AmazonDynamoDBLockClient (Amazon DynamoDB Lock Client 1.4.0 API)

java.lang.Object
- com.amazonaws.services.dynamodbv2.AmazonDynamoDBLockClient

All Implemented Interfaces:: Closeable, AutoCloseable, Runnable

@ThreadSafe
public class AmazonDynamoDBLockClient
extends Object
implements Runnable, Closeable

Provides a simple library for using DynamoDB's consistent read/write feature to use it for managing distributed locks.

In order to use this library, the client must create a table in DynamoDB, although the library provides a convenience method for creating that table (createLockTableInDynamoDB.)

Here is some example code for how to use the lock client for leader election to work on a resource called "database-3" (it assumes you already have a DynamoDB table named lockTable, which can be created with the static createLockTableInDynamoDB helper method):

 
  AmazonDynamoDBLockClient lockClient = new AmazonDynamoDBLockClient(
      AmazonDynamoDBLockClientOptions.builder(dynamoDBClient, "lockTable").build();
  try {
      // Attempt to acquire the lock indefinitely, polling DynamoDB every 2 seconds for the lock
      LockItem lockItem = lockClient.acquireLock(
          AcquireLockOptions.builder("database-3")
              .withRefreshPeriod(120L)
              .withAdditionalTimeToWaitForLock(Long.MAX_VALUE / 2L)
              .withTimeUnit(TimeUnit.MILLISECONDS)
              .build());
      if (!lockItem.isExpired()) {
          // do business logic, you can call lockItem.isExpired() to periodically check to make sure you still have the lock
          // the background thread will keep the lock valid for you by sending heartbeats (default is every 5 seconds)
      }
  } catch (LockNotGrantedException x) {
      // Should only be thrown if the lock could not be acquired for Long.MAX_VALUE / 2L milliseconds.
  }

Here is an example that involves a bunch of workers getting customer IDs from a queue, taking a lock on that Customer ID, then releasing that lock when complete:

 
  AmazonDynamoDBLockClient lockClient = new AmazonDynamoDBLockClient(
      AmazonDynamoDBLockClient.builder(dynamoDBClient, "lockTable").build();
  while (true) {
      // Somehow find out about what work needs to be done
      String customerID = getCustomerIDFromQueue();

     try {
          // Don't try indefinitely -- if someone else has a lock on this Customer ID, just move onto the next customer
          // (note that, if there is a lock on this customer ID, this method will still wait at least 20 seconds in order to be
          // able to determine
          // if that lock is stale)
          LockItem lockItem = lockClient.acquireLock(AcquireLockOptions.builder(customerID).build());
          if (!lockItem.isExpired()) {
              // Perform operation on this customer
          }
          lockItem.close();
      } catch (LockNotGrantedException x) {
          logger.info("We failed to acquire the lock for customer " + customerID, x);
      }
  }

