra/distributed/upgrade/UpgradeTestBase.java
+++ b/test/distributed/org/apache/cassandra/distributed/upgrade/UpgradeTestBase.java
@@ -31,7 +31,6 @@ import org.junit.BeforeClass;
 import org.apache.cassandra.distributed.UpgradeableCluster;
 import org.apache.cassandra.distributed.api.ICluster;
 import org.apache.cassandra.distributed.api.IInstanceConfig;
-import org.apache.cassandra.distributed.api.IUpgradeableInstance;
 import org.apache.cassandra.distributed.impl.Instance;
 import org.apache.cassandra.distributed.shared.DistributedTestBase;
 import org.apache.cassandra.distributed.shared.Versions;
@@ -89,6 +88,7 @@ public class UpgradeTestBase extends DistributedTestBase
         private final List<TestVersions> upgrade = new ArrayList<>();
         private int nodeCount = 3;
         private RunOnCluster setup;
+        private RunOnClusterAndNode runBeforeNodeRestart;
         private RunOnClusterAndNode runAfterNodeUpgrade;
         private RunOnCluster runAfterClusterUpgrade;
         private final Set<Integer> nodesToUpgrade = new HashSet<>();
@@ -131,6 +131,12 @@ public class UpgradeTestBase extends DistributedTestBase
             return this;
         }
 
+        public TestCase runBeforeNodeRestart(RunOnClusterAndNode runBeforeNodeRestart)
+        {
+            this.runBeforeNodeRestart = runBeforeNodeRestart;
+            return this;
+        }
+
         public TestCase runAfterNodeUpgrade(RunOnClusterAndNode runAfterNodeUpgrade)
         {
             this.runAfterNodeUpgrade = runAfterNodeUpgrade;
@@ -157,6 +163,8 @@ public class UpgradeTestBase extends DistributedTestBase
                 throw new AssertionError();
             if (runAfterClusterUpgrade == null && runAfterNodeUpgrade == null)
                 throw new AssertionError();
+            if (runBeforeNodeRestart == null)
+                runBeforeNodeRestart = (c, n) -> {};
             if (runAfterClusterUpgrade == null)
                 runAfterClusterUpgrade = (c) -> {};
             if (runAfterNodeUpgrade == null)
@@ -177,6 +185,7 @@ public class UpgradeTestBase extends DistributedTestBase
                         {
                             cluster.get(n).shutdown().get();
                             cluster.get(n).setVersion(version);
+                            runBeforeNodeRestart.run(cluster, n);
                             cluster.get(n).startup();
                             runAfterNodeUpgrade.run(cluster, n);
                         }
diff --git a/test/unit/org/apache/cassandra/cql3/validation/operations/AlterTest.java b/test/unit/org/apache/cassandra/cql3/validation/operations/AlterTest.java
index 20493807c0..86a90b758e 100644
--- a/test/unit/org/apache/cassandra/cql3/validation/operations/AlterTest.java
+++ b/test/unit/org/apache/cassandra/cql3/validation/operations/AlterTest.java
@@ -20,6 +20,7 @@ package org.apache.cassandra.cql3.validation.operations;
 import org.junit.Assert;
 import org.junit.Test;
 
+import org.apache.cassandra.config.DatabaseDescriptor;
 import org.apache.cassandra.cql3.CQLTester;
 import org.apache.cassandra.db.ColumnFamilyStore;
 import org.apache.cassandra.db.Keyspace;
@@ -547,4 +548,14 @@ public class AlterTest extends CQLTester
         assertInvalidMessage(table2, format("ALTER TYPE %s.%s ADD v2 int;", keyspace(), type1));
         assertInvalidMessage(table3, format("ALTER TYPE %s.%s ADD v2 int;", keyspace(), type1));
     }
+
+    @Test
+    public void testAlterDropCompactStorageDisabled() throws Throwable
+    {
+        DatabaseDescriptor.setEnableDropCompactStorage(false);
+
+        createTable("CREATE TABLE %s (k text, i int, PRIMARY KEY (k, i)) WITH COMPACT STORAGE");
+
+        assertInvalidMessage("DROP COMPACT STORAGE is disabled. Enable in cassandra.yaml to use.", "ALTER TABLE %s DROP COMPACT STORAGE");
+    }
 }