Interface PerNodeLocalQueue
- All Known Implementing Classes:
TapePerNodeLocalQueue
,TapePerNodeLocalQueueWithStats
public interface PerNodeLocalQueue
Abstracts persistent queue implementation
A queue represents a FIFO queue of
CrossNodesEvent
for a specific node BambooNodeInfo
.
Each node may have from 1 to n queues. Each queue has a single processing (reading) process so
BambooClusterSettings.NUMBER_OF_PHYSICAL_QUEUES_UNDER_PER_NODE_QUEUE
i.e. the number of processes
for each node.
BambooClusterSettings.NUMBER_OF_PHYSICAL_QUEUES_UNDER_PER_NODE_QUEUE
is
the concurrency factor for communicating with a single remote node.
Example: if we have a cluster with 3 nodes (node1, node2, node3) on each node there will be
BambooClusterSettings.NUMBER_OF_PHYSICAL_QUEUES_UNDER_PER_NODE_QUEUE
queues for each of the "other" 2 remote nodes.- Since:
- 9.5
-
Nested Class Summary
Nested ClassesModifier and TypeInterfaceDescriptionstatic class
Uniquely identifies a queue -
Field Summary
Fields -
Method Summary
Modifier and TypeMethodDescriptionboolean
add
(CrossNodesEvent data) transactional add ofCrossNodesEvent
to the queue; when operation finished we "guarantee" that theCrossNodesEvent
is persistedvoid
backupQueue
(String prefix) Note: use with caution This method is mainly designed to handle critical state of the queue storage by backing up the current queue persistent store and recreating a new one.void
close()
closes the queue and all resources connected with this queue (like processing thread(s), files); closing a queue is definitive - it will never be open (i.e. not-closed) again;boolean
@NotNull PerNodeLocalQueue.QueueId
id()
boolean
isClosed()
Some operations (likeadd(CrossNodesEvent)
) on a closed queue will throw aIllegalStateException
.@NotNull String
name()
static int
nodeQueueNumber
(long threadId) Utility method to get the nodeQueueNumber for given thread id.static int
Utility method to get the nodeQueueNumber for current thread.@Nullable CrossNodesEvent
peek()
Allows to see what's on the head of the queue without removing it.void
remove()
RemoveCrossNodesEvent
from head of the queue.int
size()
@Nullable Long
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Field Details
-
NUMBER_OF_PHYSICAL_QUEUES_PER_NODE
static final int NUMBER_OF_PHYSICAL_QUEUES_PER_NODE
-
-
Method Details
-
close
void close()closes the queue and all resources connected with this queue (like processing thread(s), files); closing a queue is definitive - it will never be open (i.e. not-closed) again; -
isClosed
boolean isClosed()Some operations (likeadd(CrossNodesEvent)
) on a closed queue will throw aIllegalStateException
. This method allows to check if the queue has not been closed.- Returns:
- true if queue is closed
-
name
- Returns:
- name of the queue could be useful for the user, like identifying the queue file path from logs
-
id
- Returns:
- queue id which uniquely identifies this queue, i.e destination node and nodeQueueNumber, see
PerNodeLocalQueue.QueueId
-
add
transactional add ofCrossNodesEvent
to the queue; when operation finished we "guarantee" that theCrossNodesEvent
is persisted- Parameters:
data
-- Returns:
- true if message was added or false if dropped (like exceeding queue size limit)
- Throws:
IllegalStateException
- when queue is closed
-
peek
Allows to see what's on the head of the queue without removing it.- Returns:
- crossNodesEvent from queue head or null when queue is empty.
- Throws:
IllegalStateException
- when queue is closed
-
remove
RemoveCrossNodesEvent
from head of the queue.- Throws:
NoSuchElementException
- when doing a remove on an empty queueIllegalStateException
- when queue is closed
-
getQueueFilePath
- Returns:
- the queue file path if exists, empty otherwise
-
hasPermission
boolean hasPermission()- Returns:
- true if it has read/write access to queue storage
-
usableSpaceInBytes
- Returns:
- number of bytes left on device where this queue is stored or null if unable to get this value
-
size
int size()- Returns:
- number of elements in this queue
-
backupQueue
Note: use with caution This method is mainly designed to handle critical state of the queue storage by backing up the current queue persistent store and recreating a new one. Renames current queue file name to [prefix]_[queue_file_name] and re-creates queue file with [queue_file_name]. If file with [prefix]_[queue_file_name] already exists it will be deleted. Note that ifbackupQueue(String)
is called betweenpeek()
andremove()
this can causeremove()
to delete a differentCrossNodesEvent
then expected or may throwNoSuchElementException
if the new queue afterbackupQueue(String)
is empty.- Throws:
IOException
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nodeQueueNumberForCurrentThread
static int nodeQueueNumberForCurrentThread()Utility method to get the nodeQueueNumber for current thread.- Returns:
- nodeQueueNumber for current thread
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nodeQueueNumber
static int nodeQueueNumber(long threadId) Utility method to get the nodeQueueNumber for given thread id.- Returns:
- nodeQueueNumber for given thread id
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