Share Limiter Tweaks

src/server/poolserver/Main.cpp

@@ -49,7 +49,7 @@ bool InitConfig(int argc, char *argv[])
         ("StratumBlockCheckTime", boost::program_options::value<uint32>()->default_value(2000), "Time between block checks in ms")
         ("RetargetInterval", boost::program_options::value<uint32>()->default_value(20), "Time between difficulty checks in seconds")
         ("RetargetTimeBuffer", boost::program_options::value<uint32>()->default_value(60*5), "Buffer of shares to keep (in seconds)")
-        ("RetargetSharesPerMin", boost::program_options::value<uint32>()->default_value(15), "How many shares per min to target for")
+        ("RetargetTimePerShare", boost::program_options::value<double>()->default_value(10), "Target in seconds between shares")
         ("RetargetVariance", boost::program_options::value<uint32>()->default_value(40), "Maximum allowed variance in percent before difficulty change")
         ("RetargetMinDiff", boost::program_options::value<uint32>()->default_value(1), "Minimum difficulty (also starting difficulty)")
         ("RetargetMaxDiff", boost::program_options::value<uint32>()->default_value(1000000), "Maximum difficulty we can reach")

src/server/poolserver/Stratum/Client.cpp

@@ -79,18 +79,6 @@ namespace Stratum
     {
         JSON params = msg["params"];
         
-        // Share limiter
-        if (!_shareLimiter.Submit()) {
-            JSON response;
-            response["id"] = msg["id"];
-            response["result"];
-            response["error"].Add(int64(20));
-            response["error"].Add("Blocked by share limiter");
-            response["error"].Add(JSON());
-            SendMessage(response);
-            return;
-        }
-        
         // check username
         std::string username = params[0].GetString();
         if (!_workers.count(username)) {
@@ -124,6 +112,21 @@ namespace Stratum
             return;
         }
         
+        // Get job
+        Job& job = _jobs[jobid];
+        
+        // Share limiter
+        if (!_shareLimiter.Submit(job.diff)) {
+            JSON response;
+            response["id"] = msg["id"];
+            response["result"];
+            response["error"].Add(int64(20));
+            response["error"].Add("Blocked by share limiter");
+            response["error"].Add(JSON());
+            SendMessage(response);
+            return;
+        }
+        
         BinaryData extranonce2 = Util::ASCIIToBin(params[2].GetString());
         if (extranonce2.size() != 4) {
             sLog.Error(LOG_STRATUM, "Wrong extranonce size");
@@ -162,9 +165,6 @@ namespace Stratum
             SendMessage(response);
             return;
         }
-    
-        // Get job
-        Job& job = _jobs[jobid];
         
         ByteBuffer share;
         share << extranonce2 << timebuf << noncebuf;

src/server/poolserver/Stratum/Client.h

@@ -143,7 +143,6 @@ namespace Stratum
                 _socket,
                 boost::asio::buffer(redirect.c_str(), redirect.length()),
                 _ioStrand.wrap(boost::bind(&Client::_OnSend, shared_from_this(), boost::asio::placeholders::error)));
-            Disconnect();
         }
         
         void CloseSocket()

src/server/poolserver/Stratum/ShareLimiter.cpp

@@ -7,14 +7,14 @@
 namespace Stratum
 {
     // Returning false will stop any further share verifications (DoS prevention, etc)
-    bool ShareLimiter::Submit()
+    bool ShareLimiter::Submit(uint64 diff)
     {
         ++_totalShares;
         
         uint64 curTime = Util::Date();
         uint64 sinceLast = curTime - _lastRetarget;
         
-        _shares.push_back(curTime);
+        _shares.push_back(ShareLimiterRecord(diff, curTime));
         
         if (sinceLast < sConfig.Get<uint32>("RetargetInterval"))
             return true;
@@ -27,34 +27,40 @@ namespace Stratum
             return false;
         }
         
+        // Drop old shares
         while (_shares.size()) {
-            if (_shares.front() > curTime - sConfig.Get<uint32>("RetargetTimeBuffer"))
+            if (_shares.front().time > curTime - sConfig.Get<uint32>("RetargetTimeBuffer"))
                 break;
             _shares.pop_front();
         }
         
-        uint32 interval = sConfig.Get<uint32>("RetargetTimeBuffer");
+        double totalWeighted = 0;
+        for (uint32 i = 0; i < _shares.size(); ++i)
+            totalWeighted += _shares[i].diff;
         
-        // Calculate shares/min
-        double speed = double(_shares.size()*60) / double(interval);
+        double interval = std::min(curTime - _startTime, uint64(sConfig.Get<uint32>("RetargetTimeBuffer")));
         
-        // Calculate difference from pool target in %
-        double variance = speed / double(sConfig.Get<uint32>("RetargetSharesPerMin"));
+        // Calculate hashrate in MH/s
+        double hashrate = (MEGAHASHCONST*totalWeighted)/interval;
         
-        sLog.Debug(LOG_STRATUM, "Miner variance: %f speed: %f", variance, speed);
-        
-        // Check if we need to retarget
-        if (variance*100 < sConfig.Get<uint32>("RetargetVariance"))
-            return true;
-        
-        uint64 newDiff = double(_client->GetDifficulty()) * variance;
+        // Calculate new diff
+        uint64 newDiff = (hashrate * sConfig.Get<double>("RetargetTimePerShare")) / MEGAHASHCONST;
         
+        // Check Limits
         if (newDiff < sConfig.Get<uint32>("RetargetMinDiff"))
             newDiff = sConfig.Get<uint32>("RetargetMinDiff");
-        
         if (newDiff > sConfig.Get<uint32>("RetargetMaxDiff"))
             newDiff = sConfig.Get<uint32>("RetargetMaxDiff");
         
+        // Calculate variance in %
+        uint32 variance = abs(((newDiff - _client->GetDifficulty()) * 100) / _client->GetDifficulty());
+        
+        sLog.Debug(LOG_STRATUM, "Miner new diff: %u Variance: %u%% Hashrate: %f MH/s", newDiff, variance, hashrate);
+        
+        // Check if we need to retarget
+        if (variance < sConfig.Get<uint32>("RetargetVariance"))
+            return true;
+        
         _client->SetDifficulty(newDiff, true);
         
         return true;

src/server/poolserver/Stratum/ShareLimiter.h

@@ -6,20 +6,31 @@
 
 #include <deque>
 
+// 2^32 * 10^-6
+#define MEGAHASHCONST 4294.967296
+
 namespace Stratum
 {
     class Client;
     
+    struct ShareLimiterRecord
+    {
+        ShareLimiterRecord(uint64 adiff, uint64 atime) : diff(adiff), time(atime) {}
+        uint64 diff;
+        uint64 time;
+    };
+    
     class ShareLimiter
     {
     public:
         ShareLimiter(Client* client) : _client(client), _totalShares(0), _totalBadShares(0)
         {
-            _startTime = Util::Date();
+            // Minus one to prevent crash when interval is zero
+            _startTime = Util::Date()-1;
             _lastRetarget = _startTime;
         }
         
-        bool Submit();
+        bool Submit(uint64 diff);
         
         void LogBad()
         {
@@ -27,7 +38,7 @@ namespace Stratum
         }
         
     private:
-        std::deque<uint64> _shares;
+        std::deque<ShareLimiterRecord> _shares;
         Client* _client;
         uint64 _lastRetarget;
         uint64 _startTime;