Passa ai contenuti principali

Tomcat Manager Configuration

This tutorial shows how to configure the tomcat manager application that can be used to administrate Tomcat. We will also show how to enable the default user and password and how to grant the roles required to run the manager application.
The Tomcat Manager is a very powerful tool for Tomcat administration. It allows you to use the following features:

  • Remote application deployment 
  • Cleanup of Idle session
  • Application undeployment and redeployment
  • Analysis of memory leaks
  • JVM status
  • Server status

The Tomcat Manager by default is disabled in Tomcat 7. In order to enable it, pickup the tomcat-users.xml in the conf folder of Tomcat 7. This file contains two users: tomcat and role1. These roles however are not enabled to use the manager gui, as you need an user with the "manager-gui" roles. So change the file so that it look like this:

<tomcat-users>
 

<role rolename="manager-gui"/>
<user username="tomcat" password="s3cret" roles="manager-gui"/>
 
</tomcat-users>

Logging into the Manager with the default username and password

So now with the above changes, you will be able to login into Tomcat Manager application with Tomcat manager-gui user name and password that is tomcat/s3cret.



Through this console, we can deploy new applications or modify the current application's state to stop, undeploy, start, reload, clear sessions, and so on as displayed by the following picture:

Checking Tomcat Status


One interesting feature of Tomcat Manager is the ability to inspect the the current status of the server by clicking on the Server Status, as shown in the following picture:

The server status UI will show the following details:

  • JVM status (Max memory, Total memory, Free memory)
  • Connection of AJP port 8009  (Connection state, Data sent, Data received, Client, Virtual host)
  • Connection on HTTP port 8080 (Connection state, Data sent, Data received, Client, Virtual host)
  • Server information (Tomcat version, OS version, JVM version, System architecture)

Commenti

Post popolari in questo blog

Tomcat maxThreads configuration

Tomcat maxThreads represents the maximum number of request
processing threads to be created by the HTTPConnector.

<Connector port="8443" protocol="org.apache.coyote.http11.Http11Protocol" maxThreads="250" SSLEnabled="true" scheme="https" secure="true" clientAuth="false" sslProtocol="TLS" connectiontimeout="20000"/> This determines the maximum number of simultaneous requests that can be handled. If not specified, this attribute is set to the default value of 200.

How the process works:
At server startup, the HTTP Connector will create a number of processing threads based on the value configured for the minSpareThreads attribute. Each incoming request requires a thread for the duration of that request. If the number of simultaneous requests cannot be handled by the currently available request processing threads, additional threads will be created up to the configured maximu…

Tomcat Websocket example

A WebSocket is a full-duplex communication mechanism that allows both textual and binary messages to be sent between clients and servers, without the HTTP request/response life cycle. WebSockets allow either the client or the server to send a message at any time, providing an asynchronous solution for working with data while the user is performing a task.
Websockets API are included in Tomcat 7 Web server distribution so you don't have to download any extra library:

In this tutorial we will show how to create a WebSocket example using Apache Tomcat and Eclipse.
Start by creating on Eclipse a new Dynamic project named websocket-example:
We will now create a server side class named WebSocketDemo that is going to echo messages from a Javascript client:
package com.sample;import java.io.IOException;import java.nio.ByteBuffer;import javax.websocket.OnMessage;import javax.websocket.Session;import javax.websocket.server.ServerEndpoint; @ServerEndpoint("/echo") publicclass WebSoc…

Tomcat Thread Pool configuration

In order to accept incoming requests, Tomcat uses a Thread pool. You can configure two types of Thread Pools: Shared Pool and Dedicated Pool.
A Shared pool as the name inplies, can be shared among various components in Tomcat. So, for example if you have three connectors in your configuration, then you can use a single shared pool to serve requests for all of them. Here is how to configure a shared thread pool:

Open Tomcat's server.xml file and include the Executor definition:

namePrefix="catalina-exec-" maxThreads="150" minSpareThreads="4"/>
Once you have added the shared thread pool, you need to reference it in your Connector configuration as follows:
namePrefix="catalina-exec-" maxThreads="200" minSpareThreads="4"/>
A Dedicated threadpool is a thread pool which is dedicated to only one connector definition. You can use it in a scenario when you are expecting a peak of connections and you want to have ful…