The setting for Maximum parallel connections for inSync storage as shown in the below UI defines the upper limit for parallel backup or restore operations that can be performed on a particular storage.
This article discusses how the number of parallel connections set on the storage affect the data synchronization and storage performance.
Effect on data synchronization
If the parallel connections to a storage exceed the set value, then a new connection request from a client will be rejected by the inSync server. For this event it will log an error message stating "Server Busy, try again later" under the inSyncServer.log & the inSync Client GUI.
It will keep on trying every 10 minutes for a free connection back to the server to initiate a backup.
Effect on storage performance
inSync storage throughput or the IOPS is shared by concurrent connections. High number of connections set on the Storage will put extra stress on the storage and would impact the overall performance, resulting in slow backups or restore.
Keeping an optimum value of maximum parallel connection helps clients to complete sync faster and permits other clients to sync.
Therefore, it is recommended to keep this value to 10% of total users assigned to a particular storage.