Microsoft SQL Server 2008 R2 Unleashed- P65 potx

When the distributor is configured and the distribution database is created, a series of replication agents managed by SQL Server Agent are created, with various duties, as described ear

584 CHAPTER 19 Replication

FIGURE 19.30 Configuring the distributor and enabling a publisher in progress

option (lower-right side of this dialog) Make sure you see Success after each step of this

configuration

Now is probably a good time to locate that distributor setup and enabling publication

script and drop it into your replication administrator folder that you keep in a safe place

Figure 19.31 shows what this script looks like Notice that the password is not displayed

The details of these scripts are described later in this chapter, in the “Scripting

Replication” section

When the distributor is configured and the distribution database is created, a series of

replication agents (managed by SQL Server Agent) are created, with various duties, as

described earlier in this chapter Figure 19.32 shows the initial set of agents created on the

distribution server (as seen from the Job Activity Monitor under the SQL Server Agent) No

agents exist yet that actually publish data or distribute data Those agents are created later,

as you start publishing and subscribing

Creating a Publication

When the distribution database has been created and publishing has been enabled on the

server, you can create and configure a publication In SQL Server Management Studio, you

start by locating the Replication node under the publication server from which you want

to publish data (the DBARCH-LT2\SQL08DE01 named instance in this example) Figure 19.33

shows the program item option when you right-click the Replication node under what

will be the publication server As you can see, there are three options; one to create a new

publication, one to create a new Oracle publication, and one to create a new subscription

FIGURE 19.31 The script generated for creating the distributor and enabling a publisher

FIGURE 19.32 Initial replication agents on the distributor

586 CHAPTER 19 Replication

FIGURE 19.33 The New Publication item option on the server that will be the publisher

You should choose to create a new publication (the first option) When you do, the New

Publication Wizard is launched

Here’s how you create a new publication:

1 The first New Publication Wizard page outlines the two things that can be done with

this wizard The options are “Select the data and database objects you want to

repli-cate” and “Filter the published data so that subscribers receive only the data they

need.” After this splash page, you need to specify how you want to distribute the

data for this new publication As you can see in Figure 19.34, you should use a

remote distributor (the DBARCH-LT2\SQL08DE02 named instance) to distribute data for

this new publication you are defining

2 When you are asked to provide a password that will be used to establish the

admin-istrative link to the distributor, supply it It should be the same one you specified

earlier when setting up the distribution server

3 Identify the database on which you are going to set up a publication (see Figure

19.35) For this example, choose to create a publication on the

AdventureWorks2008 database

4 Choose the type of replication method for this publication: Snapshot Publication,

Transactional Publication, Transactional Publication with Updateable Subscriptions,

or Merge Publication Method of Replication For this example, select Transactional

Publication

FIGURE 19.34 Specifying the remote distribution server for the new publication

FIGURE 19.35 Choosing the database that contains the data or objects you want to publish

5 Next, you are presented with the place where you specify what tables and other

objects to publish These will become your articles You can specify filtering of any

selected articles, where appropriate To keep this simple, just choose the primary

stored procedures, views, indexed views, user-defined functions, and tables of the

AdventureWorks2008 database for this publication (You do not select any filtering at

this time.) Figure 19.36 shows the Articles specification page Also in Figure 19.36,

you can view the article properties that dictate how all article objects should be

handled by replication (via the Article Properties button in the upper-right corner of

this wizard screen) An example of this is specifying the delete delivery format

behavior for this publication (for all tables) to be Do Not Replication Delete

Statements or Use Stored Procedures to Do the Deletes and not individual delete

statements

588 CHAPTER 19 Replication

FIGURE 19.36 Choosing the tables and other objects that determine the articles to publish

