It depends upon the kind of SAS Studio you have. There are 3 different editions, namely
1. SAS Studio Mid-Tier : a full SAS Client which connects to the SAS infrastructure like SAS EG or SMC ; in this case, the connection trace will be found In the same Metadata log file
2. SAS Studio Basic edition : a shortened version - fully functional though except for Metadata access- coming without a SAS Metadata Server or Information Technology components (it connects directly, server-side, to the SAS process using only an Object Spawner, security/authentication is left to the Linux server ; this offer being available only on Linux) : I suppose in this case, the only connection record might be found in the Obj. Spawner log file ? in addition to the /var/log/secure general logfile of course.
3. SAS Studio Single-User, coming with SAS Foundation PC is the standalone version which runs on a PC "locally" without any independent "daemon"/"service"/"server", thus without any centralised log file obviously.
See https://support.sas.com/documentation/cdl/en/webeditorag/69506/HTML/default/viewer.htm#titlepage.htm
Incidentally, SAS University Edition look like an embedded version of SAS Studio Basic edition. If anyone could confirm ?