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Performance Tuning in the Tomcat Server

Performance tuning of an Apache Tomcat Server is considered a bit of a black art and something that only an experienced Tomcat admin should undertake.  While expertise with Tomcat and best practices for its implementation/management is important, there are some basic tuning approaches you can employ that will provide significant benefits for little effort.  This article covers those approaches.

 

Spend some time understanding the installation of Tomcat, the web site's traffic level, and the web applications that it runs.  In general Tomcat performs better when you:

 

- Start the JVM with its initial heap tomcat memory size (the -Xms switch) set to the maximum memory size.  Using the maximum setting, the JVM never needs to resize and reallocate the heap memory while trying to serve requests.

 

- Start the tomcat JVM with a higher heap memory maximum using the -Xmx switch.  The higher this setting, the more memory is available, allowing the server a higher percentage of its CPU time to serve web requests.  If your webapp runs on dedicated server hardware, give the JVM as much of the machine's physical memory as reasonably possible.  If it is running on shared or virtual hardware, hook up a console (such as Tcat Server console) to see how much memory your webapp uses under high load circumstances and adjust the maximum heap size accordingly.

 

- Tweak the Connector (web server) thread pool settings for your web request load based on your peak traffic patterns. If the maxThreads attribute is set too low, you may not have enough threads to handle all of the requests causing requests to sit idle until another request thread is freed up to handle them, and Tomcat will be unable to take advantage of your server's hardware.  If the maxThreads attribute is set too high, Tomcat startup time will increase, and can slow down your server during peak load periods trying to run a high number of request threads concurrently.

 

- Additional Connector attribute settings:

* compression: Toggle between "on" and "off" to determine which setting is best for your webapp.

* compressableMimeTypes: If you enable compression, set this attribute to show Tomcat what you want it to compress.  Try something like "text/html,text/xml,text/javascript,text/css,text/plain".

 

Other important factors in performance tuning include:

- HTTP caching headers: Enabling the user's web browser to cache the static content of your webapps can greatly increase the user's perceived performance.  It is important to set the right set of response headers and their values when Tomcat serves the webapp's static files. Proxying all requests to Tomcat from Apache HTTPD is not advised for maximum Tomcat performance as that configuration may cause a loss of about half of the Tomcat's performance.

 

- HTTPS is slower than HTTP.  Bringing the Tomcat server geographically closer to the users may help reduce request times.

 

- Many webapps use a relational database, making the database connection settings very important.  Adjust the maxActive, maxIdle, and maxWait attributes where you define your database connection.

 

If using the AJP Connector, set the attribute request.registerRequests="false" to stop logging tomcat JMX stats for the requests of the connector, to make performance steadier during traffic spikes.

 

 

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For more information please click here tomcat admin and  tomcat jvm

 

How to connect a firewire header to a motherboard?

I have a computer case that has a front ieee 1394 header and a motherboard that doesn't have a ieee 1394 connector.Is there a way to connect them both?

motherboard

http://www.newegg.com/Product/Product.aspx?Item=N82E16813121323

case

http://www.newegg.com/Product/Product.aspx?Item=N82E16811108052

You will need to buy a PCI-FireWire card.

Many cards have an internal connector in addition to the ones that go out to the rear of the PC - you want one of those.

http://www.newegg.com/Product/Product.aspx?Item=N82E16815124003

You will need to figure out how to connect the cable from the front of the enclosure to this card - hopefully it's not too hard.

Build Your Own PC: Step 8 - Attach ATX Power Connector & Header Cables