Rational ClearCase 服务进程学习.doc

ClearCase Server ProcessesClearCase is a distributed application. Many of its operations involve several hostcomputers and several server processes on each host. This section introduces theClearCase server processes.For the most part, these servers do not need to be explicitly configured, started,stopped, or managed. The information in this section is intended to help youunderstand status and error messages that may be generated by these servers, to accessserver logs, and to get a better idea of the role each server process plays in a ClearCasenetwork.Two server processes albd_server and admin_serverrun on every host that hasbeen configured to support local VOBs and views, regardless of whether any VOBs orviews have been created on the host. Other server processes are started as necessary tomanage any VOBs and views that reside on the host.Note: ClearCase LT clients cannot be configured with support for local VOBs or views.No ClearCase server processes run on a ClearCase LT client host or on a ClearCase hostthat has been configured with no support for local VOBs and views.ClearCase 服务器进程Clearcase是一个分布式的应用软件。它的大多数的操作涉及到一些服务器主机和在这些主机上的一些进程。这部分介绍ClearCase的服务器进程。对于大多数部分，这些服务不需要显示的被配置，启动，停止和管理。本章节的知识更有效的帮助你理解可能由这些服务引起的状态和错误的消息，访问服务日志，和得到更好的概念对于每个服务在ClearCase网络中所扮演的角色。两个服务器进程- albd_server 和admin_server-运行在已经被配置在支持本地VOBs和Views的每个主机上，而不管是否有任何VOBs或者Views已经被创建在主机上。其他的服务进程被作为管理任何VOBs和Views的必要而启动长驻在主机上。注意：ClearCase LT客户端对于支持本地的VOBs或者Views不能被配置，没有ClearCase的服务进程运行在ClearCase LT的客户主机或者在不支持本地的VOBs或者Views已经被配置的ClearCase的主机上。albd_serverThe albd_server handles a variety of tasks on hosts configured to support local VOBsand views:_ Starting and stopping other ClearCase services as needed._ Setting up network communications between ClearCase clients and servers._ Managing execution of tasks run by the ClearCase scheduler.Chapter 1 - ClearCase Network Planning and Administration 9_ Responding to requests for registry information on a ClearCase registry serverhost._ Responding to requests for licenses on a ClearCase license server host.(ClearCase LT does not use the albd_server in this way.)_ On UNIX hosts, responding to load-balancing queries from a remote clearmakeprocess. (This feature is not supported on ClearCase LT.)When you start ClearCase, the albd_server starts first, and runs with one of thefollowing user identities:_ root on UNIX_ The built-in LocalSystem identity on ClearCase LT on Windows_ A specially created privileged user account on ClearCase on WindowsWhen you stop ClearCase, the albd_server stops all ClearCase services on the host andthen exits.Note: On a ClearCase LT client or a ClearCase client configured without support forlocal VOBs and views, the albd_server is not installed, and there are no otherClearCase services to stop or start.When a client program wants to access a service (a VOB or view server, for example)on a ClearCase server host, it uses a remote procedure call (RPC) to send a request tothe albd_server process on that host. The albd_server starts the requested service if itis not already started, then issues a response telling the client the services port number.Thereafter, the client communicates directly with the specific service, withoutinvolving the albd_server.ClearCase services started by the albd_server generally run with the identity of theresource (VOB or view) owner on UNIX and with the identity of the albd_server onWindows.Port AssignmentThe albd_server listens for RPCs on a well-known port (port 371) that has beenreserved for it by the Internet Assigned Numbers Authority. ClearCase installationverifies that no other service uses this port for UDP or TCP communications. If aconflict is detected, we recommend that you modify the