The next wizard screen carefully analyzes what you are asking to become articles and

highlights any dependencies that must be considered as part of replication A good

example of an article issueis that indexed views require the tables to which they are

bound to be part of the replication

6 When the Snapshot Agent wizard configuration screen prompts you to either create a

snapshot immediately or at some scheduled time and to keep the snapshot available

to initialize subscriptions, select to create a snapshot immediately and keep it

avail-able to initialize the subscription As part of this snapshot agent creation, you have to

specify under what security credentials you want the agent security to run In

addi-tion, you can specify if you want the log reader agent to use the same security settings

as the snapshot agent The rule of thumb here is to keep it simple and let these agents

use the same security settings (as shown in Figure 19.37)

7 The wizard now has enough information to create the publication When the wizard

actions are summarized for you, choose to create the publication and generate a

script file with all the steps to create the publication in it Again, this script

genera-tion part is highly recommended You certainly don’t want to have to go through

this wizard over and over Once is enough

8 When the summary of all choices made in the creation of a new publication is listed

in the Complete the Wizard screen, name the publication appropriately Your

publi-cation names should contain the type of publipubli-cation method being used (for

exam-ple, Snapshot, Transactional, Merge) and any other identifying qualifier that seems

appropriate (usually reflecting the scope of the publication) Figure 19.38 shows this

summary of actions and the publication name PUBLISH AdventureWorks2008

-Transactional

FIGURE 19.37 Agent security for snapshot agent and log reader agent

FIGURE 19.38 Publication action summary and naming the publication before it is created

590 CHAPTER 19 Replication

FIGURE 19.39 The publication steps and status, along with the report generated during this

process

The actual creation of the publication is next An action progress screen appears, showing

each step (action) and indicating any errors or warnings occurring in the publication

creation process To view any errors or warnings, you simply click the Report button in

the lower-right side after the processing completes As you can see in Figure 19.39, this

report lists, by name, all articles created and that the snapshot agent is starting This is

where all the initial action takes place

As part of this process, several new agents (jobs) are added; they implement this

publica-tion using the designated distributor There are no subscribers yet; they come later Figure

19.40 shows the new jobs (agents) and publication entries You are now ready to create

subscriptions against this publication

As you can see in Figure 19.41, if you launch Replication Monitor (from the Replication

node under the publication server), you can see the newly created publication and its

status, and you have access to any servers subscribing to it (none yet), along with the

common replication jobs that are servicing this publication

Because you chose to execute the snapshot immediately, the snapshot executes and

utilizes the snapshot folder to generate the schema files (.sch files), data snapshot files

FIGURE 19.40 SQL Server Management Studio and the new publication agents (snapshot

agent, distribution agent, and so on) and the new local publication

FIGURE 19.41 Replication Monitor, viewing the status of the newly created publication (from

the publisher)

592 CHAPTER 19 Replication

FIGURE 19.42 Contents of the snapshot folder produced for the publication

(.bcp), and so on to fully enable a subscription when one is created Figure 19.42 shows

the contents of the snapshot folder being used for the publication of the

AdventureWorks2008 publication Remember that this folder must be located in a place

that is big enough to contain all the data that will be extracted and used for the snapshot;

plan ahead

Horizontal and Vertical Filtering

During the publication creation process, you could have done some filtering of the data,

either horizontally or vertically (or both at the same time) The concept of filtering was

covered earlier in this chapter Figure 19.43 illustrates all you need to do to vertically filter

(in terms of limiting what gets published to a subset of columns of a table) As you can

see, you uncheck the AccountNumber column for the Customer table so that it isn’t

included in the article for that object in this publication This might be done because

account number information needs to be more tightly controlled within your company

and shouldn’t be part of what is viewed by any subscribing systems

In addition, you can specify horizontal filters by using the Filter Rows option on a

publi-cation (publipubli-cation properties) This allows you to specify horizontal filtering on any

table you publish Figure 19.44 shows a typical row filter on the Customer table that

results in publishing North East Territory customers only (that is, those with TerritoryID

values of 1 or 2)

FIGURE 19.43 Specifying a vertical filter on the Customer table (limiting the columns to be

published)

FIGURE 19.44 Specifying a horizontal filter on the Customer table (limiting the rows to be

published)