Examples with PermutationGenerator com.iplanet.dpro.session.service.PermutationGenerator used on opensource projects

Example 1 with PermutationGenerator

use of com.iplanet.dpro.session.service.PermutationGenerator in project OpenAM by OpenRock.

the class MultiServerClusterMonitor method locateCurrentHostServer.

/**
     * Determines current hosting server instance for internal request routing
     * mode.
     *
     * @param sid session id
     * @return server id for the server instance determined to be the current
     *         host
     * @throws com.iplanet.dpro.session.SessionException
     */
String locateCurrentHostServer(SessionID sid) throws SessionException {
    String primaryID = sid.getExtension().getPrimaryID();
    String serverID = sid.getSessionServerID();
    // if this is our local Server
    if (serverConfig.isLocalServer(serverID)) {
        return serverID;
    }
    // if session is from remote site
    if (!serverConfig.isPrimaryServer(serverID)) {
        return serverID;
    }
    // Ensure we have a Cluster State Service Available.
    synchronized (this) {
        if (clusterStateService == null) {
            try {
                initializeClusterService();
            } catch (Exception e) {
                sessionDebug.error("Unable to Initialize the Cluster Service, please review Configuration settings.", e);
                throw new SessionException(e);
            }
        }
    }
    // Check for Service Available.
    if (clusterStateService.isUp(primaryID)) {
        return primaryID;
    } else {
        int selectionListSize = clusterStateService.getServerSelectionListSize();
        String sKey = sid.getExtension().getStorageKey();
        if (sKey == null) {
            throw new SessionException("SessionService.locateCurrentHostServer: StorageKey is null");
        }
        PermutationGenerator perm = new PermutationGenerator(sKey.hashCode(), selectionListSize);
        String selectedServerId = null;
        for (int i = 0; i < selectionListSize; ++i) {
            selectedServerId = clusterStateService.getServerSelection(perm.itemAt(i));
            if (selectedServerId == null) {
                continue;
            }
            if (clusterStateService.isUp(selectedServerId)) {
                break;
            }
        }
        // selection process is guaranteed to succeed
        return selectedServerId;
    }
}