Cassandra based distributed locking mechanism # 741

- Cassandra tables called lock and lock_priority,
 to manage task execution and synchronization across
 multiple nodes.

CHANGES.md

@@ -2,6 +2,7 @@
 
 ## Version 1.0.0 (Not yet Released)
 
+* Cassandra-Based Distributed Locks #741
 * Investigate Creation of RepairScheduler and ScheduleManager #714
 * Implement ScheduledJobQueue for Prioritized Job Management and Execution - Issue #740
 * Implement RepairGroup Class for Managing and Executing Repair Tasks - Issue #738

core.impl/src/main/java/com/ericsson/bss/cassandra/ecchronos/core/impl/locks/CASLock.java

@@ -30,7 +30,7 @@
 
 import com.datastax.oss.driver.api.core.cql.ResultSet;
 import com.datastax.oss.driver.api.core.cql.Row;
-import com.ericsson.bss.cassandra.ecchronos.core.utils.LockException;
+import com.ericsson.bss.cassandra.ecchronos.utils.exceptions.LockException;
 
 /**
  * Represents a container for builder configurations and state for the CASLock.
@@ -213,5 +213,4 @@ int getFailedAttempts()
     {
         return myFailedUpdateAttempts.get();
     }
-
 }

core.impl/src/main/java/com/ericsson/bss/cassandra/ecchronos/core/impl/locks/CASLockFactory.java

@@ -23,9 +23,9 @@
 import com.datastax.oss.driver.api.core.metadata.TokenMap;
 import com.datastax.oss.driver.api.core.metadata.schema.KeyspaceMetadata;
 import com.datastax.oss.driver.api.core.metadata.schema.TableMetadata;
-import com.ericsson.bss.cassandra.ecchronos.core.utils.LockException;
-import com.ericsson.bss.cassandra.ecchronos.core.locks.HostStates;
 import com.ericsson.bss.cassandra.ecchronos.core.locks.LockFactory;
+import com.ericsson.bss.cassandra.ecchronos.utils.exceptions.LockException;
+import com.ericsson.bss.cassandra.ecchronos.core.locks.HostStates;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import org.slf4j.Logger;
@@ -140,9 +140,9 @@ private int getDefaultTimeToLiveFromLockTable()
 
     @Override
     public DistributedLock tryLock(final String dataCenter,
-                                   final String resource,
-                                   final int priority,
-                                   final Map<String, String> metadata)
+                                               final String resource,
+                                               final int priority,
+                                               final Map<String, String> metadata)
                                                                        throws LockException
     {
         return myCasLockFactoryCacheContext.getLockCache()

core.impl/src/main/java/com/ericsson/bss/cassandra/ecchronos/core/impl/locks/LockCache.java

@@ -15,8 +15,7 @@
 package com.ericsson.bss.cassandra.ecchronos.core.impl.locks;
 
 import static com.ericsson.bss.cassandra.ecchronos.core.locks.LockFactory.DistributedLock;
-
-import com.ericsson.bss.cassandra.ecchronos.core.utils.LockException;
+import com.ericsson.bss.cassandra.ecchronos.utils.exceptions.LockException;
 import com.github.benmanes.caffeine.cache.Cache;
 import com.github.benmanes.caffeine.cache.Caffeine;
 import org.slf4j.Logger;

core.impl/src/main/java/com/ericsson/bss/cassandra/ecchronos/core/impl/utils/package-info.java

@@ -16,3 +16,4 @@
  * Contains utilities classes.
  */
 package com.ericsson.bss.cassandra.ecchronos.core.impl.utils;
+

core.impl/src/test/java/com/ericsson/bss/cassandra/ecchronos/core/impl/locks/TestCASLockFactory.java

@@ -28,6 +28,7 @@
 import com.ericsson.bss.cassandra.ecchronos.core.impl.utils.ConsistencyType;
 import com.ericsson.bss.cassandra.ecchronos.core.locks.HostStates;
 import com.ericsson.bss.cassandra.ecchronos.core.locks.LockFactory;
+import com.ericsson.bss.cassandra.ecchronos.utils.exceptions.LockException;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collection;
@@ -69,8 +70,6 @@
 import org.junit.Before;
 import org.junit.Test;
 
-import com.ericsson.bss.cassandra.ecchronos.core.utils.LockException;
-
 import net.jcip.annotations.NotThreadSafe;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;

core.impl/src/test/java/com/ericsson/bss/cassandra/ecchronos/core/impl/locks/TestLockCache.java

@@ -14,7 +14,7 @@
  */
 package com.ericsson.bss.cassandra.ecchronos.core.impl.locks;
 
-import com.ericsson.bss.cassandra.ecchronos.core.utils.LockException;
+import com.ericsson.bss.cassandra.ecchronos.utils.exceptions.LockException;
 import com.ericsson.bss.cassandra.ecchronos.core.locks.LockFactory.DistributedLock;
 import nl.jqno.equalsverifier.EqualsVerifier;
 import org.junit.Before;

core/src/main/java/com/ericsson/bss/cassandra/ecchronos/core/locks/LockFactory.java

@@ -17,8 +17,7 @@
 import java.io.Closeable;
 import java.util.Map;
 import java.util.Optional;
-
-import com.ericsson.bss.cassandra.ecchronos.core.utils.LockException;
+import com.ericsson.bss.cassandra.ecchronos.utils.exceptions.LockException;
 
 /**
  * Interface for distributed lock factories.

core/src/main/java/com/ericsson/bss/cassandra/ecchronos/core/utils/LockException.java → utils/src/main/java/com/ericsson/bss/cassandra/ecchronos/utils/exceptions/LockException.java

@@ -12,7 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.ericsson.bss.cassandra.ecchronos.core.utils;
+package com.ericsson.bss.cassandra.ecchronos.utils.exceptions;
 
 /**
  * Exception thrown when a lock factory is unable to get a lock.