Showing posts with label instances. Show all posts
Showing posts with label instances. Show all posts

Monday, March 26, 2012

Replication Reliability in SQL Server 2000

Any idea as to how SQL Server ensures that no data is lost during replication. In my project we have some across several instances where the SQL server indicates that the data has been replicated but it is not recieved at the other end. The network is not very reliable, in case the network link is lost during replication how does SQL ensure no data is lost. If you know the answers or have any documents please share the same.

Thanks,

Shalin Parmar

It depends on the replication type you deploy.

You need a consistent connection when you use Transactional Replication. However, you do not need a consistent connection with Merge replication. Only modifications are replicated with these two types of replication.

Your data loss may be because of some conflicts if you have more than one Subscriber in your replication frame. If so, there are conflict solutions to use with replication.

Ekrem ?nsoy
MCP, MCDST, MCDBA, MCAD.Net, MCSD.Net, MCSA, MCSE

Tuesday, March 20, 2012

Replication performance question

Hello to all,

I have a performance question: we have a cluster with 2 SQL instances on 1 node (another instance is on another node, but no link with my current problem!). Let's call them C1SQL1 and C1SQL2.

This node is a Hyperthreaded Xeon 2.8Ghz with 1 gig of memory.

These 2 instances are using transactionnal replication and are configured as the distributor and publisher. C1SQL1 is not using much power, it's a small replication with around 10 agents. C1SQL2 is a bit heavier, with around 100 distribution agents. C1SQL2 has around 50 subscribers in 12 publications, but not all subscribers are used in each publications.

Once in a while, this cluster node impacts our production environment (since it's also a production server) and we're wondering if performance wise, it's really not powerfull enough to be the distributor?

I've isolated C1SQL2 on it's own logical CPU, and in idle mode, the replication workload (history, checking if new transactions are made) peaks at around 15-50% each 4-10 seconds.

Can I have any input on this?

Thanks!

Can you give some more detail, I'm not clear on what the problem/symptoms are. Regardless, have you been monitoring disk, memory and CPU to rule out hardware bottleneck? The replication workload you mention in the last sentence, are you talking about logreader agent or distribution agent? Is this SQL 2000 or 2005? Are you running Repl MOnitor in the background?

Monday, March 12, 2012

Replication over different computers

Dear All,
I can successfully create merge replication on the same
computer with two database instances. However, it didn't
success if I replicate over two computers.
I use push subscription and the subscriber seems
nothing to set (set the replication on the publisher).
Therefore, how can I control the access rights or else to
replicate to another computer?
Patrick
Patrick,
the sql server agnt's login must be in the db_owner role on the subscriber
database, db_owner in the distribution database and db_owner of the
publishing database and have the correct rights to the snapshot share.
What is the error when you run the merge agent?
Regards,
Paul Ibison
|||Is there any step-by-step guide to setup replication over
different computers

>--Original Message--
>Patrick,
>the sql server agnt's login must be in the db_owner role
on the subscriber
>database, db_owner in the distribution database and
db_owner of the
>publishing database and have the correct rights to the
snapshot share.
>What is the error when you run the merge agent?
>Regards,
>Paul Ibison
>
>.
>
|||Patrick,
BOL has all the details but not as a setup guide.
These links have step-by-step graphical setups:
http://www.mssqlcity.com/Articles/Re...MR/SetupMR.htm
http://www.sqlservercentral.com/arti...?categoryid=26
HTH,
Paul Ibison

Replication or bcp or DTS?

Hi,
I have 2 instances of databases in 2 different cities.Data entry /
updations are going on at both the sides.At any point of time data in
both the databases should be same.Currently every alternate day, i am
performing update / insert / deletes on incremental basis on both the
sides.
Can I implement replcation? What r the requisites I have to follow for
replication?

I do not have permenant connectyvity but I need to connect using ISDN
line to a remote location as and when required for doing
synchrinisation of data.

Thanks in advance.

Regards
Rohit

--
Posted using the http://www.dbforumz.com interface, at author's request
Articles individually checked for conformance to usenet standards
Topic URL: http://www.dbforumz.com/General-Dis...pict236236.html
Visit Topic URL to contact author (reg. req'd). Report abuse: http://www.dbforumz.com/eform.php?p=819975Rohit (UseLinkToEmail@.dbForumz.com) writes:
> I have 2 instances of databases in 2 different cities.Data entry /
> updations are going on at both the sides.At any point of time data in
> both the databases should be same.Currently every alternate day, i am
> performing update / insert / deletes on incremental basis on both the
> sides.
> Can I implement replcation? What r the requisites I have to follow for
> replication?
> I do not have permenant connectyvity but I need to connect using ISDN
> line to a remote location as and when required for doing
> synchrinisation of data.

