Perfmon is a not only a SQL Server but also a Windows monitoring tool that has counter objects to monitor various SQL Server counters.. There are five performance counter objects to mon
Trang 16 Select the Warnings tab (see Figure 9.16).
7 Click the Configure Alerts… button and you will see the screen
in Figure 9.17.
Figure 9.17 Configure Replication Alerts
Figure 9.16 Replication Monitor Warnings
Trang 28 Select the alert you want to configure and click the Configure button.
9 You will be taken to the Alert configuration windows.
10 In the General page you can configure the Error Message and enable the alert.
11 In the Response tab, you can configure the operation, who should receive this alert, and the means of the notification, whether it is
an email, pager, or net-sent message.
Performance Monitor
Most DBAs are using Performance Monitor (perfmon) as a monitoring tool Perfmon
is a not only a SQL Server but also a Windows monitoring tool that has counter objects to monitor various SQL Server counters The important thing about the Performance Monitor is that you have the option of using integrating with Profiler There are five performance counter objects to monitor SQL Server replication
using perfmon: Replication Agents, Replication Distribution, Replication Log Read,
Replication Merge, and Replication Snapshot
Replication Agents
There is only one counter in this counter object—Running Running can be used to
measure the number of replication agents currently running You can select the specific agent as shown in Figure 9.18
Figure 9.18 Replication Agent Counter Object
Trang 3You can see from the image in Figure 9.18 that you have the option of selecting
the following replication agents: Distribution, Logreader, Merge, Queuereader,
and Snapshot This counter is important when you want to measure whether all
the replication agents are running
Replication Distribution
This counter object provides information about the data delivery between distribution
and subscriber (Figure 9.19)
Figure 9.19 Replication Distribution Counter Object
There are three counters for the Replication Distribution Delivered Cmds measures
the number of commands per second delivered to the subscriber Delivered Trans/Sec
measures the number of transactions per second delivered to the subscriber Delivery
Latency measures current amount of time, in milliseconds, elapsed from when
transactions are delivered to the Distributor to when they are applied at the
Subscriber You can select the needed subscriber from the instance list This counter
is important to measure the performance between distributor and subscriber
Replication Logread
This counter group is to monitor transactional replication This counter has the
same counters as the Replication Distribution Counter group but it measures from
Publisher to Distributor
Replication Merge
This counter group consists of three counters, Conflicts/Sec, Downloaded Changes/Sec,
and Uploaded Changes/Sec Conflicts/Sec measures the number of conflicts per second
occurring during the merge process Conflicts will happen if you haven’t configured
Trang 4conflict resolution This counter is to measure the conflicts Downloaded Changes/Sec
measures the number of rows per second merged from the Publisher to the
Subscriber, and Uploaded Changes/Sec measures the number of rows per second
merged from the Subscriber to the Publisher The last two counters are to measure the load of the merge replication By integrating Performance Monitor with profiler, you can find the queries from when the merge replication load was high
Replication Snapshot
This counter group consists of two counters, Delivered Cmds/Sec and Delivered Trans/
Sec Delivered Cmds/Sec measures the number of commands per second delivered to
the Distributor and Delivered Trans/Sec measures the number of transactions per
second delivered to the Distributor
DMVs
DMVs were introduced with SQL Server 2005 There are few DMVs that are related to Replication The sys.dm_os_performance_counters DMV will list the performance counters with their current values By including a like operator to object_name field as listed here, you can view the current values for all replication counters and for their instances
SELECT *
FROM sys.dm_os_performance_counters
WHERE object_name LIKE '%replication%'
There are four DMVs that are related to replication They are sys.dm_repl_articles,
sys.dm_repl_schemas, sys.dm_repl_tranhash, and sys.dm_repl_traninfo You can use these
DMVs to gather information about replication
TesT Day Tip
When you need to select the monitoring option between Performance Monitor and Replication Monitor for replication, you need to choose
perfmon when you want to gather data for some duration Also, in
Replication Monitor you don’t have an option for logging data, which
is available with perfmon.
Trang 5Summary of Exam Objectives
In this chapter we discussed Replication in SQL Server 2008 We covered the roles
of Publisher, Subscriber, and Distributor There are three main different types of
replication, Snapshot, Transactional, and Merge We compare them with the features
and usages of each replication type Replication monitoring is important because
you need to monitor whether your replication is responding to your configurations
Exam Objectives Fast Track
Replication Scenarios
Publication consists of articles that are database objects that need to
Ü
publish
Distributor is responsible for distributing data between Publisher and
Ü
Subscriber
Subscriber can be considered as the end user who will receive the data of
Ü
the article that Publisher publishes
Replication Types
There are three main types of replication; Snapshot, Transactional, and
Ü
Merge replication are used in different situations
Peer-to-Peer Replication is a transactional replication that can be used
Ü
when you need to replicate the entire contents of the database With
SQL Server 2008, Peer-to-Peer Replication has the feature of conflict
resolution
Replication Configuration
You need to create an initial snapshot for all replications
Ü
All the main configuration for replication is almost identical; each has
Ü
minor changes
When you are configuring Peer-to-Peer Replication, first you have to
Ü
configure Transactional Replication and enable the Peer-to-Peer Replication