Interface IDataStreamer<TK, TV>
Data streamer loads data efficiently into cache. Updates are buffered and mapped to primary nodes to ensure minimal data movement and optimal resource utilization.
Note that streamer loads data to remote nodes in parallel, so cache updates can be reordered.
Also note that IDataStreamer is not the only way to load data into cache.
Alternatively you can use
LoadCache(Action<TK, TV>, Object[])
method to load data from underlying data store. You can also use standard cache
put and putAll operations as well, but they most likely will not perform
as well as this class for loading data. And finally, data can be loaded from underlying
data store on demand, whenever it is accessed - for this no explicit data loading step
is needed.
IDataStreamer supports the following configuration properties:
- PerNodeBufferSizeWhen entries are added to data streamer they are not sent to Ignite right away and are buffered internally for better performance and network utilization. This setting controls the size of internal per-node buffer before buffered data is sent to remote node. Default value is 1024.
- PerThreadBufferSizeWhen entries are added to data streamer they are not sent to Ignite right away and are buffered internally on per thread basis for better performance and network utilization. This setting controls the size of internal per-thread buffer before buffered data is sent to remote node. Default value is 4096.
- PerNodeParallelOperationsSometimes data may be added to the data streamer faster than it can be put in cache. In this case, new buffered load messages are sent to remote nodes before responses from previous ones are received. This could cause unlimited heap memory utilization growth on local and remote nodes. To control memory utilization, this setting limits maximum allowed number of parallel buffered load messages that are being processed on remote nodes. If this number is exceeded, then data streamer add/remove methods will block to control memory utilization. Default value is 16.
- AutoFlushFrequencyAutomatic flush frequency in milliseconds. Essentially, this is the time
after which the streamer will make an attempt to submit all data added so far to remote
nodes. Note that there is no guarantee that data will be delivered after this concrete
attempt (e.g., it can fail when topology is changing), but it won't be lost anyway.
Disabled by default (default value is
0). - IsolatedDefines if data streamer will assume that there are no other concurrent
updates and allow data streamer choose most optimal concurrent implementation. Default value
is
false.
All members are thread-safe and may be used concurrently from multiple threads.
Namespace: Apache.Ignite.Core.Datastream
Assembly: Apache.Ignite.Core.dll
Syntax
public interface IDataStreamer<TK, TV> : IDisposable
Type Parameters
| Name | Description |
|---|---|
| TK | |
| TV |
Properties
AllowOverwrite
Gets or sets a value indicating whether existing values can be overwritten by the data streamer. Performance is better when this flag is false.
NOTE: When false, cache updates won't be propagated to cache store (even if SkipStore is false).
Default is false.
Declaration
bool AllowOverwrite { get; set; }
Property Value
| Type | Description |
|---|---|
| System.Boolean |
AutoFlushFrequency
Gets or sets the automatic flush frequency, in milliseconds. Data streamer buffers the data for performance reasons. The buffer is flushed in the following cases:
- Buffer is full.
- Flush() or TryFlush() is called.
- Periodically when AutoFlushInterval is set.
If set to 0, automatic flush is disabled.
Default is 0 (disabled).
Declaration
long AutoFlushFrequency { get; set; }
Property Value
| Type | Description |
|---|---|
| System.Int64 |
AutoFlushInterval
Gets or sets the automatic flush interval. Data streamer buffers the data for performance reasons. The buffer is flushed in the following cases:
- Buffer is full.
- Flush() or TryFlush() is called.
- Periodically when AutoFlushInterval is set.
When set to
Default is
Declaration
TimeSpan AutoFlushInterval { get; set; }
Property Value
| Type | Description |
|---|---|
| TimeSpan |
CacheName
Name of the cache to load data to.
Declaration
string CacheName { get; }
Property Value
| Type | Description |
|---|---|
| System.String |
PerNodeBufferSize
Size of per node key-value pairs buffer.
Setter must be called before any add/remove operation.
Default is DefaultPerNodeBufferSize.
Declaration
int PerNodeBufferSize { get; set; }
Property Value
| Type | Description |
|---|---|
| System.Int32 |
PerNodeParallelOperations
Maximum number of parallel load operations for a single node.
Setter must be called before any add/remove operation.
Default is 0, which means Ignite calculates this automatically as DataStreamerThreadPoolSize * DefaultParallelOperationsMultiplier.
Declaration
int PerNodeParallelOperations { get; set; }
Property Value
| Type | Description |
|---|---|
| System.Int32 |
PerThreadBufferSize
Size of per thread key-value pairs buffer.
Setter must be called before any add/remove operation.
Default is DefaultPerThreadBufferSize.
Declaration
int PerThreadBufferSize { get; set; }
Property Value
| Type | Description |
|---|---|
| System.Int32 |
Receiver
Gets or sets custom stream receiver.
Declaration
IStreamReceiver<TK, TV> Receiver { get; set; }
Property Value
| Type | Description |
|---|---|
| IStreamReceiver<TK, TV> |
SkipStore
Flag indicating that write-through behavior should be disabled for data loading.