Author:: Sasha Slutsker, Alexander Patrikalakis

Field Summary

Fields
Modifier and Type	Field and Description
`protected static String`	`ACQUIRE_LOCK_THAT_DOESNT_EXIST_PK_CONDITION`
`protected static String`	`ACQUIRE_LOCK_THAT_DOESNT_EXIST_PK_SK_CONDITION`
`protected static String`	`DATA`
`protected static String`	`DATA_PATH_EXPRESSION_VARIABLE`
`protected static String`	`DATA_VALUE_EXPRESSION_VARIABLE`
`protected software.amazon.awssdk.services.dynamodb.DynamoDbClient`	`dynamoDB`
`protected static String`	`IS_RELEASED`
`protected static software.amazon.awssdk.services.dynamodb.model.AttributeValue`	`IS_RELEASED_ATTRIBUTE_VALUE`
`protected static Boolean`	`IS_RELEASED_INDICATOR`
`protected static String`	`IS_RELEASED_PATH_EXPRESSION_VARIABLE`
`protected static String`	`IS_RELEASED_VALUE`
`protected static String`	`IS_RELEASED_VALUE_EXPRESSION_VARIABLE`
`protected static String`	`LEASE_DURATION`
`protected static String`	`LEASE_DURATION_PATH_VALUE_EXPRESSION_VARIABLE`
`protected static String`	`LEASE_DURATION_VALUE_EXPRESSION_VARIABLE`
`protected static AtomicInteger`	`lockClientId`
`protected static String`	`NEW_RVN_VALUE_EXPRESSION_VARIABLE`
`protected static String`	`OWNER_NAME`
`protected static String`	`OWNER_NAME_PATH_EXPRESSION_VARIABLE`
`protected static String`	`OWNER_NAME_VALUE_EXPRESSION_VARIABLE`
`protected static String`	`PK_EXISTS_AND_IS_RELEASED_CONDITION`
`protected static String`	`PK_EXISTS_AND_OWNER_NAME_SAME_AND_RVN_SAME_CONDITION`
`protected static String`	`PK_EXISTS_AND_RVN_IS_THE_SAME_AND_IS_RELEASED_CONDITION`
`protected static String`	`PK_EXISTS_AND_RVN_IS_THE_SAME_CONDITION`
`protected static String`	`PK_EXISTS_AND_SK_EXISTS_AND_IS_RELEASED_CONDITION`
`protected static String`	`PK_EXISTS_AND_SK_EXISTS_AND_OWNER_NAME_SAME_AND_RVN_SAME_CONDITION`
`protected static String`	`PK_EXISTS_AND_SK_EXISTS_AND_RVN_IS_THE_SAME_AND_IS_RELEASED_CONDITION`
`protected static String`	`PK_EXISTS_AND_SK_EXISTS_AND_RVN_IS_THE_SAME_CONDITION`
`protected static String`	`PK_PATH_EXPRESSION_VARIABLE`
`protected static String`	`PK_VALUE_EXPRESSION_VARIABLE`
`protected static String`	`QUERY_PK_EXPRESSION`
`protected static String`	`RECORD_VERSION_NUMBER`
`protected static String`	`REMOVE_IS_RELEASED_UPDATE_EXPRESSION`
`protected static String`	`RVN_PATH_EXPRESSION_VARIABLE`
`protected static String`	`RVN_VALUE_EXPRESSION_VARIABLE`
`protected static String`	`SK_PATH_EXPRESSION_VARIABLE`
`protected String`	`tableName`
`protected static String`	`UPDATE_IS_RELEASED`
`protected static String`	`UPDATE_IS_RELEASED_AND_DATA`
`protected static String`	`UPDATE_LEASE_DURATION_AND_RVN`
`protected static String`	`UPDATE_LEASE_DURATION_AND_RVN_AND_DATA`
`protected static String`	`UPDATE_LEASE_DURATION_AND_RVN_AND_REMOVE_DATA`

