Tomcat MBean Names

Tomcat MBean Names

Background

We will be using JMX MBeans as the technology for implementing manageability of Tomcat. One of the key concepts of JMX (and JSR-77) is that each management bean has a unique name in the MBeanServer's registry, and that management applications can utilize these names to retrieve the MBean of interest to them for a particular management operation. This document proposes a naming convention for MBeans that allows easy calculation of the name for a particular MBean. For background information on JMX MBean names, see the Java Management Extensions Instrumentation and Agent Specification , version 1.0, section 6. In particular, we will be discussing the String Representation of ObjectName instances.

Catalina Object Hierarchy

Tomcat's servlet container implementation, called Catalina, can be represented as a hierarchy of objects that contain references to each other. The object hierarchy can be represented as a tree, or (isomorphically) based on the nesting of configuration elements in the conf/server.xml file that is traditionally used to configure Tomcat stand-alone. The valid component nestings for Catalina are depicted in the following table, with columns that contain the following values: Pattern - Nesting pattern of XML elements (in the conf/server.xml file) used to configure this component. Cardinality - Minimum and maximum number of occurrences of this element at this nesting position, which also corresponds to the minimum and maximum number of Catalina components. Identifier - Name of the JavaBeans property of this component that represents the unique identifier (within the nested hierarchy), if any. MBean ObjectName - The portion of the MBean object name that appears after the domain name. For now, it should be assumed that all of these MBeans appear in the default JMX domain. In the MBean ObjectName descriptions, several types of symbolic expressions are utilized to define variable text that is replaced by corresponding values: ${GROUP} - One of the standard MBean names of the specified "group" category. For example, the expression ${REALM} represents the values like JDBCRealm and JAASRealm that identify the various MBeans for possible Realm components. ${name} - Replaced by the value of property name from the current component. ${parent.name} - Replaced by the value of property name from a parent of the current component, with the parent's type identified by parent . ${###} - An arbitrary numeric identifier that preserves order but has no other particular meaning. In general, the server will assign numeric values to existing instances with large gaps into which new items can be configured if desired. Pattern Cardinality Identifier MBean ObjectName Server 1..1 (none) type=${SERVER} Server / Listener 0..n (none) type=${LISTENER}, sequence=${###} Server / Service 1..n name type=${SERVICE}, name=${name} Server / Service / Connector 1..n address, port type=${CONNECTOR}, service=${service}, port=${port}, address=${address} Server / Service / Connector / Factory 0..1 (none) (Only defined explicitly for an SSL connector, but can be treated as part of the connector component) Server / Service / Connector / Listener 0..n (none) type=${LISTENER}, sequence=${###}, service=${service}, port=${connector.port}, address=${connector.address} Server / Service / Engine 1..1 (none) type=${ENGINE}, service=${service.name} Server / Service / Engine / Host 1..n name type=${HOST}, host=${name}, service=${service.name} Server / Service / Engine / Host / Context 1..n path type=${CONTEXT}, path=${path}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Context / InstanceListener 0..n (none) type=${INSTANCE-LISTENER}, sequence=${###}, path=${context.path}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Context / Listener 0..n (none) type=${LISTENER}, sequence=${###}, path=${context.path}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Context / Loader 0..1 (none) type=${LOADER}, path=${context.path}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Context / Manager 0..1 (none) type=${MANAGER}, path=${context.path}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Context / Realm 0..1 (none) type=${REALM}, path=${context.path}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Context / Resources 0..1 (none) type=${RESOURCES}, path=${context.path}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Context / Valve 0..n (none) type=${VALVE}, sequence=${###}, path=${context.path}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Context / Wrapper 0..n (none) j2eeType=Servlet,name=${name}, WebModule=//${host.name}/${context.name}, J2EEApplication=${context.J2EEApplication}, J2EEServer=${context.J2EEServer} Server / Service / Engine / Host / Context / WrapperLifecycle 0..n (none) type=${WRAPPER-LIFECYCLE}, sequence=${###}, path=${context.path}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Context / WrapperListener 0..n (none) type=${WRAPPER-LISTENER}, sequence=${###}, path=${context.path}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Listener 0..n (none) type=${LISTENER}, sequence=${###}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Realm 0..1 (none) type=${REALM}, host=${host.name}, service=${service.name} Server / Service / Engine / Host / Valve 0..n (none) type=${VALVE}, sequence=${###}, host=${host.name}, service=${service.name} Server / Service / Engine / Listener 0..n (none) type=${LISTENER}, sequence=${###} (FIXME - disambiguate from Server / Service / Listener) Server / Service / Engine / Realm 0..1 (none) type=${REALM}, service=${service.name} Server / Service / Engine / Valve 0..n (none) type=${VALVE}, sequence=${###}, service=${service.name} Server / Service / Listener 0..n (none) type=${LISTENER}, sequence=${###} (FIXME - disambiguate from Server / Service / Engine / Listener)

