You want to enable Continuous uploading of the Access log to a remote logging server, but you want to know if that will impact the performance of the ProxySG.
There is no additional impact to the ProxySG CPU utilization or ProxySG memory utilization when using Continuous upload mode for Access logging versus Periodic upload.
Access Logs may be uploaded compressed (gzip) or non-compressed (text). When using Continuous, non-compressed upload a slightly lower CPU usage may happen because the log entries are not getting compressed. However, non-compressed log entries being transferred over the network to the remote server will have a longer network transfer time because more bytes will need to be transferred. When using Continuous upload (compressed or non-compressed) Access Log entries do not need to be stored on the local disk (unless there is a network issue) so fewer disk writes and reads will occur. When choosing between compressed (gzip) and non-compressed (text) uploads the time to compress log entries will typically be less than the additional network transfer time for uncompressed uploads.