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Last transform of pipeline hangs #11

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Open
Last transform of pipeline hangs#11

Description

@br4in1
br4in1
opened on Jul 27, 2021

Hello there,

I'm working on a project where I have a pipeline (one readable stream as the source and multiple Transforms).
In normal circumstances, everything works fine. But it is when a huge amount of data enters the pipeline in rapid succession that things get strange (the problem appears with at least 4000 chunks but I guess that's irrelevant):
The pipeline hangs after processing a small portion of the data, and this continues forever. It doesn't even resume.

By adding log and investigating the problem, I came to the conclusion that it is always the last Transform that hangs. And to be sure, I deleted the last Transform (so now, the n-1 Transform is the last one in the pipeline) and it is, then, the new last Transform that hangs.

I thought that it is a memory problem and so I tried some workarounds:

  • I increased the highWaterMark threshold, but this didn't completely solve the issue, though it delayed it (the pipeline processes more data but still hangs at some point).
  • I increased/decreased the parallelism option for each Transform and this didn't solve it either.

At that point, I decided to simplify my pipeline to get to some sort of a skeleton model. It turned out that the ordered option is causing the problem when set to false.

Valid workaround

I thought that it is maybe one of the Transforms is being corked at some point. So I added a data event listener for each one to uncork manually if this is the case. It worked. But then I tried, for no valid reason, to leave the callback of the listener empty (not trying to uncork) and it still works.
So, long story short : adding an empty listener on the Transform fixes the hanging problem (code chunk below)

return transform(myParallelism, { ordered: false }, async (data: Input, callback: TransformCallback) => {
try {
const result = await someAsyncOperation(data)
callback(null, result)
} catch (error) {
callback(error)
}
}).on('data', () => {
})

I'm not really sure, though, if the real problem comes for this library or from the implementation of node streams.
Also I don't have a minimal code to show the problem, but I can work on one if deemed necessary.

Thank you so much 😁

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Last transform of pipeline hangs · Issue #11 · mafintosh/parallel-transform · GitHub
      Skip to content
      Last transform of pipeline hangs #11
      Open
      Open
      Last transform of pipeline hangs#11
      Description
      @br4in1
      br4in1
      opened on Jul 27, 2021
      Hello there,
      I'm working on a project where I have a pipeline (one readable stream as the source and multiple Transforms).
      
In normal circumstances, everything works fine. But it is when a huge amount of data enters the pipeline in rapid succession that things get strange (the problem appears with at least 4000 chunks but I guess that's irrelevant):
      
The pipeline hangs after processing a small portion of the data, and this continues forever. It doesn't even resume.
      By adding log and investigating the problem, I came to the conclusion that it is always the last Transform that hangs. And to be sure, I deleted the last Transform (so now, the n-1 Transform is the last one in the pipeline) and it is, then, the new last Transform that hangs.
      I thought that it is a memory problem and so I tried some workarounds:
      • I increased the highWaterMark threshold, but this didn't completely solve the issue, though it delayed it (the pipeline processes more data but still hangs at some point).
      • I increased/decreased the parallelism option for each Transform and this didn't solve it either.
      At that point, I decided to simplify my pipeline to get to some sort of a skeleton model. It turned out that the ordered option is causing the problem when set to false.
      Valid workaround
      I thought that it is maybe one of the Transforms is being corked at some point. So I added a data event listener for each one to uncork manually if this is the case. It worked. But then I tried, for no valid reason, to leave the callback of the listener empty (not trying to uncork) and it still works.
      
So, long story short : adding an empty listener on the Transform fixes the hanging problem (code chunk below)
      return transform(myParallelism, { ordered: false }, async (data: Input, callback: TransformCallback) => {
try {
const result = await someAsyncOperation(data)
callback(null, result)
} catch (error) {
callback(error)
}
}).on('data', () => {
})

      I'm not really sure, though, if the real problem comes for this library or from the implementation of node streams.
      
Also I don't have a minimal code to show the problem, but I can work on one if deemed necessary.
      Thank you so much 😁
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Last transform of pipeline hangs · Issue #11 · mafintosh/parallel-transform · GitHub
          Skip to content
          Last transform of pipeline hangs #11
          Open
          Open
          Last transform of pipeline hangs#11
          Description
          @br4in1
          br4in1
          opened on Jul 27, 2021
          Hello there,
          I'm working on a project where I have a pipeline (one readable stream as the source and multiple Transforms).
          