MBean Groups and Names

The following MBean names shall be defined in the resource file /org/apache/catalina/mbeans/mbeans-descriptors.xml (and therefore available for use within the Administration/Configuration web application for Tomcat): MBean Name Group Name Catalina Interface Implementation Class AccessLogValve VALVE org.apache.catalina.Valve org.apache.catalina.valves.AccessLogValve BasicAuthenticator VALVE org.apache.catalina.Valve org.apache.catalina.authenticator.BasicAuthenticator CertificatesValve VALVE org.apache.catalina.Valve org.apache.catalina.valves.CertificatesValve ContextConfig LISTENER org.apache.catalina.LifecycleListener org.apache.catalina.startup.ContextConfig ContextEnvironment RESOURCES org.apache.catalina.deploy.ContextEnvironment org.apache.catalina.deploy.ContextEnvironment ContextResource RESOURCES org.apache.catalina.deploy.ContextResource org.apache.catalina.deploy.ContextResource ContextResourceLink RESOURCES org.apache.catalina.deploy.ContextResourceLink org.apache.catalina.deploy.ContextResourceLink CoyoteConnector CONNECTOR org.apache.catalina.Connector org.apache.coyote.tomcat4.CoyoteConnector DigestAuthenticator VALVE org.apache.catalina.Valve org.apache.catalina.authenticator.DigestAuthenticator EngineConfig LISTENER org.apache.catalina.LifecycleListener org.apache.catalina.startup.EngineConfig ErrorReportValve VALVE org.apache.catalina.Valve org.apache.catalina.valves.ErrorReportValve ErrorDispatcherValve VALVE org.apache.catalina.Valve org.apache.catalina.valves.ErrorDispatcherValve FormAuthenticator VALVE org.apache.catalina.Valve org.apache.catalina.authenticator.FormAuthenticator Group GROUP org.apache.catalina.Group org.apache.catalina.Group HostConfig LISTENER org.apache.catalina.LifecycleListener org.apache.catalina.startup.HostConfig HttpConnector10 CONNECTOR org.apache.catalina.Connector org.apache.catalina.connector.http10.HttpConnector HttpConnector11 CONNECTOR org.apache.catalina.Connector org.apache.catalina.connector.http.HttpConnector JAASRealm REALM org.apache.catalina.Realm org.apache.catalina.realm.JAASRealm JDBCRealm REALM org.apache.catalina.Realm org.apache.catalina.realm.JDBCRealm JDBCUserDatabase USERDATABASE org.apache.catalina.users.JDBCUserDatabase org.apache.catalina.users.JDBCUserDatabase JNDIRealm REALM org.apache.catalina.Realm org.apache.catalina.realm.JNDIRealm MBeanFactory org.apache.catalina.mbeans.MBeanFactory MemoryRealm REALM org.apache.catalina.Realm org.apache.catalina.realm.MemoryRealm MemoryUserDatabase USERDATABASE org.apache.catalina.users.MemoryUserDatabase org.apache.catalina.users.MemoryUserDatabase NamingContextListener LISTENER org.apache.catalina.LifecycleListener org.apache.catalina.core.NamingContextListener NamingResources RESOURCES org.apache.catalina.deploy.NamingResources org.apache.catalina.deploy.NamingResources NonLoginAuthenticator VALVE org.apache.catalina.Valve org.apache.catalina.authenticator.NonLoginAuthenticator PersistentManager MANAGER org.apache.catalina.Manager org.apache.catalina.session.PersistentManager RemoteAddrValve VALVE org.apache.catalina.Valve org.apache.catalina.valves.RemoteAddrValve RemoteHostValve VALVE org.apache.catalina.Valve org.apache.catalina.valves.RemoteHostValve RequestDumperValve VALVE org.apache.catalina.Valve org.apache.catalina.valves.RequestDumperValve Role ROLE org.apache.catalina.Role org.apache.catalina.Role SingleSignOn VALVE org.apache.catalina.Valve org.apache.catalina.valves.SingleSignOn SSLAuthenticator VALVE org.apache.catalina.Valve org.apache.catalina.authenticator.SSLAuthenticator StandardContext CONTEXT org.apache.catalina.Context org.apache.catalina.core.StandardContext StandardContextValve VALVE org.apache.catalina.Valve org.apache.catalina.core.StandardContextValve StandardEngine ENGINE org.apache.catalina.Engine org.apache.catalina.core.StandardEngine StandardEngineValve VALVE org.apache.catalina.Valve org.apache.catalina.core.StandardEngineValve StandardHost HOST org.apache.catalina.Host org.apache.catalina.core.StandardHost StandardHostValve VALVE org.apache.catalina.Valve org.apache.catalina.core.StandardHostValve StandardManager MANAGER org.apache.catalina.Manager org.apache.catalina.session.StandardManager StandardServer SERVER org.apache.catalina.Server org.apache.catalina.core.StandardServer StandardService SERVICE org.apache.catalina.Service org.apache.catalina.core.StandardService StandardWrapper WRAPPER org.apache.catalina.Wrapper org.apache.catalina.core.StandardWrapper StandardWrapperValve VALVE org.apache.catalina.Valve org.apache.catalina.core.StandardWrapperValve User USER org.apache.catalina.User org.apache.catalina.User UserDatabaseRealm REALM org.apache.catalina.Realm org.apache.catalina.realm.UserDatabaseRealm WebappLoader LOADER org.apache.catalina.Loader org.apache.catalina.loader.WebappLoader

JSR-77 Cross Reference

The managed objects in the JSR-77 object hierarchy correspond to the specified MBean names or groups as follows: JSR-77 Managed Object MBean Name or Group Comments J2EEServer ${SERVICE} Node ${SERVICE} Tomcat supports a single node only. Port ${CONNECTOR} Servlet ${WRAPPER} WebModule ${CONTEXT}

JSR-88 Cross Reference

The deployment objects in the JSR-88 API object hierarchy correspond to the specified MBean names or groups as follows: JSR-88 API Object MBean Name or Group Comments DeployableObject ${CONTEXT} Context deployment info plus the corresponding WAR file Target ${HOST}