OK, This is a common issue in Spark Structured Streaming (SSS), where the source generates data faster than Spark can process it. SSS doesn't have a built-in mechanism for directly rate-limiting the incoming data stream itself. However, consider the following:
- Limit the rate at which data is produced. This can involve configuring the data source itself to emit data at a controlled rate or implementing rate limiting mechanisms in the application or system that produces the data. - SSS supports backpressure, which allows it to dynamically adjust the ingestion rate based on the processing capacity of the system. This can help prevent overwhelming the system with data. To enable backpressure, set the appropriate configuration properties such as spark.conf.set("spark.streaming.backpressure.enabled", "true") and spark.streaming.backpressure.initialRate. - Consider adjusting the micro-batch interval to control the rate at which data is processed. Increasing the micro-batch interval and reduce the frequency of processing, allowing more time for each batch to be processed and reducing the likelihood of out-of-memory errors.. spark.conf.set("spark.sql.streaming.trigger.interval", "<n> seconds" - Dynamic Resource Allocation (DRA), Not implemented yet. DRA will automatically adjust allocated resources based on workload. This ensures Spark has enough resources to process incoming data within the trigger interval, preventing backlogs and potential OOM issues. >From Spark UI, look at the streaming tab. There are various statistics there. In general your Processing Time has to be less than your batch interval. The scheduling Delay and Total Delay are additional indicator of health. HTH Mich Talebzadeh, Technologist | Solutions Architect | Data Engineer | Generative AI London United Kingdom view my Linkedin profile <https://www.linkedin.com/in/mich-talebzadeh-ph-d-5205b2/> https://en.everybodywiki.com/Mich_Talebzadeh *Disclaimer:* The information provided is correct to the best of my knowledge but of course cannot be guaranteed . It is essential to note that, as with any advice, quote "one test result is worth one-thousand expert opinions (Werner <https://en.wikipedia.org/wiki/Wernher_von_Braun>Von Braun <https://en.wikipedia.org/wiki/Wernher_von_Braun>)". On Sun, 7 Apr 2024 at 15:11, Baran, Mert <mert.ba...@fau.de> wrote: > Hi Spark community, > > I have a Spark Structured Streaming application that reads data from a > socket source (implemented very similarly to the > TextSocketMicroBatchStream). The issue is that the source can generate > data faster than Spark can process it, eventually leading to an > OutOfMemoryError when Spark runs out of memory trying to queue up all > the pending data. > > I'm looking for advice on the most idiomatic/recommended way in Spark to > rate-limit data ingestion to avoid overwhelming the system. > > Approaches I've considered: > > 1. Using a BlockingQueue with a fixed size to throttle the data. > However, this requires careful tuning of the queue size. If too small, > it limits throughput; if too large, you risk batches taking too long. > > 2. Fetching a limited number of records in the PartitionReader's next(), > adding the records into a queue and checking if the queue is empty. > However, I'm not sure if there is a built-in way to dynamically scale > the number of records fetched (i.e., dynamically calculating the offset) > based on the system load and capabilities. > > So in summary, what is the recommended way to dynamically rate-limit a > streaming source to match Spark's processing capacity and avoid > out-of-memory issues? Are there any best practices or configuration > options I should look at? > Any guidance would be much appreciated! Let me know if you need any > other details. > > Thanks, > Mert > > > --------------------------------------------------------------------- > To unsubscribe e-mail: user-unsubscr...@spark.apache.org > >