Hello Irakli and thank you for your question. I guess that somehow Flink enters the "reactive" mode while the adaptive scheduler is not configured.
I would go with 2 options to isolate your issue: • Try with forcing the scheduling mode (https://nightlies.apache.org/flink/flink-docs-release-1.18/docs/deployment/elastic_scaling/#adaptive-scheduler) in your configuration: `jobmanager.scheduler: adaptive` • Let Flink decide for the runtime mode: if the source is bounded, you don't need `env.setRuntimeMode(RuntimeExecutionMode.BATCH)`, as Flink will understand that correctly. Can you try one of the two and see if that helps? For the rest: "running it in the "BATCH" mode was better as I don't have to deal with the Watermark Strategy". Still, you could opt for a simple watermarking strategy and stay with the streaming mode (for example, 'BoundedOutOfOrcerness': https://nightlies.apache.org/flink/flink-docs-master/docs/dev/datastream/event-time/generating_watermarks/#watermark-strategies-and-the-kafka-connector). On Mar 4, 2024 at 15:54 +0100, irakli.keshel...@sony.com <irakli.keshel...@sony.com>, wrote: > Hello, > > I have a Flink job which is processing bounded number of events. Initially, I > was running the job in the "STREAMING" mode, but I realized that running it > in the "BATCH" mode was better as I don't have to deal with the Watermark > Strategy. The job is reading the data from the Kafka topic and was running > fine in the "STREAMING" mode. > I switched the job to the "BATCH" mode by setting > "env.setRuntimeMode(RuntimeExecutionMode.BATCH)". I changed the Kafka Source > to be bounded by setting ".setBounded(OffsetsInitializer.latest())" to the > source builder and I updated the Watermark strategy to be > "WatermarkStrategy.noWatermarks()". > After making these changes and deploying the job I end up with following > error: "java.lang.IllegalStateException","error.message":"Adaptive Scheduler > is required for reactive mode". I couldn't find any documentation online > which is connecting "Adaptive Scheduler" to the "BATCH" processing. Does > anyone know where this error is coming from and how I can deal with it? > > Cheers, > Irakli