dataflow

问题 I have code of the following form: class Test { private final A t; public Test() { for ( ... : ... ) { final A u = null; } t = new A(); } private class A {} } Compiler says: variable t might already have been assigned Interestingly, if I perform any of the following changes to the loop it works out! Change the loop's content to A u = null Remove the loop (but keep final A u = null; ) Replace the foreach-style loop with a classic counting loop What is going on here? Note: I could not get the

问题 I have code of the following form: class Test { private final A t; public Test() { for ( ... : ... ) { final A u = null; } t = new A(); } private class A {} } Compiler says: variable t might already have been assigned Interestingly, if I perform any of the following changes to the loop it works out! Change the loop's content to A u = null Remove the loop (but keep final A u = null; ) Replace the foreach-style loop with a classic counting loop What is going on here? Note: I could not get the

问题 I'm using the textbook "VHDL: Programming By Example" by Douglas L Perry, Fourth Edition. He gave an example of the Dataflow programming model in page 4: Code I: ENTITY mux IS PORT ( a, b, c, d : IN BIT; s0, s1 : IN BIT; x, : OUT BIT); END mux; ARCHITECTURE dataflow OF mux IS SIGNAL select : INTEGER; BEGIN select <= 0 WHEN s0 = ‘0’ AND s1 = ‘0’ ELSE 1 WHEN s0 = ‘1’ AND s1 = ‘0’ ELSE 2 WHEN s0 = ‘0’ AND s1 = ‘1’ ELSE 3; x <= a AFTER 0.5 NS WHEN select = 0 ELSE b AFTER 0.5 NS WHEN select = 1

问题 I have a Beam pipeline that starts off with reading multiple text files where each line in a file represents a row that gets inserted into Bigtable later in the pipeline. The scenario requires confirming that the count of rows extracted from each file & count of rows later inserted into Bigtable match. For this I am planning to develop a custom Windowing strategy so that lines from a single file get assigned to a single window based on the file name as the key that will be passed to the

问题 I have a Beam pipeline that starts off with reading multiple text files where each line in a file represents a row that gets inserted into Bigtable later in the pipeline. The scenario requires confirming that the count of rows extracted from each file & count of rows later inserted into Bigtable match. For this I am planning to develop a custom Windowing strategy so that lines from a single file get assigned to a single window based on the file name as the key that will be passed to the

问题 My Dataflow pipeline is running extremely slow. Its processing approximately 4 elements/2 with 30 worker threads. A single local machine running the same operations (but not in the dataflow framework) is able to process 7 elements/s. The script is written in Python. Data is read from BigQuery. The workers are n1-standard, and all look to be at 100% CPU utilization. The operations contained within the combine are: tokenizes the record and applies stop word filtering (nltk) stem the word (nltk)

问题 I am interested to work with persistent distributed dataflows with features similar to the ones of the Pegasus project: https://pegasus.isi.edu/ for example. Do you think there is a way to do that with dask? I tried to implement something which works with a SLURM cluster and dask. I will below describe my solution in great lines in order to better specify my use case. The idea is to execute medium size tasks (that run between few minutes to hours) which are specified with a graph which can

问题 I'm using python beam on google dataflow, my pipeline looks like this: Read image urls from file >> Download images >> Process images The problem is that I can't let Download images step scale as much as it needs because my application can get blocked from the image server. Is it a way that I can throttle the step ? Either on input or output per minute. Thank you. 回答1: One possibility, maybe naïve, is to introduce a sleep in the step. For this you need to know the maximum number of instances

问题 I am trying to run the MinimalWordCount example using the DataFlowRunner from Eclipse on windows using MinimalWordCount -->Run As Java Application from with in eclipse , its the same stock code from the example using my gcs bucket , however I consistently get the following exception , can some one let me know whats the issue here? I have verified that the bucket name is correct. I already ran the gcloud init on my Windows machine. Exception in thread "main" java.lang.RuntimeException: Failed

问题 I have a requirement to make a scalable process. The process has mainly I/O operations with some minor CPU operations (mainly deserializing strings). The process query the database for a list of urls, then fetches data from these urls, deserilize the downloaded data to objects, then persist some of the data into crm dynamics and also to another database. Afterwards I need to update the first database which urls were processed. Part of the requirement is to make the parallelism degree