CHAPTER 10 JAVA EE PERFORMANCE (Web site hosting) ASSESSMENT
CHAPTER 10 JAVA EE PERFORMANCE ASSESSMENT SUPPORTS: If this method is invoked inside a transaction context, then it will participate, but it is not required to run inside a transaction context. NOT_SUPPORTED: This method does not participate in transactions, so if it is invoked by a method currently running inside a transaction, that transaction is suspended while this method runs. NEVER: This method will never run inside a transaction. Furthermore, if you call it from a method currently running in a transaction, then this method will throw an exception. When transactions occur, either they can be committed or they can fail and roll back. From an analysis perspective, we look at commit rates, rollback rates, and the nature of rollbacks. Rollbacks can come in one of several forms, defined as follows: Application rollbacks: An application transaction has failed; this can be a normal function of the application. For example, an application that processes a survey may roll back a transaction if the user submitting the transaction is under 18 years old. System rollbacks: Something very bad happened in the application server, such as a hardware failure that causes the application server to stop responding. Resource rollbacks: A resource somehow failed for example, the application server attempts to renew a database connection and cannot connect to the database. Time-out rollbacks: A request took too long to process, so the application server killed it and threw a time-out exception. In a performance analysis report, these metrics are interpreted as follows: If the percentage of transactions rolled back is greater than 10 percent, then issue a critical alert. If a nonapplication rollback occurs, issue a fatal alert. Application Analyzing the performance of an application involves identifying slow service requests and then triaging and isolating their root causes, which we look at in the sections that follow. Identifying Slow Service Requests The first step is to identify slow-running service requests, which come in three flavors: Service requests that average slow response times Service requests that average acceptable response times, but experience periodic spikes in response time Service requests that average acceptable response times, but significantly impact the system due to the sheer number of times they are called Your monitoring tool should provide the following information for each aggregated sample for each request that it observes during a test:
You need excellent and relaible webhost company to host your web applications? Then pay a visit to Inexpensive Web Hosting services.