I Would Like To Chain Multiple Mapreduce Jobs In Google App Engine In Python

Caveat: I am new to Google App Engine and Python, but I have managed to implement a PageRank algorithm in Google App Engine so far. Next, I would like to chain together three mapre

Solution 1:

A pipeline argument can be a concrete value or a PipelineFutures (and in that case it will wait until the future's value is available). In your case you are passing a PipelineFutures as a parameter to a concrete value (BlobKeys). Instead try yielding BlobKeys(output1) and passing its result as a parameter to the next pipeline. e.g: output1_1 = yield BlobKeys(output1) output2 = yield mapreduce_pipeline.MapreducePipeline(..., mapper_params=output1_1,...)