When you examine performance, a number of factors influence how much capacity a given hardware configuration will need in order to support WebLogic Server and a given application. The hardware capacity required to support your application depends on the specifics of the application and configuration. You should consider how each factor applies to your configuration and application. Before continuing with this section, here are some recommended starting points for planning your hardware configuration:
- BEA WebLogic Server Capacity Planning Guide is a guide for capacity planning efforts for enterprise-level solutions built with WebLogic Server, with a focus on server hardware requirements.
- The Standard Performance Evaluation Corporation provides a set of standardized benchmarks and metrics for evaluating computer system performance.
The following table provides some links to the information on the Supported Configurations pages, which contains the latest certification information on the hardware/operating system platforms that are supported for each release of WebLogic Server.
Tune your operating system according to your operating system documentation. BEA certifies WebLogic Server on multiple operating systems on the Supported Configurations pages.
For Windows platforms, the default settings are usually sufficient. However, the Solaris and Linux platforms usually need to be tuned appropriately.
Setting TCP Parameters With the ndd Command
Set the following TCP-related tuning parameters using the ndd
command, as demonstrated in the following example:
ndd -set /dev/tcp tcp_conn_req_max_q 16384
Suggested Value | |
Note: Prior to Solaris 2.7, the tcp_time_wait_interval
parameter was called tcp_close_wait_interval
. This parameter determines the time interval that a TCP socket is kept alive after issuing a close call. The default value of this parameter on Solaris is four minutes. When many clients connect for a short period of time, holding these socket resources can have a significant negative impact on performance. Setting this parameter to a value of 60000 (60 seconds) has shown a significant throughput enhancement when running benchmark JSP tests on Solaris. You might want to reduce this setting further if the server gets backed up with a queue of half-opened connections.
Tip: Use the netstat -s -P tcp
command to view all available TCP parameters.
Setting Parameters In the /etc/system File
Each socket connection to the server consumes a file descriptor. To optimize socket performance, you need to configure your operating system to have the appropriate number of file descriptors. Therefore, you should change the default file descriptor limits, as well as the hash table size and other tuning parameters in the /etc/system
file, to the recommended values in the following table.
Note: You must reboot your machine anytime you modify /etc/system
parameters.
Suggested Value | |
Note: This should only be set for machines that have at least 4 GB RAM or higher. |
|
Network performance is affected when the supply of resources is unable to keep up with the demand for resources. Today’s enterprise-level networks are very fast and are now rarely the direct cause of performance in well-designed applications. However, if you find that you have a problem with one or more network components (hardware or software), work with your network administrator to isolate and eliminate the problem. You should also verify that you have an appropriate amount of network bandwidth available for WebLogic Server and the connections it makes to other tiers in your architecture, such as client and database connections. Therefore, it is important to continually monitor your network performance to troubleshoot potential performance bottlenecks.
A common definition of bandwidth is “the rate of the data communications transmission, usually measured in bits-per-second, which is the capacity of the link to send and receive communications.” A machine running WebLogic Server requires enough network bandwidth to handle all WebLogic Server client connections. In the case of programmatic clients, each client JVM has a single socket to the server, and each socket requires dedicated bandwidth. A WebLogic Server instance handling programmatic clients should have 125-150 percent of the bandwidth that a similar Web server would handle. If you are handling only HTTP clients, expect a bandwidth requirement similar to a Web server serving static pages.
To determine whether you have enough bandwidth in a given deployment, you can use the network monitoring tools provided by your network operating system vendor to see what the load is on the network system. You can also use common operating system tools, such as the netstat
command for Solaris or the System Monitor (perfmon
) for Windows, to monitor your network utilization. If the load is very high, bandwidth may be a bottleneck for your system.
Also monitor the amount of data being transferred across the your network by checking the data transferred between the application and the application server, and between the application server and the database server. This amount should not exceed your network bandwidth; otherwise, your network becomes the bottleneck. To verify this, monitor the network statistics for retransmission and duplicate packets, as follows:
For instructions on viewing other TCP parameters using the netstat -s -P
command, see Setting TCP Parameters With the ndd Command.
Your local area network must be fast enough to handle your application’s peak capacity. If your network is fully utilized, in that the amount of traffic consistently exceeds its bandwidth capacity, yet your WebLogic Server machine is not fully utilized, do one of the following:
- Redesign the network and redistribute the load.
- Reduce the number of network clients.
- Increase the number of systems handling the network load.