/**
* Process the Query, and generate response
*
* @param query the query to process
*/
public int processQuery(ResolverQueryMsg query) {
if (!useRouteResolver) { // Route resolver disabled
return ResolverService.OK;
}
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("processQuery starts");
}
RouteQuery routeQuery = null;
Reader ip = null;
try {
ip = new StringReader(query.getQuery());
StructuredTextDocument asDoc =
(StructuredTextDocument)
StructuredDocumentFactory.newStructuredDocument(MimeMediaType.XMLUTF8, ip);
routeQuery = new RouteQuery(asDoc);
} catch (Throwable e) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("Malformed Route query ", e);
}
return ResolverService.OK;
} finally {
try {
if (null != ip) {
ip.close();
ip = null;
}
} catch (Throwable ignored) {;
}
}
PeerID pId = routeQuery.getDestPeerID();
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("processQuery: looking for route to " + pId);
}
RouteAdvertisement srcRoute = routeQuery.getSrcRoute();
List badHops = routeQuery.getBadHops();
if (LOG.isEnabledFor(Level.DEBUG)) {
if (badHops != null) {
LOG.debug("processQuery: bad Hops");
for (int i = 0; i < badHops.size(); i++) {
LOG.debug("processQuery: :" + ((PeerID) badHops.get(i)).toString());
}
}
}
// if our source route is not null, then publish it
if (srcRoute != null) {
if (!(srcRoute.getDestPeerID()).equals(localPeerId)) {
// This is not our own peer adv so we must not keep it
// longer than its expiration time.
try {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("processQuery: publishing sender route info " + srcRoute.getDestPeerID());
}
// we only need to publish this route if
// we don't know about it yet
// XXX: here is where we could be more conservative and use isNormallyReachable() instead,
// thus excluding
// incoming messengers.
if ((!router.isLocalRoute(router.pid2addr(srcRoute.getDestPeerID())))
&& (!router.isRoutedRoute(router.pid2addr(srcRoute.getDestPeerID())))) {
routeCM.publishRoute(srcRoute);
}
} catch (Exception e) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("Could not publish Route Adv from query - discard", e);
}
return ResolverService.OK;
}
}
} else {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("No src Route in route query - discard ");
}
return ResolverService.OK;
}
if (pId == null) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("Malformed route query request, no PeerId - discard");
}
return ResolverService.OK;
}
// We have more luck with that one because, since it is part of OUR
// message, and not part of the resolver protocol, it is in OUR
// format.
EndpointAddress qReqAddr = router.pid2addr(pId);
RouteAdvertisement route = null;
// check if this peer has a route to the destination
// requested
boolean found = false;
if (qReqAddr.equals(localPeerAddr)) {
found = true;
// return the route that is my local route
route = router.getMyLocalRoute();
} else {
// only rendezvous can respond to route requests
// if not we are generating too much traffic
// XXX: here is where we could be more conservative and use isNormallyReachable() instead,
// thus excluding
// incoming messengers.
if (router.isLocalRoute(qReqAddr)) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("processQuery: peer has direct route to destination ");
}
// we should set the route to something :-)
found = true;
// this peer has a direct route to the destination
// return the short route advertisement we know for this peer
// (For us it is zero hop, and we advertise ourself as the routing
// peer in the response. The stiching is done by whoever gets that
// response). May be there are more than one hop advertised in-there...
// alternate routing peers...should we leave them ?
// For now, we keep the full dest, but wack the hops.
route =
(RouteAdvertisement)
AdvertisementFactory.newAdvertisement(RouteAdvertisement.getAdvertisementType());
AccessPointAdvertisement ap =
(AccessPointAdvertisement)
AdvertisementFactory.newAdvertisement(
AccessPointAdvertisement.getAdvertisementType());
ap.setPeerID(pId);
route.setDest(ap);
} else {
route = router.getRoute(qReqAddr, false);
if (route != null) {
found = true;
// check if we were given some bad hops info
// and see if the found route contains
// any of these bad hops. In that case, we need
// to mark this route as bad
for (int i = 0; i < badHops.size(); i++) {
// destination is known to be bad
if (router.addr2pid(qReqAddr).equals(((PeerID) badHops.get(i)))) {
processBadRoute((PeerID) badHops.get(i), route);
found = false;
break;
}
if (route.containsHop((PeerID) badHops.get(i))) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug(
"processQuery: peer has bad route due to "
+ ((PeerID) badHops.get(i)).toString());
}
processBadRoute((PeerID) badHops.get(i), route);
found = false;
break;
}
}
}
}
}
if (!found) {
// discard the request if we are not a rendezvous
// else forward to the next peers
if (!group.isRendezvous()) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("discard query forwarding as not a rendezvous");
}
return ResolverService.OK;
}
// did not find a route, check our srdi cache
// make sure we protect against out of sync
// SRDI index
// srdi forwarding is only involved once the Index entry has
// been found and we forwarded the resolver query. Afterward a
// normal walk proceeds from the initial SRDI index pointing
// rdv. This is done to protect against potential loopback
// entries in the SRDI cache index due to out of sync peerview
// and index.
