Fetch new data from kinesis for every minute.

[pranathisg97]

I want to fetch new data from kinesis source for every minute.

I'm using "minFetchPeriod" option and specified 60s. But this doesn't seem to be working.

Streaming query:

spark \

 .readStream \

 .format("kinesis") \

 .option("streamName", kinesis_stream_name) \

 .option("region", region name) \

 .option("initial Position", "latest") \

 .option("awsAccessKey", awsAccessKey) \

 .option("awsSecretKey", aws_secret_access_key)\

.option("minFetchPeriod","60s")

Can anyone help me on this ? I'm new to this topic.

[Debayan]

Hi, What is the DBR you are running on it? Also, what is the error you get when it is not working?

[pranathisg97]

Hi, DBR is 12.1

Error : "java.lang.IllegalArgumentException: maxFetchDuration needs to be a duration string such as '10s' for 10 seconds or '2m' for 2 minutes. Also needs to be greater than minFetchPeriod in order to avoid falling behind in the stream".

Do I have to configure maxFetchDuration whenever I configure minFetchPeriod ?

[Anonymous]

Hi @Pranathi Girish​ 

Hope all is well! Just wanted to check in if you were able to resolve your issue and would you be happy to share the solution or mark an answer as best? Else please let us know if you need more help. 

We'd love to hear from you.

Thanks!

[pranathisg97 · Accepted solution]

Hi,

I was able to solve the issue by specifying maxFetchDuration value more than minFetchPeriod. However I didn't get the purpose of specifying maxFetchDuration value greater than or equal to minFetchPeriod value.

spark \

 .readStream \

 .format("kinesis") \

 .option("streamName", kinesis_stream_name) \

 .option("region", region name) \

 .option("initial Position", "latest") \

 .option("awsAccessKey", awsAccessKey) \

 .option("awsSecretKey", aws_secret_access_key)\

.option("maxFetchDuration","60s")\

.option("minFetchPeriod","60s")

[jose_gonzalez]

I would like to share the following docs with best practices when using kinesis https://docs.databricks.com/structured-streaming/kinesis-best-practices.html please check this doc. it will help you to undertand what does maxFetchDuration does.

[pranathisg97]

Hi @Jose Gonzalez​ ,

Thanks for sharing the document. I would like to share my understanding from the document. Please correct me if I'm wrong.

minFetchPeriod is the time interval between consecutive pre-fetch between kinesis and spark. maxFetchDuration is the how long the pre-fetched data will be stored in buffer. In my case, after 60s data will be available to process.

But how the data from kinesis is pre-fetched?

[Anonymous]

Hi @Pranathi Girish​ 

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