Waitopedia is a comprehensive resource of information about SQL Server waits.

The description shown below is the top answer as voted by the Spotlight community.

The charts are based on 2.1 TB of data collected from 4207 instances uploaded by 323 Spotlight users over an 8 week period.


Category: Other
SQL Server versions: 2012, 2014, 2016, 2017


1 Answer


Waiting for messages to be sent to the partner when the maximum number of queued messages has been reached. Indicates that the log scans are running faster than the network sends. This is an issue only if network sends are slower than expected. Information from Microsoft®

Very rare

This wait never occurs for most instances

For each of 4207 instances, we ranked HADR_DATABASE_FLOW_CONTROL on how frequent it is compared to all other recent waits. The chart shows the total of all rankings.

Prevalence of HADR_DATABASE_FLOW_CONTROL across the Spotlight Population

For 27 % of hours with this wait, average wait time is around 80 ms

For each instance, we found all the recent hours when it had a HADR_DATABASE_FLOW_CONTROL wait. We found the average latency for each of those hours.

88 instances contributed data to this chart

Latency Distribution of HADR_DATABASE_FLOW_CONTROL across the Spotlight Population