Constructor Summary

Constructors
Constructor and Description
`AmazonDynamoDBLockClient(AmazonDynamoDBLockClientOptions amazonDynamoDBLockClientOptions)` Initializes an AmazonDynamoDBLockClient using the lock client options specified in the AmazonDynamoDBLockClientOptions object.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`LockItem`	`acquireLock(AcquireLockOptions options)` Attempts to acquire a lock until it either acquires the lock, or a specified `additionalTimeToWaitForLock` is reached.
`void`	`assertLockTableExists()` Asserts that the lock table exists in DynamoDB.
`void`	`close()` Releases all of the locks by calling releaseAllLocks()
`static void`	`createLockTableInDynamoDB(CreateDynamoDBTableOptions createDynamoDBTableOptions)` Creates a DynamoDB table with the right schema for it to be used by this locking library.
`Stream<LockItem>`	`getAllLocksFromDynamoDB(boolean deleteOnRelease)` Retrieves all the lock items from DynamoDB.
`Optional<LockItem>`	`getLock(String key, Optional<String> sortKey)` Finds out who owns the given lock, but does not acquire the lock.
`Optional<LockItem>`	`getLockFromDynamoDB(GetLockOptions options)` Retrieves the lock item from DynamoDB.
`Stream<LockItem>`	`getLocksByPartitionKey(String key, boolean deleteOnRelease)` Retrieves the locks with partition_key = `key`.
`boolean`	`hasLock(String key, Optional<String> sortKey)` Returns true if the client currently owns the lock with @param key and @param sortKey.
`boolean`	`lockTableExists()` Checks whether the lock table exists in DynamoDB.
`boolean`	`releaseLock(LockItem lockItem)` Releases the given lock if the current user still has it, returning true if the lock was successfully released, and false if someone else already stole the lock.
`boolean`	`releaseLock(ReleaseLockOptions options)`
`void`	`run()` Loops forever, sending hearbeats for all the locks this thread needs to keep track of.
`void`	`sendHeartbeat(LockItem lockItem)` Sends a heartbeat to indicate that the given lock is still being worked on.
`void`	`sendHeartbeat(SendHeartbeatOptions options)` Sends a heartbeat to indicate that the given lock is still being worked on.
`Optional<LockItem>`	`tryAcquireLock(AcquireLockOptions options)` Attempts to acquire lock.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SK_PATH_EXPRESSION_VARIABLE
```
protected static final String SK_PATH_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - PK_PATH_EXPRESSION_VARIABLE
```
protected static final String PK_PATH_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - PK_VALUE_EXPRESSION_VARIABLE
```
protected static final String PK_VALUE_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - NEW_RVN_VALUE_EXPRESSION_VARIABLE
```
protected static final String NEW_RVN_VALUE_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - LEASE_DURATION_PATH_VALUE_EXPRESSION_VARIABLE
```
protected static final String LEASE_DURATION_PATH_VALUE_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - LEASE_DURATION_VALUE_EXPRESSION_VARIABLE
```
protected static final String LEASE_DURATION_VALUE_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - RVN_PATH_EXPRESSION_VARIABLE
```
protected static final String RVN_PATH_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - RVN_VALUE_EXPRESSION_VARIABLE
```
protected static final String RVN_VALUE_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - OWNER_NAME_PATH_EXPRESSION_VARIABLE
```
protected static final String OWNER_NAME_PATH_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - OWNER_NAME_VALUE_EXPRESSION_VARIABLE
```
protected static final String OWNER_NAME_VALUE_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - DATA_PATH_EXPRESSION_VARIABLE
```
protected static final String DATA_PATH_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - DATA_VALUE_EXPRESSION_VARIABLE
```
protected static final String DATA_VALUE_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - IS_RELEASED_PATH_EXPRESSION_VARIABLE
```
protected static final String IS_RELEASED_PATH_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - IS_RELEASED_VALUE_EXPRESSION_VARIABLE
```
protected static final String IS_RELEASED_VALUE_EXPRESSION_VARIABLE
```
    See Also:
    
    Constant Field Values
  - ACQUIRE_LOCK_THAT_DOESNT_EXIST_PK_CONDITION
```
protected static final String ACQUIRE_LOCK_THAT_DOESNT_EXIST_PK_CONDITION
```
  - ACQUIRE_LOCK_THAT_DOESNT_EXIST_PK_SK_CONDITION
```
protected static final String ACQUIRE_LOCK_THAT_DOESNT_EXIST_PK_SK_CONDITION
```
  - PK_EXISTS_AND_IS_RELEASED_CONDITION
```
protected static final String PK_EXISTS_AND_IS_RELEASED_CONDITION
```
  - PK_EXISTS_AND_SK_EXISTS_AND_IS_RELEASED_CONDITION
```
