1. What is Dubbo
Dubbo Alibaba in 2011 revenue distributed service framework, the framework is the core service of governance. Dubbo mainly provides three functions, remote interface calls, load balancing and fault tolerance, service registration and service discovery
At present, the Apache open source project
Official website:
http://dubbo.apache.org
2, Dubbo architecture
3, details of the work instructions (from dubbo official website)
Role Description node (master)
Number of calls to the service provider Consumer Provider exposed service calls Remote Registry service consumer services registered with the service registry Monitor statistical services and found time to call the monitoring center run container Container Service
Call relationship Description
1. The service container is responsible for starting, load, run service provider. 2. The service provider when you start, registration services they provided to the registry. 3. Consumer Services at startup, you need to subscribe to the service registry. 4. The registry returns a list of addresses service providers to consumers, if there is a change, the registry will change based on the long connection push data to the consumer. 5. service consumers, providers from the list of addresses, soft load balancing algorithm, choose a provider call, if the call fails, then select another call. 6. service consumers and providers, in memory of the cumulative number of calls and call time, time sent once per minute statistical data to the monitoring center.
Dubbo architecture has the following characteristics
Connectivity
· Registration and lookup registry responsible for the service address, the equivalent of directory services, service providers and consumers interact with only registry, the registry does not forward the request at startup, less pressure-control center responsible for statistics the number of times each service call, call time, the statistics first time sent after the memory aggregated per minute to the monitoring center server, and to report to show · service providers to register their services provided to the registry, and report the call time to the monitoring center, this time does not include network overhead · consumer access to the service registry service provider address list, and call the provider directly from the load algorithms, time to call the monitoring center to report, this time includes network cost-registry, service providers, service consumers of the three inter are a long connection, control centers except center-registered through a long connection to sense the presence of the service provider, the service provider is down, the registry will immediately notify the consumer-push event registration center and all the monitoring center downtime, does not affect the already runs providers and consumers, consumers in this · Cache provider list and registry monitoring center are optional, serving consumers directly connected to the service provider
State of health
· Monitoring center shoot down does not affect the use, but the loss of part of the sampling data · Database after dawdle away, can still provide service registry list queries by caching, but you can not register the new service-peer cluster registry, after Renyiyitai dawdle away, after automatically switch to another-all shoot down the registry, service providers and service consumers can still stateless communication via local cache-service provider, after Renyiyitai shoot down, does not affect all service providers · after the shoot down, the service consumer applications will not be available, and unlimited reconnection waiting for service providers recovery
Flexibility
Registration Center for the peer cluster can be dynamically increased machine deployment instance, all clients will automatically discover the new registry service provider stateless, can increase the dynamic deployment of machine instances, push the new registry service provider information to consumers