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 for the synchronized secondary databases to harden the log. This wait is also reflected by the Transaction Delay performance counter. This wait type is expected for synchronized availability groups and indicates the time to send, write, and acknowledge log to the secondary databases. Information from Microsoft®

Very rare

This wait never occurs for most instances

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

Prevalence of HADR_SYNC_COMMIT across the Spotlight Population

For 16 % of hours with this wait, average wait time is around 1.8 ms

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

333 instances contributed data to this chart

Latency Distribution of HADR_SYNC_COMMIT across the Spotlight Population