protected static final String PK_EXISTS_AND_SK_EXISTS_AND_IS_RELEASED_CONDITION
```
  - PK_EXISTS_AND_SK_EXISTS_AND_RVN_IS_THE_SAME_AND_IS_RELEASED_CONDITION
```
protected static final String PK_EXISTS_AND_SK_EXISTS_AND_RVN_IS_THE_SAME_AND_IS_RELEASED_CONDITION
```
  - PK_EXISTS_AND_SK_EXISTS_AND_RVN_IS_THE_SAME_CONDITION
```
protected static final String PK_EXISTS_AND_SK_EXISTS_AND_RVN_IS_THE_SAME_CONDITION
```
  - PK_EXISTS_AND_SK_EXISTS_AND_OWNER_NAME_SAME_AND_RVN_SAME_CONDITION
```
protected static final String PK_EXISTS_AND_SK_EXISTS_AND_OWNER_NAME_SAME_AND_RVN_SAME_CONDITION
```
  - PK_EXISTS_AND_RVN_IS_THE_SAME_AND_IS_RELEASED_CONDITION
```
protected static final String PK_EXISTS_AND_RVN_IS_THE_SAME_AND_IS_RELEASED_CONDITION
```
  - PK_EXISTS_AND_RVN_IS_THE_SAME_CONDITION
```
protected static final String PK_EXISTS_AND_RVN_IS_THE_SAME_CONDITION
```
  - PK_EXISTS_AND_OWNER_NAME_SAME_AND_RVN_SAME_CONDITION
```
protected static final String PK_EXISTS_AND_OWNER_NAME_SAME_AND_RVN_SAME_CONDITION
```
  - UPDATE_IS_RELEASED
```
protected static final String UPDATE_IS_RELEASED
```
  - UPDATE_IS_RELEASED_AND_DATA
```
protected static final String UPDATE_IS_RELEASED_AND_DATA
```
  - UPDATE_LEASE_DURATION_AND_RVN
```
protected static final String UPDATE_LEASE_DURATION_AND_RVN
```
  - UPDATE_LEASE_DURATION_AND_RVN_AND_REMOVE_DATA
```
protected static final String UPDATE_LEASE_DURATION_AND_RVN_AND_REMOVE_DATA
```
  - UPDATE_LEASE_DURATION_AND_RVN_AND_DATA
```
protected static final String UPDATE_LEASE_DURATION_AND_RVN_AND_DATA
```
  - REMOVE_IS_RELEASED_UPDATE_EXPRESSION
```
protected static final String REMOVE_IS_RELEASED_UPDATE_EXPRESSION
```
  - QUERY_PK_EXPRESSION
```
protected static final String QUERY_PK_EXPRESSION
```
  - dynamoDB
```
protected final software.amazon.awssdk.services.dynamodb.DynamoDbClient dynamoDB
```
  - tableName
```
protected final String tableName
```
  - DATA
```
protected static final String DATA
```
    See Also:
    
    Constant Field Values
  - OWNER_NAME
```
protected static final String OWNER_NAME
```
    See Also:
    
    Constant Field Values
  - LEASE_DURATION
```
protected static final String LEASE_DURATION
```
    See Also:
    
    Constant Field Values
  - RECORD_VERSION_NUMBER
```
protected static final String RECORD_VERSION_NUMBER
```
    See Also:
    
    Constant Field Values
  - IS_RELEASED
```
protected static final String IS_RELEASED
```
    See Also:
    
    Constant Field Values
  - IS_RELEASED_VALUE
```
protected static final String IS_RELEASED_VALUE
```
    See Also:
    
    Constant Field Values
  - IS_RELEASED_ATTRIBUTE_VALUE
```
protected static final software.amazon.awssdk.services.dynamodb.model.AttributeValue IS_RELEASED_ATTRIBUTE_VALUE
```
  - lockClientId
```
protected static volatile AtomicInteger lockClientId
```
  - IS_RELEASED_INDICATOR
```
protected static final Boolean IS_RELEASED_INDICATOR
```
- Constructor Detail
  - AmazonDynamoDBLockClient
```
public AmazonDynamoDBLockClient(AmazonDynamoDBLockClientOptions amazonDynamoDBLockClientOptions)
```
    Initializes an AmazonDynamoDBLockClient using the lock client options specified in the AmazonDynamoDBLockClientOptions object.
    
    Parameters:
    
    amazonDynamoDBLockClientOptions - The options to use when initializing the client, i.e. the table name, sort key value, etc.
- Method Detail
  - lockTableExists
```
public boolean lockTableExists()
```
    Checks whether the lock table exists in DynamoDB.
    
    Returns:
    
    true if the table exists, false otherwise.
  - assertLockTableExists
```
public void assertLockTableExists()
                           throws LockTableDoesNotExistException
```
    Asserts that the lock table exists in DynamoDB. You can use this method during application initialization to ensure that the lock client will be usable. Since this is a no-arg assertion as opposed to a check that returns a value, this method is also suitable as an init-method for a Spring bean.
    
    Throws:
    
    LockTableDoesNotExistException - if the table doesn't exist.
  - createLockTableInDynamoDB
```
public static void createLockTableInDynamoDB(CreateDynamoDBTableOptions createDynamoDBTableOptions)
```
    Creates a DynamoDB table with the right schema for it to be used by this locking library. The table should be set up in advance, because it takes a few minutes for DynamoDB to provision a new instance. Also, if the table already exists, this will throw an exception.
    This method lets you specify a sort key to be used by the lock client. This sort key then needs to be specified in the AmazonDynamoDBLockClientOptions when the lock client object is created.
    
