org.apache.servicecomb.registry.discovery

Class DiscoveryTree

java.lang.Object

org.apache.servicecomb.registry.discovery.DiscoveryTree

public class DiscoveryTree
extends Object

help to understand DiscoveryTree

 DiscoveryTree is used to:
 1.get all instances by app/microserviceName/versionRule
 2.filter all instances set, and output another set, the output set is instance or something else, this depend on filter set

 DiscoveryFilter have different types:
 1.normal filter: just filter input set
 2.grouping filter: will split input set to groups
 3.convert filter: eg: convert from instance to endpoint
 different types can composite in one filter

 features:
 1.every group combination(eg:1.0.0-2.0.0/1.0.0+/self/RESTful) relate to a loadBalancer instance
 2.if some filter output set is empty, DiscoveryTree can support try refilter logic
   eg: if there is no available instances in self AZ, can refilter in other AZ
   red arrows in help to understand DiscoveryTree, show the refilter logic
 3.every filter must try to cache result, avoid calculate every time.

 usage:
 1.declare a field: DiscoveryTree discoveryTree = new DiscoveryTree();
 2.initialize:
     discoveryTree.loadFromSPI(DiscoveryFilter.class);
     // add filters by your requirement
     discoveryTree.addFilter(new EndpointDiscoveryFilter());
     discoveryTree.sort();
 3.filter for a invocation:
     DiscoveryContext context = new DiscoveryContext();
     context.setInputParameters(invocation);
     VersionedCache endpointsVersionedCache = discoveryTree.discovery(context,
         invocation.getAppId(),
         invocation.getMicroserviceName(),
         invocation.getMicroserviceVersionRule());
     if (endpointsVersionedCache.isEmpty()) {
       // 404 not found logic
       ......
       return;
     }

     // result is endpoints or something else, which is depends on your filter set
     List<Endpoint> endpoints = endpointsVersionedCache.data();

Constructor Summary

Constructors

Constructor and Description
DiscoveryTree()

Method Summary

Modifier and Type	Method and Description
void	addFilter(DiscoveryFilter filter)
DiscoveryTreeNode	discovery(DiscoveryContext context, String appId, String microserviceName, String versionRule)
DiscoveryTreeNode	discovery(DiscoveryContext context, org.apache.servicecomb.foundation.common.cache.VersionedCache inputCache)
protected DiscoveryTreeNode	doDiscovery(DiscoveryContext context, DiscoveryTreeNode parent)
protected DiscoveryTreeNode	getOrCreateRoot(org.apache.servicecomb.foundation.common.cache.VersionedCache inputCache)
protected boolean	isExpired(org.apache.servicecomb.foundation.common.cache.VersionedCache existing, org.apache.servicecomb.foundation.common.cache.VersionedCache inputCache)
protected boolean	isMatch(org.apache.servicecomb.foundation.common.cache.VersionedCache existing, org.apache.servicecomb.foundation.common.cache.VersionedCache inputCache)
void	loadFromSPI(Class<? extends DiscoveryFilter> cls)
void	sort()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DiscoveryTree

public DiscoveryTree()

Method Detail

loadFromSPI

public void loadFromSPI(Class<? extends DiscoveryFilter> cls)

addFilter

public void addFilter(DiscoveryFilter filter)

sort

public void sort()

isMatch

protected boolean isMatch(org.apache.servicecomb.foundation.common.cache.VersionedCache existing,
                          org.apache.servicecomb.foundation.common.cache.VersionedCache inputCache)

isExpired

protected boolean isExpired(org.apache.servicecomb.foundation.common.cache.VersionedCache existing,
                            org.apache.servicecomb.foundation.common.cache.VersionedCache inputCache)

discovery

public DiscoveryTreeNode discovery(DiscoveryContext context,
                                   String appId,
                                   String microserviceName,
                                   String versionRule)

discovery

public DiscoveryTreeNode discovery(DiscoveryContext context,
                                   org.apache.servicecomb.foundation.common.cache.VersionedCache inputCache)

getOrCreateRoot

protected DiscoveryTreeNode getOrCreateRoot(org.apache.servicecomb.foundation.common.cache.VersionedCache inputCache)

doDiscovery

protected DiscoveryTreeNode doDiscovery(DiscoveryContext context,
                                        DiscoveryTreeNode parent)