Interface LoadReportingServiceGrpc.AsyncService

All Known Implementing Classes:

LoadReportingServiceGrpc.LoadReportingServiceImplBase

Enclosing class:

LoadReportingServiceGrpc

public static interface LoadReportingServiceGrpc.AsyncService

Method Summary

Modifier and Type	Method	Description
default io.grpc.stub.StreamObserver<LoadStatsRequest>	streamLoadStats(io.grpc.stub.StreamObserver<LoadStatsResponse> responseObserver)	Advanced API to allow for multi-dimensional load balancing by remote server.

Method Details

streamLoadStats

default io.grpc.stub.StreamObserver<LoadStatsRequest> streamLoadStats(io.grpc.stub.StreamObserver<LoadStatsResponse> responseObserver)

Advanced API to allow for multi-dimensional load balancing by remote
server. For receiving LB assignments, the steps are:
1, The management server is configured with per cluster/zone/load metric
   capacity configuration. The capacity configuration definition is
   outside of the scope of this document.
2. Envoy issues a standard {Stream,Fetch}Endpoints request for the clusters
   to balance.
Independently, Envoy will initiate a StreamLoadStats bidi stream with a
management server:
1. Once a connection establishes, the management server publishes a
   LoadStatsResponse for all clusters it is interested in learning load
   stats about.
2. For each cluster, Envoy load balances incoming traffic to upstream hosts
   based on per-zone weights and/or per-instance weights (if specified)
   based on intra-zone LbPolicy. This information comes from the above
   {Stream,Fetch}Endpoints.
3. When upstream hosts reply, they optionally add header <define header
   name> with ASCII representation of EndpointLoadMetricStats.
4. Envoy aggregates load reports over the period of time given to it in
   LoadStatsResponse.load_reporting_interval. This includes aggregation
   stats Envoy maintains by itself (total_requests, rpc_errors etc.) as
   well as load metrics from upstream hosts.
5. When the timer of load_reporting_interval expires, Envoy sends new
   LoadStatsRequest filled with load reports for each cluster.
6. The management server uses the load reports from all reported Envoys
   from around the world, computes global assignment and prepares traffic
   assignment destined for each zone Envoys are located in. Goto 2.