Ovirt 代码阅读分享
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Transcript of Ovirt 代码阅读分享
ovirt code reading share
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● jboss-as● ovirt-engine-backend● ovirt-engine-frontend
jboss-as
● an application server● implementing java ee spec
○ JSP (servlet)○ JAX-RS (rest api)○ EJB (serve business logic, persistent, transaction)○ 。。。
● each spec impl is modular via jboss as configuration file
----------------------------------------------------------------------------------------jboss-as
● jboss as confiuration file○ server
■ extensions● extension （define module）
■ profile● subsystem （module specific configuration）
■ socket-binding-group （bind interface config）
● configuration file is loaded by "jboss-modules" project
----------------------------------------------------------------------------------------jboss-as
ovirt 启动 jboss-as
● ./packaging/services/ovirt-engine/ovirt-engine.py start● 启动 jboss-as: java -D… -jar jboss-modules.jar -xxx -c ovirt-engine.xml
----------------------------------------------------------------------------------------jboss-as
ovirt-engine-frontend
● gwt rpc 框架:
------------------------------------------------------------------------ovirt-engine-frontend
● ovirt's implementation:
ServiceDefTarget
GenericApiGWTServiceAsync
RpcService
GenericApiGWTService GenericApiGWTServiceImpl
RpcServlet
GWT.create( GenericApiGWTService.class )
------------------------------------------------------------------------ovirt-engine-frontend
-----------------------------------------------------------------------ovirt-engine-frontend
GenericApiGWTServiceImpl
Backend
JNDI
GenericApiGWTServiceAsync
Frontend
VdcOperationManager
gwt-rpc
ovirt-engine-backend
ovirt backend architecture
------------------------------------------------------------------------ovirt-engine-backend
Backend（business logic）
rest api
database
vds broker
aaa
Frontend
。。。
ovirt backend logic start from EJB
● 寻找 javax.ejb 内的标签: @Local, @Singleton, @Startup …● 根据 @DependsOn({ “XXX" }) 先后加载● 加载时执行@PostConstruct标注的方法● example:
○ Backend.java○ InitBackendServicesOnStartupBean.java
------------------------------------------------------------------------ovirt-engine-backend
Backend business logic Services（EJB）
● AsyncTaskManager● ResourceManager● MacPoolManager● UserDomainsCacheManagerService● InMemoryLockManager● ...
------------------------------------------------------------------------ovirt-engine-backend
AsyncTaskManager
● what is async task?○ vdsm commands related to storage actions○ monitoring tasks from vdsm："vdsClient -s 0 getAllTasks"
● timely check if task finished
------------------------------------------------------------------------ovirt-engine-backend
ResourceManager
● manage cluster○ schedule update from each vdsm in cluster
● manage storage pool (data center)○ schedule update from each spm in data center
------------------------------------------------------------------------ovirt-engine-backend
InMemoryLockManager
● entry point to acquire command’s lock● hold all commands’s locks
------------------------------------------------------------------------ovirt-engine-backend
ovirt backend Command
● bll command○ what? take care of a business logic○ how? interact with DAO(db), backend service, vds command
● vds command○ simple: invoke vdsm API
------------------------------------------------------------------------ovirt-engine-backend
bll command’s basic flow
● canDoAction● executeCommand● endAction (may not execute if no task)
------------------------------------------------------------------------ovirt-engine-backend
bll command & async task
● invoke vds command that contains async task● get a task id and hand it to AsyncTaskManager● endAction() is called when task is done
------------------------------------------------------------------------ovirt-engine-backend
bll command & monitoring
● step & job● monitoring step & job
○ add step/job○ end step/job
● frontend fetch from db timely●
------------------------------------------------------------------------ovirt-engine-backend
end