    Parameters:
    
    createDynamoDBTableOptions - The options for the lock client
  - acquireLock
```
public LockItem acquireLock(AcquireLockOptions options)
                     throws LockNotGrantedException,
                            InterruptedException
```
    Attempts to acquire a lock until it either acquires the lock, or a specified additionalTimeToWaitForLock is reached. This method will poll DynamoDB based on the refreshPeriod. If it does not see the lock in DynamoDB, it will immediately return the lock to the caller. If it does see the lock, it will note the lease expiration on the lock. If the lock is deemed stale, (that is, there is no heartbeat on it for at least the length of its lease duration) then this will acquire and return it. Otherwise, if it waits for as long as additionalTimeToWaitForLock without acquiring the lock, then it will throw a LockNotGrantedException.
    
    Note that this method will wait for at least as long as the leaseDuration in order to acquire a lock that already exists. If the lock is not acquired in that time, it will wait an additional amount of time specified in additionalTimeToWaitForLock before giving up.
    
    See the defaults set when constructing a new AcquireLockOptions object for any fields that you do not set explicitly.
    
    Parameters:
    
    options - A combination of optional arguments that may be passed in for acquiring the lock
    
    Returns:
    
    the lock
    
    Throws:
    
    InterruptedException - in case the Thread.sleep call was interrupted while waiting to refresh.
    
    LockNotGrantedException
  - hasLock
```
public boolean hasLock(String key,
                       Optional<String> sortKey)
```
    Returns true if the client currently owns the lock with @param key and @param sortKey. It returns false otherwise.
    
    Parameters:
    
    key - The partition key representing the lock.
    
    sortKey - The sort key if present.
    
    Returns:
    
    true if the client owns the lock. It returns false otherwise.
  - tryAcquireLock
```
public Optional<LockItem> tryAcquireLock(AcquireLockOptions options)
                                  throws InterruptedException
```
    Attempts to acquire lock. If successful, returns the lock. Otherwise, returns Optional.empty(). For more details on behavior, please see acquireLock.
    
    Parameters:
    
    options - The options to use when acquiring the lock.
    
    Returns:
    
    the lock if successful.
    
    Throws:
    
    InterruptedException - in case this.acquireLock was interrupted.
  - releaseLock
```
public boolean releaseLock(LockItem lockItem)
```
    Releases the given lock if the current user still has it, returning true if the lock was successfully released, and false if someone else already stole the lock. Deletes the lock item if it is released and deleteLockItemOnClose is set.
    
    Parameters:
    
    lockItem - The lock item to release
    
    Returns:
    
    true if the lock is released, false otherwise
  - releaseLock
```
public boolean releaseLock(ReleaseLockOptions options)
```
  - getLock
```
public Optional<LockItem> getLock(String key,
                                  Optional<String> sortKey)
```
    Finds out who owns the given lock, but does not acquire the lock. It returns the metadata currently associated with the given lock. If the client currently has the lock, it will return the lock, and operations such as releaseLock will work. However, if the client does not have the lock, then operations like releaseLock will not work (after calling getLock, the caller should check lockItem.isExpired() to figure out if it currently has the lock.)
    
    Parameters:
    
    key - The partition key representing the lock.
    
    sortKey - The sort key if present.
    
    Returns:
    
    A LockItem that represents the lock, if the lock exists.
  - getLockFromDynamoDB
```
public Optional<LockItem> getLockFromDynamoDB(GetLockOptions options)
```
    Retrieves the lock item from DynamoDB. Note that this will return a LockItem even if it was released -- do NOT use this method if your goal is to acquire a lock for doing work.
    
    Parameters:
    
    options - The options such as the key, etc.
    
    Returns:
    
    The LockItem, or absent if it is not present. Note that the item can exist in the table even if it is released, as noted by isReleased().
  - getAllLocksFromDynamoDB
```
public Stream<LockItem> getAllLocksFromDynamoDB(boolean deleteOnRelease)
```
    Retrieves all the lock items from DynamoDB.
    
    Not that this will may return a lock item even if it was released.
    
