chore(crdb): remove support for cockroach db from code base

.github/helpers/pr-labels.yml

@@ -17,9 +17,6 @@
 - name: "ci:all-db"
   description: "Runs the builds for all databases."
   color: "cccccc"
-- name: "ci:cockroachdb"
-  description: "Runs the builds for the CockroachDB database."
-  color: "cccccc"
 - name: "ci:db2"
   description: "Runs the builds for the DB2 database."
   color: "cccccc"

TESTING.md

@@ -75,7 +75,7 @@ There is a special profile for the WildFly Application Servers:
 
 # Testing a Given Database
 
-Camunda supports all database technologies listed on [Supported Database Products](https://docs.camunda.org/manual/latest/introduction/supported-environments/#supported-database-products), and in all environments, they are operating in as specified. Support means we guarantee the Camunda Platform integrates well with the database technology’s JDBC behavior (there are some [documented](https://docs.camunda.org/manual/latest/user-guide/process-engine/database/) limitations, e.g., isolation level `READ_COMMITTED` is required for all databases except CockroachDB, which in turns requires `SERIALIZABLE`). We test a database technology with a specific database, i.e., we test it in one environment, not all possible environments that you can imagine (e.g., we test Postgres on local Docker containers, but not as hosted databases on AWS or Azure).
+Camunda supports all database technologies listed on [Supported Database Products](https://docs.camunda.org/manual/latest/introduction/supported-environments/#supported-database-products), and in all environments, they are operating in as specified. Support means we guarantee the Camunda Platform integrates well with the database technology’s JDBC behavior (there are some [documented](https://docs.camunda.org/manual/latest/user-guide/process-engine/database/) limitations, e.g., isolation level `READ_COMMITTED` is required for all databases). We test a database technology with a specific database, i.e., we test it in one environment, not all possible environments that you can imagine (e.g., we test Postgres on local Docker containers, but not as hosted databases on AWS or Azure).
 
 # No Maven? No problem!
 
@@ -137,7 +137,6 @@ sure that the database image is configured according to [this guide](https://doc
 * PostgreSQL
 * MariaDB
 * MySQL
-* CockroachDB
 * MS-SQL 2017/2019 ([MSSQL-specific configuraion guide](https://docs.camunda.org/manual/latest/user-guide/process-engine/database/mssql-configuration/))
 
 To execute the process engine test suite with a certain database (e.g. PostgreSQL), you should call Maven in the 

database/pom.xml

@@ -29,10 +29,6 @@
     <version.postgresql>42.5.5</version.postgresql>
     <version.liquibase>4.8.0</version.liquibase>
 
-    <!-- CockroachDB is compatible with PostgreSQL 9.5,
-    so a different version of the JDBC driver needs to be used -->
-    <version.cockroachdb>42.2.9</version.cockroachdb>
-
     <!-- needed for sql script and backward compatibility checks -->
     <camunda.version.old>7.21.0</camunda.version.old>
 
@@ -383,44 +379,6 @@
         <was.liberty.datasource.filename>postgresql-xa-config.xml</was.liberty.datasource.filename>
       </properties>
     </profile>
-    <profile>
-      <id>cockroachdb</id>
-      <properties>
-        <database.type>cockroachdb</database.type>
-        <database.driver>org.postgresql.Driver</database.driver>
-        <database.datasource.class>org.postgresql.ds.PGSimpleDataSource</database.datasource.class>
-        <jboss.datasource.filename>postgresql-ds.xml</jboss.datasource.filename>
-        <hibernate.dialect>org.hibernate.dialect.PostgreSQLDialect</hibernate.dialect>
-        <database.tc.url>camcockroachdb:20.1.3</database.tc.url>
-      </properties>
-
-      <dependencies>
-        <dependency>
-          <groupId>org.postgresql</groupId>
-          <artifactId>postgresql</artifactId>
-          <version>${version.cockroachdb}</version>
-          <scope>test</scope>
-        </dependency>
-      </dependencies>
-      <build>
-        <pluginManagement>
-          <plugins>
-            <plugin>
-              <groupId>org.codehaus.mojo</groupId>
-              <artifactId>sql-maven-plugin</artifactId>
-              <dependencies>
-                <dependency>
-                  <groupId>org.postgresql</groupId>
-                  <artifactId>postgresql</artifactId>
-                  <version>${version.cockroachdb}</version>
-                </dependency>
-              </dependencies>
-            </plugin>
-          </plugins>
-        </pluginManagement>
-      </build>
-    </profile>
-
     <profile>
       <id>sqlserver</id>
       <properties>