I'm a little confused, since you say that at any point in time, the
contents of the databases should be the same. But then you talk about
not having permanent connectivity. Is that the connectivity between
the databases, or your own connectivity.

The gist of replication is that the I in ACID for transactions is
relaxed. That is, transactions should normally be Atomic, Consistent,
Immediate and D-something. With replication, you say that I does not
matter. A transaction can be replicated later at any time. This is good
if you have disconnected servers. For connected servers, replication
can still be acceptable, since the delay in most cases will not be
noticeable.

Since you need to send data in both directions, it looks as if you are
into merge replication. There are probably a bunch of requirements,
for instance the table must have GUID as keys. And then you need rules
to handle conflicts. (What if the same row is updated at both sites?)

My own knowledge only goes as far about this, so I would recommend you
to ask in microsoft.sqlserver.public.replication.
--
Erland Sommarskog, SQL Server MVP, esquel@.sommarskog.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techin.../2000/books.asp|||"" wrote:
> Rohit (UseLinkToEmail@.dbForumz.com) writes:
> > I have 2 instances of databases in 2 different
> cities.Data entry /
> > updations are going on at both the sides.At any point of
> time data in
> > both the databases should be same.Currently every alternate
> day, i am
> > performing update / insert / deletes on incremental basis on
> both the
> > sides.
> > Can I implement replcation? What r the requisites I have to
> follow for
> > replication?
> > I do not have permenant connectyvity but I need to connect
> using ISDN
> > line to a remote location as and when required for doing
> > synchrinisation of data.
> I'm a little confused, since you say that at any point in
> time, the
> contents of the databases should be the same. But then you
> talk about
> not having permanent connectivity. Is that the connectivity
> between
> the databases, or your own connectivity.
> The gist of replication is that the I in ACID for transactions
> is
> relaxed. That is, transactions should normally be Atomic,
> Consistent,
> Immediate and D-something. With replication, you say that I
> does not
> matter. A transaction can be replicated later at any time.
> This is good
> if you have disconnected servers. For connected servers,
> replication
> can still be acceptable, since the delay in most cases will
> not be
> noticeable.
> Since you need to send data in both directions, it looks as if
> you are
> into merge replication. There are probably a bunch of
> requirements,
> for instance the table must have GUID as keys. And then you
> need rules
> to handle conflicts. (What if the same row is updated at both
> sites?)
> My own knowledge only goes as far about this, so I would
> recommend you
> to ask in microsoft.sqlserver.public.replication.
> --
> Erland Sommarskog, SQL Server MVP, esquel@.sommarskog.se
> Books Online for SQL Server SP3 at
> http://www.microsoft.com/sql/techin.../2000/books.asp

Thanks for your reply. probably I wrote it in a wrong way.
There is no permenant connectivity between the two locations. Whenever
mself / management decides to Synch. the data I connect using ISDN
connection , perform export / Import Using BCP at both the sides and
then run SQL Script to push the incremental data inside the database.
Before going to the database it comes to a buffer database FROM text
files.

regards
Rohit

--
Posted using the http://www.dbforumz.com interface, at author's request
Articles individually checked for conformance to usenet standards
Topic URL: http://www.dbforumz.com/General-Dis...pict236236.html
Visit Topic URL to contact author (reg. req'd). Report abuse: http://www.dbforumz.com/eform.php?p=821317|||Rohit (UseLinkToEmail@.dbForumz.com) writes:
> Thanks for your reply. probably I wrote it in a wrong way.
> There is no permenant connectivity between the two locations. Whenever
> mself / management decides to Synch. the data I connect using ISDN
> connection , perform export / Import Using BCP at both the sides and
> then run SQL Script to push the incremental data inside the database.
> Before going to the database it comes to a buffer database FROM text
> files.

OK. As I said, merge replication could be worth looking into. But I know
too little of merge replication as well as your application to say for
sure that it is a good idea.

--
Erland Sommarskog, SQL Server MVP, esquel@.sommarskog.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techin.../2000/books.asp