We have configured Log Shipping for our databases that reside on a SQL2012 cluster. Everything is working fine from a synchronicity perspective, but we are seeing a 16 second delay from the LS Backup job starting to the Log Shipping Agent doing its business.
We wrote some simple SQL to help demonstrate this,
DECLARE @CMDvarchar(4000)
SET @CMD='"C:\Program Files\Microsoft SQL Server\110\Tools\Binn\sqllogship.exe" -Backup <OUR_PRIMARY_ID> -server <OUR_SERVER>'
SELECTGETDATE()
EXECxp_cmdshell@CMD
SELECTGETDATE()
You can see a 16 second delay from the initial timestamp to the START OF TRANSACTION LOG BACKUP timestamp:
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2016-03-22 09:24:06.793
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NULL
Microsoft (R) SQL Server Log Shipping Agent
[Assembly Version = 11.0.0.0, File Version = 11.0.6020.0 ((SQL11_PCU_Main).151020-1526 )]
Copyright (c) 2012 Microsoft. All rights reserved.
NULL
2016-03-22 09:24:22.07 ----- START OF TRANSACTION LOG BACKUP -----
2016-03-22 09:24:22.21 Starting transaction log backup. Primary ID: '35bbb26c-fc9b-452d-b930-360153334d6d'
2016-03-22 09:24:22.22 Retrieving backup settings. Primary ID: '35bbb26c-fc9b-452d-b930-360153334d6d'
2016-03-22 09:24:22.22 Retrieved backup settings. Primary Database: 'testLS', Backup Directory: '\\servername\Backups\servername\instance_CM\testLS\LOG', Backup Retention Period: 4320 minute(s), Backup Compression: Server Default
2016-03-22 09:24:22.29 Backing up transaction log. Primary Database: 'testLS', Log Backup File: '\\servername \Backups\servername\instance_CM\testLS\LOG\testLS_20160322092422.trn'
2016-03-22 09:24:22.43 Deleting old log backup files. Primary Database: 'testLS'
2016-03-22 09:24:22.50 The backup operation was successful. Primary Database: 'testLS', Log Backup File: '\\servername \Backups\servername \instance _CM\testLS\LOG\testLS_20160322092422.trn'
2016-03-22 09:24:22.51 ----- END OF TRANSACTION LOG BACKUP -----
NULL
Exit Status: 0 (Success)
NULL
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2016-03-22 09:24:22.640