distro/sql-script/pom.xml

@@ -204,10 +204,6 @@
                   <filelist dir="target/camunda-engine-${project.version}/org/camunda/bpm/engine/db/create" files="activiti.postgres.create.engine.sql activiti.postgres.create.case.engine.sql activiti.postgres.create.decision.engine.sql activiti.postgres.create.history.sql activiti.postgres.create.case.history.sql activiti.postgres.create.decision.history.sql" />
                 </concat>
 
-                <concat destfile="target/sql/create/cockroachdb_engine_${project.version}.sql" fixlastline="yes">
-                  <filelist dir="target/camunda-engine-${project.version}/org/camunda/bpm/engine/db/create" files="activiti.cockroachdb.create.engine.sql activiti.cockroachdb.create.case.engine.sql activiti.cockroachdb.create.decision.engine.sql activiti.cockroachdb.create.history.sql activiti.cockroachdb.create.case.history.sql activiti.cockroachdb.create.decision.history.sql" />
-                </concat>
-
                 <!-- add identity create files -->
                 <copy todir="target/sql/create" flatten="false">
                   <fileset dir="target/camunda-engine-${project.version}/org/camunda/bpm/engine/db/create" />
@@ -250,10 +246,6 @@
                   <filelist dir="target/camunda-engine-${project.version}/org/camunda/bpm/engine/db/drop" files="activiti.postgres.drop.decision.engine.sql activiti.postgres.drop.case.engine.sql activiti.postgres.drop.engine.sql activiti.postgres.drop.decision.history.sql activiti.postgres.drop.case.history.sql activiti.postgres.drop.history.sql" />
                 </concat>
 
-                <concat destfile="target/sql/drop/cockroachdb_engine_${project.version}.sql" fixlastline="yes">
-                  <filelist dir="target/camunda-engine-${project.version}/org/camunda/bpm/engine/db/drop" files="activiti.cockroachdb.drop.decision.engine.sql activiti.cockroachdb.drop.case.engine.sql activiti.cockroachdb.drop.engine.sql activiti.cockroachdb.drop.decision.history.sql activiti.cockroachdb.drop.case.history.sql activiti.cockroachdb.drop.history.sql" />
-                </concat>
-
                 <!-- add identity drop files -->
                 <copy todir="target/sql/drop" flatten="false">
                   <fileset dir="target/camunda-engine-${project.version}/org/camunda/bpm/engine/db/drop" />
@@ -355,15 +347,6 @@
                   <fileset dir="target/camunda-engine-${project.version}/org/camunda/bpm/engine/db/upgrade" includes="postgres_engine_${camunda.old.majorVersion}.${camunda.old.minorVersion}_patch*.sql" />
                 </concat>
 
-                <!-- cockroachdb patches -->
-                <concat destfile="target/upgrade-test/sql/upgrade/cockroachdb_engine_${camunda.current.majorVersion}.${camunda.current.minorVersion}_patch.sql" fixlastline="yes">
-                  <fileset dir="target/camunda-engine-${project.version}/org/camunda/bpm/engine/db/upgrade" includes="cockroachdb_engine_${camunda.current.majorVersion}.${camunda.current.minorVersion}_patch*.sql" />
-                </concat>
-
-                <concat destfile="target/upgrade-test/sql/upgrade/cockroachdb_engine_${camunda.old.majorVersion}.${camunda.old.minorVersion}_patch.sql" fixlastline="yes">
-                  <fileset dir="target/camunda-engine-${project.version}/org/camunda/bpm/engine/db/upgrade" includes="cockroachdb_engine_${camunda.old.majorVersion}.${camunda.old.minorVersion}_patch*.sql" />
-                </concat>
-
                 <copy todir="target/upgrade-test/sql/upgrade">
                   <fileset dir="target/camunda-engine-${project.version}/org/camunda/bpm/engine/db/upgrade">
                     <include name="*.sql" />

engine-spring/core/src/main/java/org/camunda/bpm/engine/spring/SpringTransactionInterceptor.java