In normal circumstances, everything works fine. But it is when a huge amount of data enters the pipeline in rapid succession that things get strange (the problem appears with at least 4000 chunks but I guess that's irrelevant):
          
The pipeline hangs after processing a small portion of the data, and this continues forever. It doesn't even resume.
          By adding log and investigating the problem, I came to the conclusion that it is always the last Transform that hangs. And to be sure, I deleted the last Transform (so now, the n-1 Transform is the last one in the pipeline) and it is, then, the new last Transform that hangs.
          I thought that it is a memory problem and so I tried some workarounds:
          • I increased the highWaterMark threshold, but this didn't completely solve the issue, though it delayed it (the pipeline processes more data but still hangs at some point).
          • I increased/decreased the parallelism option for each Transform and this didn't solve it either.
          At that point, I decided to simplify my pipeline to get to some sort of a skeleton model. It turned out that the ordered option is causing the problem when set to false.
          Valid workaround
          I thought that it is maybe one of the Transforms is being corked at some point. So I added a data event listener for each one to uncork manually if this is the case. It worked. But then I tried, for no valid reason, to leave the callback of the listener empty (not trying to uncork) and it still works.
          
So, long story short : adding an empty listener on the Transform fixes the hanging problem (code chunk below)
          return transform(myParallelism, { ordered: false }, async (data: Input, callback: TransformCallback) => {
try {
const result = await someAsyncOperation(data)
callback(null, result)
} catch (error) {
callback(error)
}
}).on('data', () => {
})

          I'm not really sure, though, if the real problem comes for this library or from the implementation of node streams.
          
Also I don't have a minimal code to show the problem, but I can work on one if deemed necessary.
          Thank you so much 😁
          Metadata
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Last transform of pipeline hangs · Issue #11 · mafintosh/parallel-transform · GitHub
              Skip to content
              Last transform of pipeline hangs #11
              Open
              Open
              Last transform of pipeline hangs#11
              Description
              @br4in1
              br4in1
              opened on Jul 27, 2021
              Hello there,
              I'm working on a project where I have a pipeline (one readable stream as the source and multiple Transforms).
              
In normal circumstances, everything works fine. But it is when a huge amount of data enters the pipeline in rapid succession that things get strange (the problem appears with at least 4000 chunks but I guess that's irrelevant):
              
The pipeline hangs after processing a small portion of the data, and this continues forever. It doesn't even resume.
              By adding log and investigating the problem, I came to the conclusion that it is always the last Transform that hangs. And to be sure, I deleted the last Transform (so now, the n-1 Transform is the last one in the pipeline) and it is, then, the new last Transform that hangs.
              I thought that it is a memory problem and so I tried some workarounds:
              • I increased the highWaterMark threshold, but this didn't completely solve the issue, though it delayed it (the pipeline processes more data but still hangs at some point).
              • I increased/decreased the parallelism option for each Transform and this didn't solve it either.
              At that point, I decided to simplify my pipeline to get to some sort of a skeleton model. It turned out that the ordered option is causing the problem when set to false.
              Valid workaround
              I thought that it is maybe one of the Transforms is being corked at some point. So I added a data event listener for each one to uncork manually if this is the case. It worked. But then I tried, for no valid reason, to leave the callback of the listener empty (not trying to uncork) and it still works.
              
So, long story short : adding an empty listener on the Transform fixes the hanging problem (code chunk below)
              return transform(myParallelism, { ordered: false }, async (data: Input, callback: TransformCallback) => {
try {
const result = await someAsyncOperation(data)
callback(null, result)
} catch (error) {
callback(error)
}
}).on('data', () => {
})

              I'm not really sure, though, if the real problem comes for this library or from the implementation of node streams.
              
Also I don't have a minimal code to show the problem, but I can work on one if deemed necessary.
              Thank you so much 😁
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Last transform of pipeline hangs · Issue #11 · mafintosh/parallel-transform · GitHub
                  Skip to content
                  Last transform of pipeline hangs #11
                  Open
                  Open
                  Last transform of pipeline hangs#11
                  Description
                  @br4in1
                  br4in1
                  opened on Jul 27, 2021
                  Hello there,
                  I'm working on a project where I have a pipeline (one readable stream as the source and multiple Transforms).
                  
