Examples with LbPolicy io.grpc.grpclb.GrpclbConstants.LbPolicy used on opensource projects

Example 1 with LbPolicy

use of io.grpc.grpclb.GrpclbConstants.LbPolicy in project grpc-java by grpc.

the class GrpclbLoadBalancer method handleResolvedAddresses.

@Override
public void handleResolvedAddresses(List<ResolvedServerInfoGroup> updatedServers, Attributes attributes) {
    LbPolicy newLbPolicy = attributes.get(GrpclbConstants.ATTR_LB_POLICY);
    // LB addresses and backend addresses are treated separately
    List<LbAddressGroup> newLbAddressGroups = new ArrayList<LbAddressGroup>();
    List<ResolvedServerInfoGroup> newBackendServerInfoGroups = new ArrayList<ResolvedServerInfoGroup>();
    for (ResolvedServerInfoGroup serverInfoGroup : updatedServers) {
        String lbAddrAuthority = serverInfoGroup.getAttributes().get(GrpclbConstants.ATTR_LB_ADDR_AUTHORITY);
        EquivalentAddressGroup eag = serverInfoGroup.toEquivalentAddressGroup();
        if (lbAddrAuthority != null) {
            newLbAddressGroups.add(new LbAddressGroup(eag, lbAddrAuthority));
        } else {
            newBackendServerInfoGroups.add(serverInfoGroup);
        }
    }
    if (newBackendServerInfoGroups.isEmpty()) {
        // handleResolvedAddresses()'s javadoc has guaranteed updatedServers is never empty.
        checkState(!newLbAddressGroups.isEmpty(), "No backend address nor LB address.  updatedServers=%s", updatedServers);
        if (newLbPolicy != LbPolicy.GRPCLB) {
            newLbPolicy = LbPolicy.GRPCLB;
            logger.log(Level.FINE, "[{0}] Switching to GRPCLB because all addresses are balancers", logId);
        }
    }
    if (newLbPolicy == null) {
        logger.log(Level.FINE, "[{0}] New config missing policy. Using PICK_FIRST", logId);
        newLbPolicy = LbPolicy.PICK_FIRST;
    }
    // Switch LB policy if requested
    if (newLbPolicy != lbPolicy) {
        shutdownDelegate();
        shutdownLbComm();
        lbAddressGroups = null;
        currentLbIndex = 0;
        switch(newLbPolicy) {
            case PICK_FIRST:
                delegate = checkNotNull(pickFirstBalancerFactory.newLoadBalancer(helper), "pickFirstBalancerFactory.newLoadBalancer()");
                break;
            case ROUND_ROBIN:
                delegate = checkNotNull(roundRobinBalancerFactory.newLoadBalancer(helper), "roundRobinBalancerFactory.newLoadBalancer()");
                break;
            default:
        }
    }
    lbPolicy = newLbPolicy;
    // Consume the new addresses
    switch(lbPolicy) {
        case PICK_FIRST:
        case ROUND_ROBIN:
            checkNotNull(delegate, "delegate should not be null. newLbPolicy=" + newLbPolicy);
            delegate.handleResolvedAddresses(newBackendServerInfoGroups, attributes);
            break;
        case GRPCLB:
            if (newLbAddressGroups.isEmpty()) {
                shutdownLbComm();
                lbAddressGroups = null;
                handleGrpclbError(Status.UNAVAILABLE.withDescription("NameResolver returned no LB address while asking for GRPCLB"));
            } else {
                // See if the currently used LB server is in the new list.
                int newIndexOfCurrentLb = -1;
                if (lbAddressGroups != null) {
                    LbAddressGroup currentLb = lbAddressGroups.get(currentLbIndex);
                    newIndexOfCurrentLb = newLbAddressGroups.indexOf(currentLb);
                }
                lbAddressGroups = newLbAddressGroups;
                if (newIndexOfCurrentLb == -1) {
                    shutdownLbComm();
                    currentLbIndex = 0;
                    startLbComm();
                } else {
                    // Current LB is still in the list, calibrate index.
                    currentLbIndex = newIndexOfCurrentLb;
                }
            }
            break;
        default:
    }
}