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 transaction commit processing to allow a synchronizing secondary database to catch up to the primary end of log in order to transition to the synchronized state. This is an expected wait when a secondary database is catching up. Information from Microsoft®

Very rare

This wait never occurs for most instances

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

Prevalence of HADR_SYNCHRONIZING_THROTTLE across the Spotlight Population

For 24 % of hours with this wait, average wait time is around 3 ms

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

22 instances contributed data to this chart

Latency Distribution of HADR_SYNCHRONIZING_THROTTLE across the Spotlight Population