added automatic limitation of turtle search and turtle tunnel requests as a function of current traffic

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@4222 b45a01b8-16f6-495d-af2f-9b41ad6348cc
This commit is contained in:
csoler 2011-05-28 14:39:47 +00:00
parent 4d846513e2
commit f3ca5b9941

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@ -84,7 +84,8 @@ static const time_t MAXIMUM_TUNNEL_IDLE_TIME = 60 ; /// maximum life time of
static const time_t EMPTY_TUNNELS_DIGGING_TIME = 50 ; /// look into tunnels regularly every 50 sec.
static const time_t TUNNEL_SPEED_ESTIMATE_LAPSE = 5 ; /// estimate tunnel speed every 5 seconds
static const time_t TUNNEL_CLEANING_LAPS_TIME = 10 ; /// clean tunnels every 10 secs
static const uint32_t MAX_TUNNEL_REQS_PER_SECOND= 1 ; /// maximum number of tunnel requests per second. Was 0.5 before
static const uint32_t MAX_TUNNEL_REQS_PER_SECOND= 1 ; /// maximum number of tunnel requests issued per second. Was 0.5 before
static const uint32_t MAX_ALLOWED_SR_IN_CACHE = 120 ; /// maximum number of search requests allowed in cache. That makes 2 per sec.
p3turtle::p3turtle(p3ConnectMgr *cm,ftServer *fs)
:p3Service(RS_SERVICE_TYPE_TURTLE), p3Config(CONFIG_TYPE_TURTLE), mConnMgr(cm)
@ -145,9 +146,10 @@ int p3turtle::tick()
RsStackMutex stack(mTurtleMtx); /********** STACK LOCKED MTX ******/
_last_tunnel_management_time = now ;
// update traffic statistics
_traffic_info = _traffic_info*0.75 + _traffic_info_buffer*0.25 ;
// Update traffic statistics. The constants are important: they allow a smooth variation of the
// traffic speed, which is used to moderate tunnel requests statistics.
//
_traffic_info = _traffic_info*0.9 + _traffic_info_buffer*0.1 ;
_traffic_info_buffer.reset() ;
}
}
@ -549,7 +551,7 @@ RsSerialiser *p3turtle::setupSerialiser()
return rss ;
}
bool p3turtle::saveList(bool& cleanup, std::list<RsItem*>& lst)
bool p3turtle::saveList(bool& cleanup, std::list<RsItem*>&)
{
#ifdef P3TURTLE_DEBUG
std::cerr << "p3turtle: saving list..." << std::endl ;
@ -700,6 +702,15 @@ void p3turtle::handleSearchRequest(RsTurtleSearchRequestItem *item)
std::cerr << "Received search request from peer " << item->PeerId() << ": " << std::endl ;
item->print(std::cerr,0) ;
#endif
if(_search_requests_origins.size() > MAX_ALLOWED_SR_IN_CACHE)
{
#ifdef P3TURTLE_DEBUG
std::cerr << " Dropping, because the search request cache is full." << std::endl ;
#endif
std::cerr << " More than " << MAX_ALLOWED_SR_IN_CACHE << " search request in cache. A peer is probably trying to flood your network See the depth charts to find him." << std::endl;
return ;
}
// If the item contains an already handled search request, give up. This
// happens when the same search request gets relayed by different peers
//
@ -1625,8 +1636,6 @@ void p3turtle::handleTunnelRequest(RsTurtleOpenTunnelItem *item)
res_item->tunnel_id = item->partial_tunnel_id ^ generatePersonalFilePrint(item->file_hash,false) ;
res_item->PeerId(item->PeerId()) ;
_traffic_info_buffer.tr_up_Bps += static_cast<RsTurtleItem*>(res_item)->serial_size() ;
sendItem(res_item) ;
// Note in the tunnels list that we have an ending tunnel here.
@ -1659,7 +1668,7 @@ void p3turtle::handleTunnelRequest(RsTurtleOpenTunnelItem *item)
// If search depth not too large, also forward this search request to all other peers.
//
bool random_bypass = (item->depth == TURTLE_MAX_SEARCH_DEPTH && (((_random_bias ^ item->partial_tunnel_id)&0x7)==2)) ;
bool random_bypass = (item->depth >= TURTLE_MAX_SEARCH_DEPTH && (((_random_bias ^ item->partial_tunnel_id)&0x7)==2)) ;
if(item->depth < TURTLE_MAX_SEARCH_DEPTH || random_bypass)
{
@ -1669,11 +1678,37 @@ void p3turtle::handleTunnelRequest(RsTurtleOpenTunnelItem *item)
std::cerr << " Forwarding tunnel request: Looking for online peers" << std::endl ;
#endif
// TR forwarding. We must pay attention not to flood the network. The policy is to force a statistical behavior
// according to the followin grules:
// - below a number of tunnel request forwards per second MAX_TR_FORWARD_PER_SEC, we keep the traffic
// - if we get close to that limit, we drop long tunnels first with a probability that is larger for long tunnels
//
// Variables involved:
// distance_to_maximum : in [0,inf] is the proportion of the current up TR speed with respect to the maximum allowed speed. This is estimated
// as an average between the average number of TR over the 60 last seconds and the current TR up speed.
// corrected_distance : in [0,inf] is a squeezed version of distance: small values become very small and large values become very large.
// depth_peer_probability : basic probability of forwarding when the speed limit is reached.
// forward_probability : final probability of forwarding the packet, per peer.
//
// When the number of peers increases, the speed limit is reached faster, but the behavior per peer is the same.
//
static const float depth_peer_probability[7] = { 1.0f,0.99f,0.9f,0.7f,0.4f,0.15f,0.1f } ;
static const int TUNNEL_REQUEST_PACKET_SIZE = 50 ;
static const int MAX_TR_FORWARD_PER_SEC = 40 ;
static const int DISTANCE_SQUEEZING_POWER = 8 ;
float distance_to_maximum = std::min(100.0f,_traffic_info.tr_up_Bps/(float)(TUNNEL_REQUEST_PACKET_SIZE*MAX_TR_FORWARD_PER_SEC)) ;
float corrected_distance = pow(distance_to_maximum,DISTANCE_SQUEEZING_POWER) ;
float forward_probability = pow(depth_peer_probability[std::min((uint16_t)6,item->depth)],corrected_distance) ;
#ifdef P3TURTLE_DEBUG
std::cerr << "Forwarding probability: depth=" << item->depth << ", distance to max speed=" << distance_to_maximum << ", corrected=" << corrected_distance << ", prob.=" << forward_probability << std::endl;
#endif
for(std::list<std::string>::const_iterator it(onlineIds.begin());it!=onlineIds.end();++it)
if(*it != item->PeerId())
if(*it != item->PeerId() && RSRandom::random_f32() <= forward_probability)
{
#ifdef P3TURTLE_DEBUG
std::cerr << " Forwarding request to peer = " << *it << std::endl ;
std::cerr << " Forwarding request to peer = " << *it << std::endl ;
#endif
// Copy current item and modify it.
RsTurtleOpenTunnelItem *fwd_item = new RsTurtleOpenTunnelItem(*item) ;