Oracle HTTP Server SSL Caching

5-12 Oracle Fusion Middleware Performance and Tuning Guide In addition, there are a few modules that register their hooks to do some work during the URL translation phase, which would add to the cost of request processing time. Example: mod_security, when enabled, has a cost of about 10 on CPU Cost per Transaction for the specweb benchmark. Again, you should enable only those modules that are required by your deployed applications to save CPU time.

5.5.4 Monitoring Oracle HTTP Server

Oracle Fusion Middleware automatically and continuously measures run-time performance for Oracle HTTP Server. The performance metrics are automatically enabled; you do not need to set options or perform any extra configuration to collect them. If you encounter a problem, such as an application that is running slowly or is hanging, you can view particular metrics to find out more information about the problem. In addition to the Fusion Middleware Control, Oracle HTTP Server also has Dynamic Monitoring Service DMS, which collects metrics for every functional piece. You can review these metrics as needed to understand system behavior at a given point of time. This displays memory, CPU information and the min, max, average times for the request processing at every layer in Oracle HTTP Server. The metrics also display details about load level, number of threads, number of active connections, and so on, which can help in tuning the system based on real usage. You can use Oracle Enterprise Manager or SpyServlet to monitor the metrics. See Chapter 4, Monitoring Oracle Fusion Middleware . Another way to view DMS metrics for OHS is shown in the following example: 1. cd INSTANCE_HOMEbin 2. .opmnctl metric op=query COMPONENT_NAME=component_name dmsarg=[name=OHSModulesmodule_name.c Examples: .opmnctl metric op=query COMPONENT_NAME=ohs1 dmsarg=[name=OHSModulesmod_cgi.c .opmnctl metric op=query COMPONENT_NAME=ohs1 dmsarg=[name=] Note: Fusion Middleware Control provides real-time data. For more information on using Fusion Middleware Control to view performance metrics for HTTP Server, see Monitoring Oracle HTTP Server Performance in Oracle Fusion Middleware Administrators Guide for Oracle HTTP Server. If you are interested in viewing historical data, consider using Grid Control. See Section 4.8, Oracle Enterprise Manager 11g Grid Control . 6 Oracle Dynamic Monitoring Service 6-1 6 Oracle Dynamic Monitoring Service This chapter provides an overview and features available in the Oracle Dynamic Monitoring Service DMS. ■ Section 6.1, About Dynamic Monitoring Service DMS ■ Section 6.2, DMS Availability ■ Section 6.3, DMS Architecture Overview ■ Section 6.4, Viewing DMS Metrics ■ Section 6.5, Accessing DMS Metrics with WLDF ■ Section 6.6, DMS Execution Context ■ Section 6.7, DMS Tracing and Events ■ Section 6.8, DMS Best Practices

6.1 About Dynamic Monitoring Service DMS

The Oracle Dynamic Monitoring Service DMS enables Oracle Fusion Middleware components to provide administration tools, such as Oracle Enterprise Manager, with data regarding the components performance, state and on-going behavior. Fusion Middleware Components push data to DMS and in turn DMS publishes that data through a range of different components. Specifically, DMS is used by Oracle WebCache, Oracle HTTP Server OHS, Oracle Application Development Framework ADF, WebLogic Diagnostic Framework WLDF, and JDBC. DMS measures and reports metrics, trace events and system performance and provides a context correlation service for these components.

6.1.1 Common DMS Terms and Concepts

This section defines common DMS terms and concepts related to the following: ■ DMS Tracing and Events ■ DMS Nouns ■ DMS Sensors

6.1.1.1 DMS Tracing and Events

Table 6–1 provides a list of DMS tracing and event terminology.