Merge Replication over VPN over the Pond

Hi,
We have two servers, one in North America, one in Europe, that are connected
by a firewall VPN. The firewalls have built-in encryption processors, so the
VPN encryption doesn't cause a speed issue. We are running SQL 2000 SP3 on
Windows 2003 Server.
We are currently hosting about 25 databases on the European server and using
Merge Replication to replicate between the servers. The Merge Agents are set
up to start every hour, and they are also running continuously (I manually
added the -continuous flag to the merge agent run step).
Right now we get various error messages during peak usage times. I have
already gone into the agent profiles and tweaked them based on
recommendations from this site among others, but we still get these errors...
I have read somewhere (including in Hilary's book) that there is an
-FTPAddress flag that you can put in the merge agent. Does this mean that if
you put that flag into the agent details, it will use FTP instead of TCP/IP
to transmit the merge data?
We get significantly faster download speeds when using FTP, so I would like
to set up as much FTP usage as possible, not just FTP'ing of the snapshots
(only once/week), but FTP of all merging information.
Right now our publisher with live data is in Europe, and our distributor is
in North America on the same server as the "backup" subscription databases.
Any insight would be greatly appreciated.
FTP uses tcp/ip protocol under the covers, so it probably won't help you.I
suspect you see performance improvements using FTP in applying your
snapshots as they are likely compressed. Otherwise I don't think you will
see performance improvements over UNC with FTP.
Exactly what are the error messages you are getting with merge replication.
Many of these errors are transitory and clear the next time the merge agent
runs.
Merge is a difficult beast to tune - you might want to review -
http://msdn.microsoft.com/library/de...artitioned.asp
Hilary Cotter
Looking for a SQL Server replication book?
http://www.nwsu.com/0974973602.html
Looking for a FAQ on Indexing Services/SQL FTS
http://www.indexserverfaq.com
"Hugh" <Hugh@.discussions.microsoft.com> wrote in message
news:E34D79B5-A506-4129-8F87-B94D90558F4D@.microsoft.com...
> Hi,
> We have two servers, one in North America, one in Europe, that are
> connected
> by a firewall VPN. The firewalls have built-in encryption processors, so
> the
> VPN encryption doesn't cause a speed issue. We are running SQL 2000 SP3
> on
> Windows 2003 Server.
> We are currently hosting about 25 databases on the European server and
> using
> Merge Replication to replicate between the servers. The Merge Agents are
> set
> up to start every hour, and they are also running continuously (I manually
> added the -continuous flag to the merge agent run step).
> Right now we get various error messages during peak usage times. I have
> already gone into the agent profiles and tweaked them based on
> recommendations from this site among others, but we still get these
> errors...
> I have read somewhere (including in Hilary's book) that there is an
> -FTPAddress flag that you can put in the merge agent. Does this mean that
> if
> you put that flag into the agent details, it will use FTP instead of
> TCP/IP
> to transmit the merge data?
> We get significantly faster download speeds when using FTP, so I would
> like
> to set up as much FTP usage as possible, not just FTP'ing of the snapshots
> (only once/week), but FTP of all merging information.
> Right now our publisher with live data is in Europe, and our distributor
> is
> in North America on the same server as the "backup" subscription
> databases.
> Any insight would be greatly appreciated.
|||Hi Hilary,
Thanks for the response. Here are some of the errors we get:
The subscription to publication "xxxxx" is invalid. General Network Error.
or...
The agent is suspect. No response within the last 10 minutes.
or...
The process could not enumerate deletions at the Publisher. General Network
Error.
You are right, these errors go away when the merge agent restarts itself,
but I would like to get rid of them entirely, of course.
I have read the article you suggested, but we aren't doing any partitioning,
as the entire database is being mirrored. But from what I read there, the
replication will work better if the database is tuned, so looking into index
tuning is probably a good next step?
Oh, and when is the Merge book coming out? ;)
Thanks for the help.
|||Hi Hugh,
Just curious, what Firewall VPN product do you use? I'm intrigued by the
built-in encryption processor feature...
Thanks,
Brad
"Hugh" <Hugh@.discussions.microsoft.com> wrote in message
news:E34D79B5-A506-4129-8F87-B94D90558F4D@.microsoft.com...
> Hi,
> We have two servers, one in North America, one in Europe, that are
> connected
> by a firewall VPN. The firewalls have built-in encryption processors, so
> the
> VPN encryption doesn't cause a speed issue. We are running SQL 2000 SP3
> on
> Windows 2003 Server.
> We are currently hosting about 25 databases on the European server and
> using
> Merge Replication to replicate between the servers. The Merge Agents are
> set
> up to start every hour, and they are also running continuously (I manually
> added the -continuous flag to the merge agent run step).
> Right now we get various error messages during peak usage times. I have
> already gone into the agent profiles and tweaked them based on
> recommendations from this site among others, but we still get these
> errors...
> I have read somewhere (including in Hilary's book) that there is an
> -FTPAddress flag that you can put in the merge agent. Does this mean that
> if
> you put that flag into the agent details, it will use FTP instead of
> TCP/IP
> to transmit the merge data?
> We get significantly faster download speeds when using FTP, so I would
> like
> to set up as much FTP usage as possible, not just FTP'ing of the snapshots
> (only once/week), but FTP of all merging information.
> Right now our publisher with live data is in Europe, and our distributor
> is
> in North America on the same server as the "backup" subscription
> databases.
> Any insight would be greatly appreciated.
|||Hi Brad,
Sonicwalls have a built in HMAC MD5 processor for VPN, so if you leave the
vpn tunnels with thier default encryption settings, everything runs through
the encryption processor.
Cheers,
Hugh.