IMap.getAsync(Object)or any other asynchronous call. The main purpose of the pipeline is to control the number of concurrent requests when using asynchronous invocations. This can be done by setting the depth using the constructor. So you could set the depth to e.g 100 and do 1000 calls. That means that at any given moment, there will only be 100 concurrent requests. It depends on the situation what the optimal depth (number of invocations in flight) should be. If it is too high, you can run into memory related problems. If it is too low, it will provide little or no performance advantage at all. In most cases a pipeline and a few hundred map/cache puts/gets should not lead to any problems. For testing purposes we frequently have a pipeline of 1000 or more concurrent requests to be able to saturate the system. The Pipeline can't be used for transaction purposes. So you can't create a Pipeline, add a set of asynchronous request and then not call
results()to prevent executing these requests. Invocations can be executed before the
results()is called. Pipelines can be used by both clients or members. The Pipeline isn't threadsafe. So only a single thread should add requests to the pipeline and wait for results. Currently all
ICompletableFutureand their responses are stored in the Pipeline. So be careful executing a huge number of request with a single pipeline because it can lead to a huge memory bubble. In this cases it is better to periodically, after waiting for completion, to replace the pipeline by a new one. In the future we might provide this as an out of the box experience, but currently we do not. A pipeline provides its own backpressure on the system. So there will not be more in flight invocations than the depth of the pipeline. This means that the pipeline will work fine when backpressure on the client/member is disabled (default). Also when it it enabled it will work fine, but keep in mind that the number of concurrent invocations in the pipeline could be lower than the configured number of invocation of the pipeline because the backpressure on the client/member is leading. The Pipeline has been marked as Beta since we need to see how the API needs to evolve. But there is no problem using it in production. We use similar techniques to achieve high performance.
|Constructor and Description|
Creates a pipeline with the given depth.
|Modifier and Type||Method and Description|
Adds a future to this Pipeline or blocks until there is capacity to add the future to the pipeline.
Returns the results.
public Pipeline(int depth)
depth- the maximum number of concurrent calls allowed in this pipeline.
IllegalArgumentException- if depth smaller than 1. But if you use depth 1, it means that every call is sync and you will not benefit from pipelining at all.
The results are returned in the order the requests were done.
This call waits till all requests have completed.
Exception- is something fails getting the results.
public ICompletableFuture<E> add(ICompletableFuture<E> future) throws InterruptedException
This call blocks until there is space in the pipeline, but it doesn't mean that the invocation that returned the ICompletableFuture got blocked.
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