In normal circumstances, everything works fine. But it is when a huge amount of data enters the pipeline in rapid succession that things get strange (the problem appears with at least 4000 chunks but I guess that's irrelevant):
                  
The pipeline hangs after processing a small portion of the data, and this continues forever. It doesn't even resume.
                  By adding log and investigating the problem, I came to the conclusion that it is always the last Transform that hangs. And to be sure, I deleted the last Transform (so now, the n-1 Transform is the last one in the pipeline) and it is, then, the new last Transform that hangs.
                  I thought that it is a memory problem and so I tried some workarounds:
                  • I increased the highWaterMark threshold, but this didn't completely solve the issue, though it delayed it (the pipeline processes more data but still hangs at some point).
                  • I increased/decreased the parallelism option for each Transform and this didn't solve it either.
                  At that point, I decided to simplify my pipeline to get to some sort of a skeleton model. It turned out that the ordered option is causing the problem when set to false.
                  Valid workaround
                  I thought that it is maybe one of the Transforms is being corked at some point. So I added a data event listener for each one to uncork manually if this is the case. It worked. But then I tried, for no valid reason, to leave the callback of the listener empty (not trying to uncork) and it still works.
                  
So, long story short : adding an empty listener on the Transform fixes the hanging problem (code chunk below)
                  return transform(myParallelism, { ordered: false }, async (data: Input, callback: TransformCallback) => {
try {
const result = await someAsyncOperation(data)
callback(null, result)
} catch (error) {
callback(error)
}
}).on('data', () => {
})

                  I'm not really sure, though, if the real problem comes for this library or from the implementation of node streams.
                  
Also I don't have a minimal code to show the problem, but I can work on one if deemed necessary.
                  Thank you so much 😁
                  Metadata
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var __m = "*";
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Last transform of pipeline hangs · Issue #11 · mafintosh/parallel-transform · GitHub
                      Skip to content
                      Last transform of pipeline hangs #11
                      Open
                      Open
                      Last transform of pipeline hangs#11
                      Description
                      @br4in1
                      br4in1
                      opened on Jul 27, 2021
                      Hello there,
                      I'm working on a project where I have a pipeline (one readable stream as the source and multiple Transforms).
                      
In normal circumstances, everything works fine. But it is when a huge amount of data enters the pipeline in rapid succession that things get strange (the problem appears with at least 4000 chunks but I guess that's irrelevant):
                      
The pipeline hangs after processing a small portion of the data, and this continues forever. It doesn't even resume.
                      By adding log and investigating the problem, I came to the conclusion that it is always the last Transform that hangs. And to be sure, I deleted the last Transform (so now, the n-1 Transform is the last one in the pipeline) and it is, then, the new last Transform that hangs.
                      I thought that it is a memory problem and so I tried some workarounds:
                      • I increased the highWaterMark threshold, but this didn't completely solve the issue, though it delayed it (the pipeline processes more data but still hangs at some point).
                      • I increased/decreased the parallelism option for each Transform and this didn't solve it either.
                      At that point, I decided to simplify my pipeline to get to some sort of a skeleton model. It turned out that the ordered option is causing the problem when set to false.
                      Valid workaround
                      I thought that it is maybe one of the Transforms is being corked at some point. So I added a data event listener for each one to uncork manually if this is the case. It worked. But then I tried, for no valid reason, to leave the callback of the listener empty (not trying to uncork) and it still works.
                      
So, long story short : adding an empty listener on the Transform fixes the hanging problem (code chunk below)
                      return transform(myParallelism, { ordered: false }, async (data: Input, callback: TransformCallback) => {
try {
const result = await someAsyncOperation(data)
callback(null, result)
} catch (error) {
callback(error)
}
}).on('data', () => {
})

                      I'm not really sure, though, if the real problem comes for this library or from the implementation of node streams.
                      