conflicting service to useanother port. If you cannot reconfigure or remove the conflicting service, you mustconfigure the albd_server to use a different UDP port._ On UNIX, edit the local hosts services database and/or the NIS services map.10 Administrators Guide: Rational ClearCase and Rational ClearCase LT_ On Windows, create the appropriate entry in thefile%SystemRoot%System32driversetcservices. (If there is no entry for thealbd_server in this file, it will use port 371.)Note: All albd_server processes in a community must use the same port number. If youchange the albd_server port assignment on any ClearCase host, you must change it onevery ClearCase host.The albd_server reads configuration file albd.conf during startup to determine whichservices to provide. Do not modify this file.Albd_serverAlbe_server在配置成支持本地Vobs和Views的主机上运行了多种任务。l 当需要的时候启动和停止其他的ClearCase服务l 在ClearCase的服务器和客户机间设置网络通信。l 管理ClearCase的调度程序任务的执行l 响应ClearCase的注册服务主机上的注册信息的请求l 响应ClearCase的License主机上的License请求（ClearCase LT不使用Albd_Server用这种方式）l 在Unix主机，响应远程的ClearMake进程的查询装载平衡（ClearCase LT不支持这种功能）当你启动ClearCase时，albe_Server首先被启动，并且以下面一种的用户身份运行。l 在Unix上的rootl 在Windows上ClearCase LT的内置本地系统身份l 在Windows上ClearCase特别创建的一个有特殊权利的用户帐号当你停止ClearCase，Albd_Server服务停止所有在主机上的其他的服务，然后退出。注意：如果ClearCase LT客户端或者ClearCase客户端的配置不支持本地VOBs和Views，那么这个服务将不被安装，因此就没有其他服务可以停止或启动。当一个客户端程序想访问ClearCase服务器主机上的一个服务（例如，VOBs或者Views），它使用远程程序调用对主机上的Albd_Server发送一个请求，如果这个请求服务没有运行，那么Albd_Server将启动它，然后给客户端一个回应，告诉它服务的端口号，其后，客户端就可以直接和特定服务进行通信，而不用涉及Albd_Server。ClearCase服务被Albd_Server启动，通常的又被在Unix主机上资源（VOBs和Views）的所有者的身份和在Windows的Albd_Serveer身份运行。端口分配Albd_Server监听RPC在一个众所周知的371端口，这个端口已经被Internet Assigned Numbers Authority.所保留，ClearCase安装检验这个端口没有被其他的服务以UDP或者TCP通讯的方式使用，如果冲突一旦被发觉，我们建议你使用冲突的服务使用其他端口号，如果你不能重新配置这个服务或者移除冲突的服务，你就得去配置Aldb_Server使用其他的UDP端口。l 在Unix机，编辑本地服务器的数据和/或NIS服务匹配l 在Windows机，创建一个合适的条目在 file%SystemRoot%System32driversetcservices.（如果对于Albd_Server在文件中没有条目，那么它就使用371端口）注意：所有的Aldb_Server的进程在通讯中必须使用相同的端口号。如果你改变了端口的配置在任何一台ClearCase主机上，你就得改变它在每一个主机的端口配置。Aldb_Server在启动的时候读取 albd.conf这个配置文件，用来决定提供哪些服务。不要修改此文件。admin_serverThe ClearCase administration server (admin_server) is invoked as needed by thehosts albd_server process. This short-lived server performs miscellaneousadministrative support functions:_ Retrieving server log files for display by the getlog command and the ClearCaseAdministration Console._ Retrieving and changing the local hosts ClearCase properties when requested bythe ClearCase Administration Console._ Moving registry files and reconfiguring clients if the host is a backup registryserver.Admin_ServerClearCase的管理服务当需要的时候由主机上的albd_Server进程调用。这个短期的服务完成各种各样的管理支持功能。l 显示回收服务的日志文件通过getlog命令在ClearCase的管理控制台l 回收和改变本地主机的ClearCase属性当ClearCase管理控制台发出请求的时候l 移动注册文件和重新配置客户端如果主机是备份注册服务器credmap_serverThe credentials mapping server credmap_server runs on any ClearCase host that isconfigured to support local VOBs and views. This server handles credentials mappingin environments where users access a common set of VOBs and views from both UNIXand Windows computers. For more information, see Credentials Mapping on page 56.credmapserver凭证映射服务器运行在被配置成支持本地VOBs和Views的任何ClearCase主机上。这个服务操作凭证在那些用户访问在Unix和Windows机器上的一个VOBs和Views的通用设置的环境。更多的信息，请参考凭证映射在56页。view_serverA view_server is a long-lived process that manages activity in a particular view. Aview_server is started by the hosts albd_server process whenever a client requestsaccess to a view. A view_server remains active until it is terminated by a cleartoolendview server command, a system shutdown, or an operating system commandthat terminates the view_server process.When it begins execution, a view_server reads configuration information fromthe .view file in the view-storage directory. Values in this file are established bymkview, chview, and similar commands. Do not modify this file with a text editor.View_Server一个View_Server是一个常驻进程，它管理者活动在指定的View。