Many of Dubbo’s traffic management capabilities are implemented based on Router. In a production environment, if traffic results do not meet expectations, you can use the routing status command to check the routing status to locate possible problems.
When Dubbo receives the address change, it will push the address information to all Routers, and these Routers can calculate the routing packets in advance at this stage and cache them to avoid the need to traverse all provider calculations when calling grouping parameters.
The StateRouter introduced in Dubbo 3 provides the ability to obtain the status of each route in real time through the qos command tool.
The operation and maintenance personnel can obtain the status of the route through the getRouterSnapshot command. For specific commands, please refer to the getRouterSnapshot command document.
**Note: This feature only supports StateRoute, and StateRouter needs to implement the doBuildSnapshot interface based on AbstractStateRouter. **
By default in Dubbo 3, the node status of route calculation is printed when the route filter is empty. Operation and maintenance personnel can judge whether the calculation result of each route meets expectations through logs.
No provider available after route for the service service from registry registration center address on the consumer consumer IP using the dubbo version 3.0.7. Router snapshot is below:
[ Parent (Input: Number of input addresses of the current node) (Current Node Output: Number of calculation results of the current node) (Chain Node Output: Number of intersection results of the current node and subsequent nodes) ] Input: Examples of input addresses (up to 5 are displayed) -> Chain Node Output: Example of addresses output by the current node (up to 5 are displayed)
[Route name (Input: number of input addresses of the current node) (Current Node Output: number of calculation results of the current node) (Chain Node Output: number of intersection results of the current node and subsequent nodes) Router message: routing log] Current Node Output: current node Example of addresses output (up to 5 displayed)
[routing name (Input: current node input address number) (Current Node Output: current node calculation result number) (Chain Node Output: current node and subsequent node intersection result number) Router message: routing log] Current Node Output: current input Examples of addresses for (show up to 5)
needToPrintMessage parameter, and write the messageHolder routing log when needed[19/07/22 07:42:46:046 CST] main WARN cluster.RouterChain: [DUBBO] No provider available after route for the service org.apache.dubbo.samples.governance.api.DemoService from registry 30.227.64.173 on the consumer 30.227.64.173 using the dubbo version 3.0.7. Router snapshot is below:
[ Parent (Input: 2) (Current Node Output: 2) (Chain Node Output: 0) ] Input: 30.227.64.173:20881,30.227.64.173:20880 -> Chain Node Output: Empty
[ MockInvokersSelector (Input: 2) (Current Node Output: 2) (Chain Node Output: 0) Router message: invocation.need.mock not set. Return normal Invokers. ] Current Node Output: 30.227.64.173:20881,30.223.64.17 :20880
[ StandardMeshRuleRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 0) Router message: MeshRuleCache has not been built. Skip route. ] Current Node Output: 30.227.64.173:20881,30.227.624.1803:
[ TagStateRouter (Input: 2) (Current Node Output: 0) (Chain Node Output: 0) Router message: FAILOVER: return all Providers without any tags ] Current Node Output: Empty, dubbo version: 3.0.7, current host: 30.227 .64.173
In some special cases, the request may be called to the wrong server, but because the address selection is not empty, the process information of the route cannot be seen. At this time, you can [Enable full route sampling through qos](../../. ./reference-manual/qos/router-snapshot/). The latest routing snapshot can be obtained remotely through the getRecentRouterSnapshot command of qos.
dubbo>getRecentRouterSnapshot
1658224330156 - Router snapshot service com.dubbo.dubbointegration.BackendService from registry 172.18.111.184 on the consumer 172.18.111.184 using the dubbo version 3.0.9 is below:
[ Parent (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) ] Input: 172.18.111.187:20880,172.18.111.183:20880 -> Chain Node Output: 172.18.111.187:20880.3172.18 :20880
[ MockInvokersSelector (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: invocation.need.mock not set. Return normal Invokers. ] Current Node Output: 172.18.111.187:20880,172.183.111. :20880
[ StandardMeshRuleRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: MeshRuleCache has not been built. Skip route. ] Current Node Output: 172.18.111.187:20880,172.1803:1121.88
[ TagStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Disable Tag Router. Reason: tagRouterRule is invalid or disabled ] Current Node Output: 172.18.111.187:20880,172.183.111. 20880
[ ServiceStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Directly return. Reason: Invokers from previous router is empty or conditionRouters is empty. ] Current Node Output: 172.18.111.187:20880 ,172.18.111.183:20880
[ AppStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Directly return. Reason: Invokers from previous router is empty or conditionRouters is empty. ] Current Node Output: 172.18.111.187:20880 ,172.18.111.183:20880
1658224330156 - Router snapshot service com.dubbo.dubbointegration.BackendService from registry 172.18.111.184 on the consumer 172.18.111.184 using the dubbo version 3.0.9 is below:
[ Parent (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) ] Input: 172.18.111.187:20880,172.18.111.183:20880 -> Chain Node Output: 172.18.111.187:20880.3172.18 :20880
[ MockInvokersSelector (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: invocation.need.mock not set. Return normal Invokers. ] Current Node Output: 172.18.111.187:20880,172.183.111. :20880
[ StandardMeshRuleRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: MeshRuleCache has not been built. Skip route. ] Current Node Output: 172.18.111.187:20880,172.1803:1121.88
[ TagStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Disable Tag Router. Reason: tagRouterRule is invalid or disabled ] Current Node Output: 172.18.111.187:20880,172.183.111. 20880
[ ServiceStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Directly return. Reason: Invokers from previous router is empty or conditionRouters is empty. ] Current Node Output: 172.18.111.187:20880 ,172.18.111.183:20880
[ AppStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Directly return. Reason: Invokers from previous router is empty or conditionRouters is empty. ] Current Node Output: 172.18.111.187:20880 ,172.18.111.183:20880
···
dubbo>
If the log is empty due to the mismatch of the log framework, you can refer to Log Framework Adaptation and Runtime Management to dynamically modify the log output framework.