Also I don't have a minimal code to show the problem, but I can work on one if deemed necessary.
                      Thank you so much 😁
                      Metadata
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Last transform of pipeline hangs · Issue #11 · mafintosh/parallel-transform · GitHub
                          Skip to content
                          Last transform of pipeline hangs #11
                          Open
                          Open
                          Last transform of pipeline hangs#11
                          Description
                          @br4in1
                          br4in1
                          opened on Jul 27, 2021
                          Hello there,
                          I'm working on a project where I have a pipeline (one readable stream as the source and multiple Transforms).
                          
In normal circumstances, everything works fine. But it is when a huge amount of data enters the pipeline in rapid succession that things get strange (the problem appears with at least 4000 chunks but I guess that's irrelevant):
                          
The pipeline hangs after processing a small portion of the data, and this continues forever. It doesn't even resume.
                          By adding log and investigating the problem, I came to the conclusion that it is always the last Transform that hangs. And to be sure, I deleted the last Transform (so now, the n-1 Transform is the last one in the pipeline) and it is, then, the new last Transform that hangs.
                          I thought that it is a memory problem and so I tried some workarounds:
                          • I increased the highWaterMark threshold, but this didn't completely solve the issue, though it delayed it (the pipeline processes more data but still hangs at some point).
                          • I increased/decreased the parallelism option for each Transform and this didn't solve it either.
                          At that point, I decided to simplify my pipeline to get to some sort of a skeleton model. It turned out that the ordered option is causing the problem when set to false.
                          Valid workaround
                          I thought that it is maybe one of the Transforms is being corked at some point. So I added a data event listener for each one to uncork manually if this is the case. It worked. But then I tried, for no valid reason, to leave the callback of the listener empty (not trying to uncork) and it still works.
                          
So, long story short : adding an empty listener on the Transform fixes the hanging problem (code chunk below)
                          return transform(myParallelism, { ordered: false }, async (data: Input, callback: TransformCallback) => {
try {
const result = await someAsyncOperation(data)
callback(null, result)
} catch (error) {
callback(error)
}
}).on('data', () => {
})

                          I'm not really sure, though, if the real problem comes for this library or from the implementation of node streams.
                          
Also I don't have a minimal code to show the problem, but I can work on one if deemed necessary.
                          Thank you so much 😁
                          Metadata
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                              No branches or pull requests
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Last transform of pipeline hangs · Issue #11 · mafintosh/parallel-transform · GitHub
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                              Last transform of pipeline hangs #11
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                              Last transform of pipeline hangs#11
                              Description
                              @br4in1
                              br4in1
                              opened on Jul 27, 2021
                              Hello there,
                              I'm working on a project where I have a pipeline (one readable stream as the source and multiple Transforms).
                              
In normal circumstances, everything works fine. But it is when a huge amount of data enters the pipeline in rapid succession that things get strange (the problem appears with at least 4000 chunks but I guess that's irrelevant):
                              
The pipeline hangs after processing a small portion of the data, and this continues forever. It doesn't even resume.
                              By adding log and investigating the problem, I came to the conclusion that it is always the last Transform that hangs. And to be sure, I deleted the last Transform (so now, the n-1 Transform is the last one in the pipeline) and it is, then, the new last Transform that hangs.
                              I thought that it is a memory problem and so I tried some workarounds:
                              • I increased the highWaterMark threshold, but this didn't completely solve the issue, though it delayed it (the pipeline processes more data but still hangs at some point).
                              • I increased/decreased the parallelism option for each Transform and this didn't solve it either.
                              At that point, I decided to simplify my pipeline to get to some sort of a skeleton model. It turned out that the ordered option is causing the problem when set to false.
                              Valid workaround
                              I thought that it is maybe one of the Transforms is being corked at some point. So I added a data event listener for each one to uncork manually if this is the case. It worked. But then I tried, for no valid reason, to leave the callback of the listener empty (not trying to uncork) and it still works.
                              
So, long story short : adding an empty listener on the Transform fixes the hanging problem (code chunk below)
                              return transform(myParallelism, { ordered: false }, async (data: Input, callback: TransformCallback) => {
try {
const result = await someAsyncOperation(data)
callback(null, result)
} catch (error) {
callback(error)
}
}).on('data', () => {
})

                              I'm not really sure, though, if the real problem comes for this library or from the implementation of node streams.
                              
Also I don't have a minimal code to show the problem, but I can work on one if deemed necessary.
                              Thank you so much 😁
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