A live production database server will typically receive concurrent SQL traffic from several application servers, each of which may exist in a number of permutations of client libraries and versions, along with a varying & unpredictable component of ad hoc traffic from tools such as Toad, iSQL, and Microsoft Excel – again in rapidly multiplying permutations.
|iReplay Core Components|
|iReplay Server||Handles pre/post-processing and Replay runs. Linux only; dedicated Linux host or Linux-based capture appliance recommend. Intel Xeon Dual socket with at least 12 GB RAM recommended.|
|iReplay Report Server||Report Generation Only; Linux host, may reside on same host as main iReplay Server.|
|iReplay Client||Windows GUI. Install on any windows workstation. Included with iReplay Server License.|
Efforts to duplicate this level of complexity in a lab environment usually fall short. Either the lab team must re-create all of the permutations of client libraries, or it will strip out this very significant complexity for the sake of convenience, creating something that is easy to implement, but – in the manner of high-school science problems – sufficiently divorced from reality to call into question any subsequent findings (“Assume a spherical cow of uniform density…”). iReplay solves this problem by intelligently re-processing raw network traffic, allowing a single iReplay server to accurately reproduce the complexity and concurrency of your original SQL load, just as if it had originated from your original mix of applications and client libraries.
This means that there is no need to duplicate application servers or client libraries in your lab environment; you need only duplicate the database instance itself, and bring it into the same state as existed at the start of the capture process. In addition to a test version of your database server, you will need the iReplay software components as outlined in the tables below & above right.
|iReplay Capture Options|
|iCapture (on host)||Easiest to install; suitable for most installations. Install directly on the source & target hosts; No taps or network configuration required. Minimal overhead (2-3% CPU Core); Available for Linux, AIX, Solaris and Windows hosts.|
|iCapture (via Network Tap)||Recommended whenever it is not practical to install the capture utility directly on the database host. Install on a separate Linux host in the same subnet, using a network tap or optical splitter. May co-reside with the iReplay Server|
|Capture Appliance (via Network Tap)||For capturing very high throughput workloads (10 Gigabit/sec or higher). Requires network tap or optical splitter, but no software to install on the database host.|
|iCapture-ng (via Network Tap)||For capturing high throughput workloads (up to 10 Gigabit/sec). Requires network tap or optical splitter, but no software to install on the database host. Install on a separate Linux host in the same subnet. May co-reside with the iReplay Server.|
Next Section : iReplay Database & Platform Support