A tier is a logical application layer or a representation of a fragment of your monitored environment. The tier definition simply describes the global sequence of tiers. This global definition, when applied to a specific application, shows the appropriate sequence of tiers for that application.
A tier is not a filter on software services. It is a collection of one or more software services or transactions. You configure tiers globally. Do not create separate tiers for individual applications. To see the layered view for a specific application, configure that application and its transactions on the NAM Server.
A front-end tier is the layer closest to the end user.
- A front-end tier always exists as a part of an application defined on the NAM Server.
- The front-end tier definition helps you set a logical pattern to the physical location of Dynatrace measuring points; you can clearly differentiate between your end users and your data center.
- By defining more than one front-end tier for an application, you can add a clearer perspective to the user side because users can be classified based on the way they approach your application.
With the default configuration, soon after the NAM Server is deployed, tiers based on HTTP, HTTPS, Oracle Forms, SAP, and Exchange analyzers are always the front-end tiers for a given application. By default, the following tiers are categorized as front-end:
- RUM sequence transactions
- RUM Browser
- Oracle Forms
If you have any other tier in front of the Web servers, and it is not a presentation server, such as Citrix or Windows Terminal Services, mark that tier as a front-end.
Generally, mark a tier as a front-end which is the closest to the user or to a device that acts on behalf of the user. This is the first layer with which a user connects.
There is an exception to this rule. If you use presentation servers such as Citrix or Windows Terminal Services do not treat them as your front-end. Treat them as a client that connects with the first application layer. The following figure is an example of using a presentation server. Note that the front-end tier in this case is the HTTP layer (Web server).
After the NAM Server is installed and deployed, there are several default tiers.
Default tiers have assigned rules and cannot be modified by the user. The rules are based on the type of monitored traffic (analyzer type). This is the most universal solution. The data is measured at various points, and is classified by type and presented as layers. With this automatic configuration, you can instantly monitor various points either within your network or at client locations. You can also create transactions and applications on the NAM Server and apply an additional, business perspective to the observed traffic.
Logical front-end tier assignment
Front-end tiers play an important role for your applications defined on the NAM Server. They are displayed on the Applications report; to see all tiers for a given application, navigate to the Tiers report for that application). This enables you to quickly review all the layers closest to your end users.
You can assign a logical front-end tier through Business units (on the NAM Server navigation menu, select APM model ► Business units).
Users using the same application can use different methods to access its resources. For example, two end users may be using the same application server; however, one approaches from the Internet and the data travels through a web server, while the other accesses the application server directly with a dedicated client or web service. In the first case, the web server is a front end for your application; in the second case, the application server itself is the front end.
Example front-end tiers for an application:
Front-end tiers for application
While configuring tiers, you can indicate which tiers will be regarded as front-end. This configuration is global for all applications.
If there is any traffic detected on a front-end tier and the traffic matches your application definition, you will be able to see measurements for that tier and for that application on the Applications report. Note that it is possible for a single application to have more than one front-end tier.
For example, there may be two front-end tiers that match your application. The first tier is based on transactions originating from Enterprise Synthetic agents, referred to as Synthetic . The second tier is based on sequence transactions, referred to as RUM sequence transactions .
If traffic is detected on both front-end tiers for your application in the last monitoring interval:
In the Application column, you will see two rows with your application name. This is because there is data for both front-end tiers for your application.
In the Tier column, you will see both front-end tiers for your application: Synthetic and RUM sequence transactions next to your application name displayed in the Application column.
Default configuration of tiers
The default configuration is read during the first NAM Server startup. The default tier definitions are based on analyzer types, transactions, or sites.
The default configuration is immediately affected by the types of data collectors connected to the NAM Server and by the types of software services defined. This means that the Tiers report will display only those tiers that match the data detected in the monitored traffic.
Synthetic, matching all traffic coming from Enterprise Synthetic agents.
RUM sequence transactions, matching all sequence transactions defined on the NAM Probe.
Client network, matching all traffic for client sites, except the All Other site.
Client optimized network, matching network accelerated environment traffic.
Citrix/WTS (presentation), based on the ICA analyzer.
Network, matching all traffic for the All Other site.
Website, based on the Web analyzer group, including HTTP, SSL, and Oracle Applications analyzers.
Oracle Forms, based on the Oracle Forms analyzer group.
SAP, based on the SAP analyzer group.
Exchange, based on the Exchange analyzer.
Middleware, based on the Jolt (Tuxedo) analyzer group, including Jolt, XML, SOAP and SAP RFC analyzers.
Message Queue, based on the IBM MQ analyzer.
Database, based on the Database analyzer group, including Oracle, Informix, TDS, and DRDA (DB2) analyzers.
Data center infrastructure, based on the Datacenter analyzer group, including DNS, Generic (with transactions), ICMP, IP, NetFlow, Non IP, SMB, SMTP, and UDP analyzers.
If the default configuration does not fit your network architecture, you can change the definition of the Client network and Network tiers using Business units (on the NAM Server navigation menu, select APM model ► Business units).
Use the Client network and Network tiers to separate the client traffic from the data center traffic. To do this, you must configure the Client network tier manually.
Consider the following when configuring tiers:
Each tier is described by its name and the sequence number.
You will not see the sequence numbers on the Tiers report. Sequence numbers help to display the layers on the report in the correct order, which you define while configuring tiers.