To avoid DAG switchover issues, you should always collapse the MAPI networks in a DAG.

The following Technet article state that we “should” or we “must” do it:

http://technet.microsoft.com/en-us/library/dd298065.aspx#Dat

http://technet.microsoft.com/en-us/library/dd638104.aspx#NR

… and Tim McMichael explains why :

http://blogs.technet.com/b/timmcmic/archive/2011/09/26/exchange-2010-collapsing-dag-networks.aspx

Bookmark to Rhoderick’s blog :

http://blogs.technet.com/b/rmilne/archive/2012/07/05/how-to-fix-log-parser-log-row-too-long.aspx

Note : The maximum value is *not* 0xFFFFFFFF.  It’s actually 0x00785111 (hard coded in the LogParser code)

To determine the value to put on the below registry key, take the performance log file that you have in CSV format (works only on CSV formats), copy the headers only, and paste it in Notepad, then save it as a txt file. The size of the txt file determines the minimum value we need to put on the CSVInMaxRowSize attribute (in Bytes) :

x86

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Log Parser

REG_DWORD CSVInMaxRowSize 393216 decimal

To automate adding on x86 machines:

REG.exe ADD "HKLM\Software\Microsoft\Log Parser" /v CSVInMaxRowSize /t REG_DWORD /d 393216

x64

HKLM\Software\Wow6432Node\Microsoft\Log Parser

REG_DWORD CSVInMaxRowSize 393216 decimal

To automate adding on x64 machines:

REG.exe ADD "HKLM\Software\Wow6432Node\Microsoft\Log Parser" /v CSVInMaxRowSize /t REG_DWORD /d 393216