if (query.getHopCount() < 2) {
// check local SRDI cache to see if we have the entry
// we look for 10 entries, will pickup one randomly
Vector results = srdiIndex.query("route", "DstPID", pId.toString(), 10);
if (results.size() > 0) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("processQuery srdiIndex lookup match :" + results.size());
}
// remove any non-rdv peers to avoid sending
// to a non-rdv peers and garbage collect the SRDI
// index in the process
Vector clean = cleanupAnyEdges(query.getSrc(), results);
if (clean.size() > 0) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("found an srdi entry forwarding query to SRDI peer");
}
// The purpose of incrementing the hopcount
// when an SRDI index match is found (we got a
// pointer to a rdv that should have the route) is to
// restrict any further forwarding. The increment
// count is only done when a matching SRDI index is
// found. Not when the replica is selected as we
// still need to forward the query. This restriction
// is purposelly done to avoid too many longjumps
// within a walk.
query.incrementHopCount();
// Note: this forwards the query to 1 peer randomly
// selected from the result
srdi.forwardQuery(clean, query, 1);
// tell the resolver no further action is needed.
return ResolverService.OK;
}
}
}
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("did not find a route or SRDI index");
}
// force a walk
return ResolverService.Repropagate;
}
// we found a route send the response
try {
if (route == null) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("we should have had a route at this point");
}
return ResolverService.OK;
}
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("processQuery: we have a route build route response" + route.display());
}
RouteAdvertisement myRoute = router.getMyLocalRoute();
// make sure we initialized our local
// route info as we will need it to respond. We may
// not have our route if we are still
// waiting for a relay connection.
if (myRoute == null) {
return ResolverService.OK;
}
RouteResponse routeResponse = new RouteResponse();
routeResponse.setDestRoute(route);
routeResponse.setSrcRoute(myRoute);
if (routeResponse == null) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("error creating route response");
}
return ResolverService.OK;
}
// construct a response from the query
ResolverResponseMsg res = query.makeResponse();
res.setCredential(credentialDoc);
res.setResponse(routeResponse.toString());
resolver.sendResponse(query.getSrc(), res);
return ResolverService.OK;
} catch (Exception ee) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("processQuery: error while processing query ", ee);
}
return ResolverService.OK;
}
}
/**
* bad route, so let's remove everything we have so we can start from scratch. We are maintaining
* a bad route up to DEFAULT_ROUTE experition after that we consider it to be ok to retry the same
* route We are removing both the route and peer advertisement to force a new route query
*
* @param src peer that reply with the NACK route info
* @param dest original route information
*/
private void processBadRoute(PeerID badHop, RouteAdvertisement dest) {
EndpointAddress addr = router.pid2addr(dest.getDestPeerID());
if (addr == null) {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("remove bad route has a bad route info - discard");
}
return;
}
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("remove bad route info for dest " + dest.display());
if (badHop != null) {
LOG.debug("remove bad route bad hop " + badHop);
}
}
try {
// check first that we still have the same route, we may already
// using a new route
RouteAdvertisement currentRoute = router.getRoute(addr, false);
if (currentRoute == null) { // we already cleanup the route info
return;
}
// check if we still have the old bad route, we may have
// already updated the route
if (!currentRoute.equals(dest)) {
// check if the bad hop is not the destination
// if it is then we still have a bad route
if (!(badHop.equals(router.addr2pid(addr)))) {
// check if the new route may still contain the bad hop
// the known bad hop is the hop after the src peer that
// responded with a NACK route
// In this case we also consider the route bad
if (badHop != null) { // this should really not be null
if (!currentRoute.containsHop(badHop)) {
return; // we are ok
} else {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("current route is bad because it contains known bad hop" + badHop);
}
}
} else { // we could get the bad hop, so consider the route ok
return;
}
} else {
if (LOG.isEnabledFor(Level.DEBUG)) {
LOG.debug("current route is bad because it contains known bad destination" + badHop);
}
}
}
// keep the bad one in a cache table so we don't retry them
// right away. We use the default route timeout
BadRoute badRoute = ((BadRoute) router.getBadRoute(addr));
if (badRoute != null) {
Long nextTry = badRoute.getExpiration();
if (nextTry.longValue()
> System.currentTimeMillis()) { // nothing to do the information is still valid
} else {
// It is ancient knowlege update it
nextTry = new Long(TimeUtils.toAbsoluteTimeMillis(BADROUTE_EXPIRATION));
badRoute.setExpiration(nextTry);
}
List badHops = badRoute.getHops();
// check if we have to add a new bad hop
// to our bad route
if (badHop != null) {
if (!badHops.contains(badHop)) {
badHops.add(badHop);
// new expiration
nextTry = new Long(TimeUtils.toAbsoluteTimeMillis(BADROUTE_EXPIRATION));
badRoute.setHops(badHops);
badRoute.setExpiration(nextTry);
}
}
router.setBadRoute(addr, badRoute);
return;
} else {
// create a new NACK route entry
Vector badHops = new Vector();
if (badHop != null) {
badHops.add(badHop);
}
badRoute =
new BadRoute(
dest, new Long(TimeUtils.toAbsoluteTimeMillis(BADROUTE_EXPIRATION)), badHops);
router.setBadRoute(addr, badRoute);
}
// remove route from route CM
routeCM.flushRoute(addr);
// let's remove the remote route info from the routing table
// we do this after we removed the entries from the CM
// to avoid that another thread is putting back the entry
router.removeRoute(addr);
} catch (Exception ex) {
if (LOG.isEnabledFor(Level.WARN)) {
LOG.warn("exception during bad route removal", ex);
}
}
}