AllowOverwrite must be true for write-through to work.
Default is false.
Declaration
bool SkipStore { get; set; }
Property Value
| Type | Description |
|---|---|
| System.Boolean |
Task
Gets the task for this loading process. This task completes whenever method Close(Boolean) completes.
Declaration
Task Task { get; }
Property Value
| Type | Description |
|---|---|
| Task |
Timeout
Gets or sets the timeout. Negative values mean no timeout. Default is DefaultTimeout.
Timeout is used in the following cases:
Declaration
TimeSpan Timeout { get; set; }
Property Value
| Type | Description |
|---|---|
| TimeSpan |
Methods
Add(TK, TV)
Adds single key-value pair for loading. Passing null as value will be
interpreted as removal.
Declaration
void Add(TK key, TV val)
Parameters
| Type | Name | Description |
|---|---|---|
| TK | key | Key. |
| TV | val | Value. |
Add(ICollection<KeyValuePair<TK, TV>>)
Adds collection of key-value pairs for loading.
Declaration
void Add(ICollection<KeyValuePair<TK, TV>> entries)
Parameters
| Type | Name | Description |
|---|---|---|
| ICollection<KeyValuePair<TK, TV>> | entries | Entries. |
Add(KeyValuePair<TK, TV>)
Adds single key-value pair for loading. Passing null as pair's value will
be interpreted as removal.
Declaration
void Add(KeyValuePair<TK, TV> pair)
Parameters
| Type | Name | Description |
|---|---|---|
| KeyValuePair<TK, TV> | pair | Key-value pair. |
AddData(TK, TV)
Adds single key-value pair for loading. Passing null as value will be
interpreted as removal.
Declaration
Task AddData(TK key, TV val)
Parameters
| Type | Name | Description |
|---|---|---|
| TK | key | Key. |
| TV | val | Value. |
Returns
| Type | Description |
|---|---|
| Task | Task for this operation. |
AddData(ICollection<KeyValuePair<TK, TV>>)
Adds collection of key-value pairs for loading.
Declaration
Task AddData(ICollection<KeyValuePair<TK, TV>> entries)
Parameters
| Type | Name | Description |
|---|---|---|
| ICollection<KeyValuePair<TK, TV>> | entries | Entries. |
Returns
| Type | Description |
|---|---|
| Task | Task for this operation. |
AddData(KeyValuePair<TK, TV>)
Adds single key-value pair for loading. Passing null as pair's value will
be interpreted as removal.
Declaration
Task AddData(KeyValuePair<TK, TV> pair)
Parameters
| Type | Name | Description |
|---|---|---|
| KeyValuePair<TK, TV> | pair | Key-value pair. |
Returns
| Type | Description |
|---|---|
| Task | Task for this operation. |
Close(Boolean)
Closes this streamer, optionally loading any remaining data into the cache.
Declaration
void Close(bool cancel)
Parameters
| Type | Name | Description |
|---|---|---|
| System.Boolean | cancel | Whether to cancel ongoing loading operations. When set to |
Flush()
Loads any remaining buffered data, but doesn't close the streamer.
Declaration
void Flush()
FlushAsync()
Loads any remaining buffered data, but doesn't close the streamer.
Declaration
Task FlushAsync()
Returns
| Type | Description |
|---|---|
| Task |
GetCurrentBatchTask()
Gets the task for the current batch. This task completes when current and all previous batches are flushed, either explicitly with Flush(), or automatically when the buffer is full or AutoFlushFrequency is set.
Declaration
Task GetCurrentBatchTask()
Returns
| Type | Description |
|---|---|
| Task |
Remove(TK)
Adds key for removal.
Declaration
void Remove(TK key)
Parameters
| Type | Name | Description |
|---|---|---|
| TK | key | Key. |
RemoveData(TK)
Adds key for removal.
Declaration
Task RemoveData(TK key)
Parameters
| Type | Name | Description |
|---|---|---|
| TK | key | Key. |
Returns
| Type | Description |
|---|---|
| Task | Task for this operation. |
TryFlush()
Makes an attempt to load remaining data. This method is mostly similar to Flush() with the difference that it won't wait and will exit immediately.
Declaration
void TryFlush()
WithKeepBinary<TK1, TV1>()
Gets streamer instance with binary mode enabled, changing key and/or value types if necessary.
In binary mode stream receiver gets data in binary format.
You can only change key/value types when transitioning from non-binary to binary streamer;
Changing type of binary streamer is not allowed and will throw an
Declaration
IDataStreamer<TK1, TV1> WithKeepBinary<TK1, TV1>()
Returns
| Type | Description |
|---|---|
| IDataStreamer<TK1, TV1> | Streamer instance with binary mode enabled. |
Type Parameters
| Name | Description |
|---|---|
| TK1 | Key type in binary mode. |
| TV1 | Value type in binary mode. |