    Parameters:
    
    deleteOnRelease - Whether or not the LockItem should delete the item when LockItem.close() is called on it.
    
    Returns:
    
    A non parallel Stream of all the LockItems in DynamoDB. Note that the item can exist in the table even if it is released, as noted by LockItem.isReleased().
  - getLocksByPartitionKey
```
public Stream<LockItem> getLocksByPartitionKey(String key,
                                               boolean deleteOnRelease)
```
    Retrieves the locks with partition_key = key.
    
    Not that this may return a lock item even if it was released.
    
    Parameters:
    
    key - the partition key
    
    deleteOnRelease - Whether or not the LockItem should delete the item when LockItem.close() is called on it.
    
    Returns:
    
    A non parallel Stream of LockItems that has the partition key in DynamoDB. Note that the item can exist in the table even if it is released, as noted by LockItem.isReleased().
  - sendHeartbeat
```
public void sendHeartbeat(LockItem lockItem)
```
    Sends a heartbeat to indicate that the given lock is still being worked on. If using createHeartbeatBackgroundThread=true when setting up this object, then this method is unnecessary, because the background thread will be periodically calling it and sending heartbeats. However, if createHeartbeatBackgroundThread=false, then this method must be called to instruct DynamoDB that the lock should not be expired.
    
    The lease duration of the lock will be set to the default specified in the constructor of this class.
    
    Parameters:
    
    lockItem - the lock item row to send a heartbeat and extend lock expiry.
  - sendHeartbeat
```
public void sendHeartbeat(SendHeartbeatOptions options)
```
    Sends a heartbeat to indicate that the given lock is still being worked on. If using createHeartbeatBackgroundThread=true when setting up this object, then this method is unnecessary, because the background thread will be periodically calling it and sending heartbeats. However, if createHeartbeatBackgroundThread=false, then this method must be called to instruct DynamoDB that the lock should not be expired.
    
    This method will also set the lease duration of the lock to the given value.
    
    This will also either update or delete the data from the lock, as specified in the options
    
    Parameters:
    
    options - a set of optional arguments for how to send the heartbeat
  - run
```
public void run()
```
    Loops forever, sending hearbeats for all the locks this thread needs to keep track of.
    
    Specified by:
    
    run in interface Runnable
  - close
```
public void close()
           throws IOException
```
    Releases all of the locks by calling releaseAllLocks()
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Throws:
    
    IOException

Class AmazonDynamoDBLockClient

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SK_PATH_EXPRESSION_VARIABLE

PK_PATH_EXPRESSION_VARIABLE

PK_VALUE_EXPRESSION_VARIABLE

NEW_RVN_VALUE_EXPRESSION_VARIABLE

LEASE_DURATION_PATH_VALUE_EXPRESSION_VARIABLE

LEASE_DURATION_VALUE_EXPRESSION_VARIABLE

RVN_PATH_EXPRESSION_VARIABLE

RVN_VALUE_EXPRESSION_VARIABLE

OWNER_NAME_PATH_EXPRESSION_VARIABLE

OWNER_NAME_VALUE_EXPRESSION_VARIABLE

DATA_PATH_EXPRESSION_VARIABLE

DATA_VALUE_EXPRESSION_VARIABLE

IS_RELEASED_PATH_EXPRESSION_VARIABLE

IS_RELEASED_VALUE_EXPRESSION_VARIABLE

ACQUIRE_LOCK_THAT_DOESNT_EXIST_PK_CONDITION

ACQUIRE_LOCK_THAT_DOESNT_EXIST_PK_SK_CONDITION

PK_EXISTS_AND_IS_RELEASED_CONDITION

PK_EXISTS_AND_SK_EXISTS_AND_IS_RELEASED_CONDITION

PK_EXISTS_AND_SK_EXISTS_AND_RVN_IS_THE_SAME_AND_IS_RELEASED_CONDITION

PK_EXISTS_AND_SK_EXISTS_AND_RVN_IS_THE_SAME_CONDITION

PK_EXISTS_AND_SK_EXISTS_AND_OWNER_NAME_SAME_AND_RVN_SAME_CONDITION

PK_EXISTS_AND_RVN_IS_THE_SAME_AND_IS_RELEASED_CONDITION

PK_EXISTS_AND_RVN_IS_THE_SAME_CONDITION

PK_EXISTS_AND_OWNER_NAME_SAME_AND_RVN_SAME_CONDITION

UPDATE_IS_RELEASED

UPDATE_IS_RELEASED_AND_DATA

UPDATE_LEASE_DURATION_AND_RVN

UPDATE_LEASE_DURATION_AND_RVN_AND_REMOVE_DATA

UPDATE_LEASE_DURATION_AND_RVN_AND_DATA

REMOVE_IS_RELEASED_UPDATE_EXPRESSION

QUERY_PK_EXPRESSION

dynamoDB

tableName

DATA

OWNER_NAME

LEASE_DURATION

RECORD_VERSION_NUMBER

IS_RELEASED

IS_RELEASED_VALUE

IS_RELEASED_ATTRIBUTE_VALUE

lockClientId

IS_RELEASED_INDICATOR

Constructor Detail

AmazonDynamoDBLockClient

Method Detail

lockTableExists

assertLockTableExists

createLockTableInDynamoDB

acquireLock

hasLock

tryAcquireLock

releaseLock

releaseLock

getLock

getLockFromDynamoDB

getAllLocksFromDynamoDB

getLocksByPartitionKey

sendHeartbeat

sendHeartbeat

run

close