The sleep only occurs on connection errors and server timeouts which suggest a node is down and the cluster is reforming. The sleep does not occur when the client's socketTimeout expires.
Reads do not have to sleep when a node goes down because the cluster does not shut out reads during cluster reformation. The default for reads is zero.
The default for writes is also zero because writes are not retried by default. Writes need to wait for the cluster to reform when a node goes down. Immediate write retries on node failure have been shown to consistently result in errors. If maxRetries is greater than zero on a write, then sleepBetweenRetries should be set high enough to allow the cluster to reform (>= 3000ms).
Default: 0 (do not sleep between retries)
Assembly: AerospikeClient (in AerospikeClient.dll) Version: 220.127.116.11 (5.1.1)
public int sleepBetweenRetries