What happens when a streaming expression is sent to an alias

When you send an expression to an alias named "myAlias" pointing to N number of collections, each having M number of replicas, how does it work? Is the same expression executed in all of the NxM machines at the same time? Or a random node is selected from the NxM replica's nodes? Or something e

log4j 2.17.1 addressing CVE-2021-44832

Dear users, according to log4j's security announcements there is another CVE (CVE-2021-44832) which is supposed to be fixed with version 2.17.1. Is this CVE critical for Solr as well? Best regards, Chris