@@ -16,17 +16,11 @@
  */
 package org.camunda.bpm.engine.spring;
 
-import java.sql.SQLException;
-import java.util.logging.Logger;
-
-import org.camunda.bpm.engine.impl.ProcessEngineLogger;
 import org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl;
-import org.camunda.bpm.engine.impl.db.sql.DbSqlSession;
 import org.camunda.bpm.engine.impl.interceptor.Command;
 import org.camunda.bpm.engine.impl.interceptor.CommandInterceptor;
 import org.camunda.bpm.engine.impl.util.ExceptionUtil;
 import org.springframework.transaction.PlatformTransactionManager;
-import org.springframework.transaction.TransactionStatus;
 import org.springframework.transaction.TransactionSystemException;
 import org.springframework.transaction.support.TransactionCallback;
 import org.springframework.transaction.support.TransactionTemplate;
@@ -71,18 +65,7 @@ public <T> T execute(final Command<T> command) {
       // don't use lambdas here => CAM-12810
       return (T) transactionTemplate.execute((TransactionCallback) status -> next.execute(command));
     } catch (TransactionSystemException ex) {
-      // When CockroachDB is used, a CRDB concurrency error may occur on transaction commit.
-      // To ensure that these errors are still detected as OLEs, we must catch them and wrap
-      // them in a CrdbTransactionRetryException
-      Throwable cause = ex.getCause();
-      if (cause instanceof SQLException && processEngineConfiguration != null
-              && DbSqlSession.isCrdbConcurrencyConflictOnCommit((SQLException) cause, processEngineConfiguration)) {
-        throw ProcessEngineLogger.PERSISTENCE_LOGGER.crdbTransactionRetryExceptionOnCommit(cause);
-
-      } else {
-        throw ExceptionUtil.wrapPersistenceException(ex);
-
-      }
+      throw ExceptionUtil.wrapPersistenceException(ex);
     }
   }
 }

engine-spring/core/src/main/java/org/camunda/bpm/engine/spring/SpringTransactionsProcessEngineConfiguration.java

@@ -29,7 +29,6 @@
 import org.camunda.bpm.engine.RepositoryService;
 import org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl;
 import org.camunda.bpm.engine.impl.cfg.StandaloneProcessEngineConfiguration;
-import org.camunda.bpm.engine.impl.db.sql.DbSqlSessionFactory;
 import org.camunda.bpm.engine.impl.interceptor.CommandContextInterceptor;
 import org.camunda.bpm.engine.impl.interceptor.CommandCounterInterceptor;
 import org.camunda.bpm.engine.impl.interceptor.CommandInterceptor;
@@ -74,11 +73,6 @@ public ProcessEngine buildProcessEngine() {
     }
 
     List<CommandInterceptor> defaultCommandInterceptorsTxRequired = new ArrayList<CommandInterceptor>();
-    // CRDB interceptor is added before the SpringTransactionInterceptor,
-    // so that a Spring TX may be rolled back before retrying.
-    if (DbSqlSessionFactory.CRDB.equals(databaseType)) {
-      defaultCommandInterceptorsTxRequired.add(getCrdbRetryInterceptor());
-    }
     if (!isDisableExceptionCode()) {
       defaultCommandInterceptorsTxRequired.add(getExceptionCodeInterceptor());
     }
@@ -93,11 +87,6 @@ public ProcessEngine buildProcessEngine() {
 
   protected Collection< ? extends CommandInterceptor> getDefaultCommandInterceptorsTxRequiresNew() {
     List<CommandInterceptor> defaultCommandInterceptorsTxRequiresNew = new ArrayList<CommandInterceptor>();
-    // CRDB interceptor is added before the SpringTransactionInterceptor,
-    // so that a Spring TX may be rolled back before retrying.
-    if (DbSqlSessionFactory.CRDB.equals(databaseType)) {
-      defaultCommandInterceptorsTxRequiresNew.add(getCrdbRetryInterceptor());
-    }
     if (!isDisableExceptionCode()) {
       defaultCommandInterceptorsTxRequiresNew.add(getExceptionCodeInterceptor());
     }