The autoscaler generates logs within the Trino log path on the EMR master node: /var/log/trino/trino-autoscale.log
Logs files are rotated every hour and are automatically pushed on Amazon S3 if you enabled the EMR Cluster Logging.
When S3 logging is enabled, files are retained in the EMR master node for 2 days after they are successfully shipped to S3 as defined in the EMR logpusher configuration for Trino: /etc/logpusher/trino.config