In this full URL we actually specify the host where the Tomcat process is located and it's port. Had the two Tomcat processes run on the same machine, we would have to configure each of them with different connector ports. For example, assuming that the two JVMs runs on localhost, the Apache-Tomcat configuration should have something that looks like:. Looking at the above file you can see that we have two explicit ApJServ mount points each pointing to a different port on the same machine.
It is clear that this configuration requires support from the configuration found in the server. We will actually need two different server. The port configuration is not the only place where the joe and bill configuration differs. We have marks in the xml files marking the four places where changes had to be made. As you can see, this difference is necessary to avoid the two Tomcat processes from overwriting each other's logs and workspace.
It is possible to support virtual hosts under Tomcat Ver3. With the current Ver3. The web server virtual hosting support is used by the Tomcat adapter to redirect requests belonging to a certain virtual host to the JVM s containing the contexts of this virtual host.
This means that if for example we have two virtual hosts vhost1 and vhost2 , we will have two JVMs: one running the contexts of vhost1 and the other running the contexts of vhost2. These JVMs are not aware of each others existence, in fact, they are not aware of the concept of virtual hosting. All the virtual hosting logic is inside the web-server adapter. To make things clearer, lets look at the following sample Apache-Tomcat configuration file:. The configuration of the two JVMs is very similar to the one demonstrated in the previous section, we will need again to use two different server.
After doing that we will be able to approach Apache, each time with a different host name, and the adapter will redirect us to the appropriate JVM.
The need for improved virtual host support Having each virtual host implemented by a different JVM is a huge scalability problem. The next versions of Tomcat will make it possible to support several virtual hosts within the same Tomcat JVM. By default the Tomcat distribution comes with a naive configuration whose main goal is to promote first time user experience and an "out of the box" operation This configuration however is not the best way to deploy Tomcat on real sites.
For example, real sites may require some performance tuning and site-specific settings additional path elements for example. This section will try to get you started by directing you to the first steps that should be taken before publishing a Tomcat based site. As stated in the previous sections, the startup scripts are here for your convenient. Yet, sometimes the scripts that are needed for deployment should be modified:. On UNIX you can also create a file named ". There are a few things that you should consider to improve your Tomcat performance:.
The Connectors, as configured in Tomcat's default server. Tomcat is a multi-threaded servlet container this means that each request needs to be executed by some thread.
Prior to Tomcat 3. This behavior is problematic for loaded sites because:. The solution for these problems is to use a thread pool , which is the default for Tomcat 3. Servlet containers that are using a thread pool relieve themselves from directly managing their threads. Instead of allocating new threads; whenever they need a thread they ask for it from the pool, and when they are done, the thread is returned to the pool.
The thread pool can now be used to implement sophisticated thread management techniques, such as:. You can refine the techniques described above in various ways, but these are only refinements. The main contribution of thread pools is thread-reuse and having a concurrency upper bound that limits resource usage. For example the following server. The default configuration is suitable for medium load sites with an average of concurrent requests. If your site differs you should modify this configuration for example reduce the upper limit.
Servlet auto-reloading is really useful for development time. However it is very expensive in performance degradation terms and may put your application in strange conflicts when classes that were loaded by a certain classloader cannot co-operate with classes loaded by the current classloader.
So, unless you have a real need for class reloading during your deployment you should turn off the reloadable flag in your contexts. Contains various configuration files including server.
Contains various jar files that are used by Tomcat. The servlet APIs source files. Don't get excited, though; these are only the empty interfaces and abstract classes that should be implemented by any servlet container. Automatically generated by Tomcat, this is where Tomcat places intermediate files such as compiled JSP files during it's work.
If you delete this directory while Tomcat is running you will not be able to execute JSP pages. You can create this directory to add additional classes to the classpath. Any class that you add to this directory will find it's place in Tomcat's classpath. The main script. Executes java with command line parameters that set up a java system environment, called tomcat.
Tomcat as the startup class. It also passes command line parameters to org. A path to the server. If not possible, the following jar files are included statically: ant.
The topmost element in the file server. This element defines a logger object. These interceptors listen for certain events that happen in the ContextManager. The Connector represents a connection to the user, either through a web server or directly to the user's browser in a stand-alone configuration. The Team behind Apache Tomcat note that: The Apache Tomcat project is intended to be a collaboration of the best-of-breed developers from around the world…Apache Tomcat software powers numerous large-scale, mission-critical web applications across a diverse range of industries and organizations.
Poll Privacy Policy As Mulesoft notes however, it ships with fairly pared back administrative capabilities and tooling. Join Our Newsletter Want more on technology leadership? Sign up for Tech Monitor's weekly newsletter, Changelog, for the latest insight and analysis delivered straight to your inbox. White papers Home About us Contact us Newsletter. White papers from our partners. Users rarely create custom Hosts because the StandardHost implementation provides significant additional functionality.
A Connector handles communications with the client. There are multiple connectors available with Tomcat, all of which implement the Connector interface. Creating a customized connector is a significant effort. A Context represents a web application. A Host may contain multiple contexts, each with a unique path.
The Context interface may be implemented to create custom Contexts, but this is rarely the case because the StandardContext provides significant additional functionality. Tomcat is designed to be a fast and efficient implementation of the Servlet Specification. Tomcat came about as the reference implementation of this specification, and has remained rigorous in adhering to the specification.
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