SAMZA-2712: AzureBlob SystemProducer: flushtimeout is not respected if main thread is uploading to azure and azure upload is stuck#1564
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rmatharu-zz merged 1 commit intoapache:masterfrom Dec 6, 2021
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…f main thread is uploading to azure and azure upload is stuck
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Symptom: calling flush on the azure blob system producer does not terminate even after the flush timeout duration expires.
Cause: main thread was uploading to azure but the connection was bad and main thread got stuck. so when the flush was called on the system producer there was no response from the main thread even after the flush timeout expired. The expected behavior is for the flush to end either in success or failure once the timeout expires.
Changes: use reactor's .subsrcibeOn with Schedulers.boundedElastic to block on the mono returned by the azure sdk. this lets us impose a timeout on the mono.block and also lets main thread monitor and jump out of the upload if upload takes longer than the flush timeout duration. After this change, irrespective of which thread (incl main) picks up the azure upload task, it will return from the upload after the flush timeout ms duration and will not hang indefinitely.
Tests: unit test added. also tested at production scale and compared to performance w/ and w/o the change and no major deviations in metrics. Note that for the sake of printing the thread name and accurate timestamp during the unit test, the log4j files were updated.
API changes: none
usage/upgrade instructions: none
Backwards compatible: yes