June 10, 2008 at 9:28 pm
I have setup a merge replication and many push subscriptions. The issue i am facing right now is the generation of same GUID on more than one sites when inserting a record. this thing causes conflicts at the time of synchronization and to resolve them record from one site is deleted. This thing is happening frequently please help me in this situation.
Please note that the GUID column always takes its default value which is NewSequentialID. I am badly stuck please help me as soon as possible
June 11, 2008 at 5:44 am
A GUID is only unique to that computer if it does not have a NIC. So, two machines without NIC cards can generate the same GUID relatively easily.
If it does have a NIC, they will be relatively unique, but that can intersect if machines have the same network configuration and IP addresses. That may be a good place for you to start.
It really helps uniqueness if the machines are part of the same domain because they will have unique IP addresses and machine names.
Using NewSequentialID will increase the odds to getting conflicts as the algorithm for generating sequential GUIDS is more predictable.
June 12, 2008 at 8:55 am
I believe the uniqueness is based on the MAC address of the NIC - those should be globally unique. We use merge with approx 500 subscriptions and have had no problems with newsequentialID.
To me it sounds like something else is modifying those rowguid columns, not letting the default apply?
One note, we had some existing unused columns named rowguid in one of our publications and found that it caused problems - even tho merge saw it and added column named rowguid2. Can't remember the exact behavior, but we went back and dropped the article, then dropped the exisiting rowguid column, then re-added the article - no problems after that.
jg
June 12, 2008 at 11:35 am
Let me clear the situation some more.
I have following setup
ACE_CMS\ACE_CMS (Distributer + Publisher)
LHR\LHRDB (Subscriber)
ACEGRW\CMS_GRW (Subscriber)
there are other subscribers but i haven't allowed any data to be entered on them as i have having problems with first two (as i have told in first post)
data is being directly entered on publisher database also on both subscribers
now in a table at LHR\LHRDB 2 records were entered and merged to publisher
in the same table at ACEGRW\CMS_GRW 2 records were entered but when i tried to merge the data 2 primary key conflicts were occured and i had to delete these records from one site.
checked the GUIDs they were exactly the same. i am not inserting these keys using my queries but it always takes the default value which is newsequentialid().
About IPs they are same on both sites but they are provided by my ISP and i have requested to change IP on one site. But if IP is not involved in generating GUIDs then please figure my problem out and let me know how can i resolve it
June 12, 2008 at 11:39 am
Are the MAC addresses the same?
June 12, 2008 at 11:57 am
You are getting a duplicate PK error? My guess is the rowguid is NOT the PK - merge creates a unique index to enforce the rowguid.
after a merge, the rowguids should be the same for the identical PK.
If the PK is an identity col, you need to have merge automatically manage those, or manage them yourself - we use auto.
You might know all of the above, but I am wondering if you are being led down the wrong path by focusing on the rowguids?
jg
Viewing 6 posts - 1 through 5 (of 5 total)
You must be logged in to reply to this topic. Login to reply