The number of parallel threads which are used to upload the binaries to the remote file store (such as the s3).
The number of workers is by default 5. One of them is solely for maintenance (not for uploading files but for other tasks of the eventual binary provider).
So you cannot reduce the number of working threads to be less than 2.
On the other hand, the max value depends on the bandwidth you have (as it is parallel upload of files to remote filestore).
100 is extremely high. Usually we recommend the number of 20 which is enough for high load servers.
When you write (same goes for delete) a file on the eventual, you want to prevent a situation where another thread will write to the same path in the same time, so we are keeping a lock on the given path during this period (so in a given time, only one concurrent writer is allowed but many readers).
This parameter is to define the time for a thread to try to acquire a lock on a given path (by default 5000).
The eventual binary provider scans the _add folder and the _delete folder to check for artifact to upload/delete to/from the remote filestore.
This is being done on iterations and the intervals are determined by this parameter (by default it is set to 5000 ms).