无论什么时候当客户端请求访问View的时候，View_Server就被主机的albd_Server进程启动。它一直保持激活状态除非通过一个服务器命令cleartool endview关闭它，或者系统关闭了，或者一个操作系统的命令关闭了view_Server这个进程。当它开始执行，view_Server读取配置信息从在view-storage目录下的.view文件。信息值通过mkview，chview和类似的命令在这个文件中创建，不要修改这个文件用文本编辑器。vob_serverFor each VOB, a long-lived vob_server process runs on the VOB host. The vob_servermanipulates data in the VOBs storage pools in response to requests from clientprocesses.The vob_server is the only process that ever creates or deletes VOB data containers;only the VOB owner or a privileged user can modify VOB data containers and storagepools. For more information, see The VOB Storage Directory on page 105.A vob_server process is started as needed by albd_server. It remains active until anyof the following events occur:_ The VOB is removed with the rmvob command._ ClearCase is stopped on the VOB server host._ The VOB server host is shut down and restarted.When it begins execution, the vob_server reads configuration information from the filevob_server.conf in the VOB storage directory. Values in this file are established by thevob_snapshot_setup utility and other commands. Do not modify this file.Vob_Server对于每个VOB，一个常驻vob_server的进程运行在VOB的服务器上。它操纵数据在VOBs存储池用来响应客户端进程的请求。Vob_server是一个唯一永远创建或者删除VOB数据的容器，只有VOB的属主或者有特殊权限的用户才能修改VOB数据容器和存储池。有关更多的VOB存储目录信息在105页。Vob_server进程当需要的时候被albd_server启动，它保持激活状态直道任何以下的事件发生：l VOB通过rmvob命令删除了l 在VOB服务器上的ClearCase被停止了运行l VOB服务器关闭和重启当它开始运行的时候，vob_server读取VOB storage目录下的vob_server.conf文件的配置信息。信息值通过vob_snapshot_setup和其他命令在这个文件中有效的创建。不要修改这个文件。db_serverA hosts db_server processes manage VOB database transactions on that host inresponse to requests from client programs. Because client programs cannot access VOBdatabases directly, they must send database transaction requests to a db_server processwhen they need to create, read, or modify VOB data or metadata.Each db_server process services a single client at a time, but can operate on anynumber of VOBs. A client establishes a connection to a db_server with the help of thealbd_server on the VOB host. If necessary, the albd_server starts a new db_serverprocess to handle a request. The connection is broken when the client exits or becomesidle (stops requesting database transactions for an extended period). At that point, thedb_server becomes available for use by another client. After a period of idleness, anunconnected db_server is terminated by its hosts albd_server.db_serverdb_server进程管理VOB数据库事务在那个响应客户端程序发送请求的主机上。因为客户程序不能直接访问VOB数据库，他们必须发送数据库事务请求给db_server进程当他们需要去创建，读取，或者修改VOB数据或者元数据。每个db_server进程服务在同一时间只服务单个客户端，但是可以操作任何数量的VOBs。客户端创建一个连接到db_server通过在VOB主机上的albd_server进程的帮助，如果有必要，albd_server启动一个新的db_server进程去操作请求。当客户端退出或者空闲（停止请求数据库事务由于延迟时间）的时候，连接将会被断开。在那种情况，db_server变得可用的被其他的客户端，当空闲一段时期后一个未连接的db_server将被那个主机的albd_server关闭。vobrpc_serverEach VOB server host runs one or more vobrpc_server processes for each of its VOBs.Each vobrpc_server process handles requests from view_server processes throughoutthe network. These requests can generate both metadata (VOB database) and filesystem data (storage pool) activity. The vobrpc_server accesses the VOB database inthe same way as a db_server; it forwards storage pool access requests to thevob_server.12 Administrators Guide: Rational ClearCase and Rational ClearCase LTvobrpc_server processes are started by albd_server, which also routes new requests tothe least-busy servers and terminates unneeded vobrpc_server processes when thesystem is lightly loaded.vobrpc_server每个VOB服务主机运行一个或更多的vobrpc_server进程对每个VOBS。每个vobrpc_server进程操作来自网络的view_server进程的请求。这些请求能生成元数据（VOB数据库）和文件系统数据（存储池）活动。Vobrpc_server访问VOB数据库德方式和db_server访问方式一