diff --git a/trunk/src/app/srs_app_conn.cpp b/trunk/src/app/srs_app_conn.cpp
index 707aa4af8..b9b88f87c 100644
--- a/trunk/src/app/srs_app_conn.cpp
+++ b/trunk/src/app/srs_app_conn.cpp
@@ -52,6 +52,9 @@ SrsResourceManager::SrsResourceManager(const std::string& label, bool verbose)
     trd = NULL;
     p_disposing_ = NULL;
     removing_ = false;
+
+    nn_level0_cache_ = 100000;
+    conns_level0_cache_ = new SrsResourceFastIdItem[nn_level0_cache_];
 }
 
 SrsResourceManager::~SrsResourceManager()
@@ -65,6 +68,8 @@ SrsResourceManager::~SrsResourceManager()
     }
 
     clear();
+
+    srs_freepa(conns_level0_cache_);
 }
 
 srs_error_t SrsResourceManager::start()
@@ -114,10 +119,14 @@ srs_error_t SrsResourceManager::cycle()
     return err;
 }
 
-void SrsResourceManager::add(ISrsResource* conn)
+void SrsResourceManager::add(ISrsResource* conn, bool* exists)
 {
     if (std::find(conns_.begin(), conns_.end(), conn) == conns_.end()) {
         conns_.push_back(conn);
+    } else {
+        if (exists) {
+            *exists = false;
+        }
     }
 }
 
@@ -129,8 +138,35 @@ void SrsResourceManager::add_with_id(const std::string& id, ISrsResource* conn)
 
 void SrsResourceManager::add_with_fast_id(uint64_t id, ISrsResource* conn)
 {
-    add(conn);
+    bool exists = false;
+    add(conn, &exists);
     conns_fast_id_[id] = conn;
+
+    if (exists) {
+        return;
+    }
+
+    // For new resource, build the level-0 cache for fast-id.
+    SrsResourceFastIdItem* item = &conns_level0_cache_[(id | id>>32) % nn_level0_cache_];
+
+    // Ignore if exits item.
+    if (item->fast_id && item->fast_id == id) {
+        return;
+    }
+
+    // Fresh one, create the item.
+    if (!item->fast_id) {
+        item->fast_id = id;
+        item->impl = conn;
+        item->nn_collisions = 1;
+        item->available = true;
+    }
+
+    // Collision, increase the collisions.
+    if (item->fast_id != id) {
+        item->nn_collisions++;
+        item->available = false;
+    }
 }
 
 void SrsResourceManager::add_with_name(const std::string& name, ISrsResource* conn)
@@ -152,6 +188,11 @@ ISrsResource* SrsResourceManager::find_by_id(std::string id)
 
 ISrsResource* SrsResourceManager::find_by_fast_id(uint64_t id)
 {
+    SrsResourceFastIdItem* item = &conns_level0_cache_[(id | id>>32) % nn_level0_cache_];
+    if (item->available && item->fast_id == id) {
+        return item->impl;
+    }
+
     map<uint64_t, ISrsResource*>::iterator it = conns_fast_id_.find(id);
     return (it != conns_fast_id_.end())? it->second : NULL;
 }
@@ -332,6 +373,15 @@ void SrsResourceManager::dispose(ISrsResource* c)
         if (c != it->second) {
             ++it;
         } else {
+            // Update the level-0 cache for fast-id.
+            uint64_t id = it->first;
+            SrsResourceFastIdItem* item = &conns_level0_cache_[(id | id>>32) % nn_level0_cache_];
+            item->nn_collisions--;
+            if (!item->nn_collisions) {
+                item->fast_id = 0;
+                item->available = false;
+            }
+
             // Use C++98 style: https://stackoverflow.com/a/4636230
             conns_fast_id_.erase(it++);
         }
diff --git a/trunk/src/app/srs_app_conn.hpp b/trunk/src/app/srs_app_conn.hpp
index 8af94e956..db10ee423 100644
--- a/trunk/src/app/srs_app_conn.hpp
+++ b/trunk/src/app/srs_app_conn.hpp
@@ -52,6 +52,27 @@ public:
     virtual void on_disposing(ISrsResource* c) = 0;
 };
 
+// The item to identify the fast id object.
+class SrsResourceFastIdItem
+{
+public:
+    // If available, use the resource in item.
+    bool available;
+    // How many resource have the same fast-id, which contribute a collision.
+    int nn_collisions;
+    // The first fast-id of resources.
+    uint64_t fast_id;
+    // The first resource object.
+    ISrsResource* impl;
+public:
+    SrsResourceFastIdItem() {
+        available = false;
+        nn_collisions = 0;
+        fast_id = 0;
+        impl = NULL;
+    }
+};
+
 // The resource manager remove resource and delete it asynchronously.
 class SrsResourceManager : virtual public ISrsCoroutineHandler, virtual public ISrsResourceManager
 {
@@ -78,6 +99,9 @@ private:
     std::map<std::string, ISrsResource*> conns_id_;
     // The connections with resource fast(int) id.
     std::map<uint64_t, ISrsResource*> conns_fast_id_;
+    // The level-0 fast cache for fast id.
+    int nn_level0_cache_;
+    SrsResourceFastIdItem* conns_level0_cache_;
     // The connections with resource name.
     std::map<std::string, ISrsResource*> conns_name_;
 public:
@@ -91,7 +115,7 @@ public:
 public:
     virtual srs_error_t cycle();
 public:
-    void add(ISrsResource* conn);
+    void add(ISrsResource* conn, bool* exists = NULL);
     void add_with_id(const std::string& id, ISrsResource* conn);
     void add_with_fast_id(uint64_t id, ISrsResource* conn);
     void add_with_name(const std::string& name, ISrsResource* conn);
diff --git a/trunk/src/utest/srs_utest_app.cpp b/trunk/src/utest/srs_utest_app.cpp
index 010ed4272..a0ad704f7 100644
--- a/trunk/src/utest/srs_utest_app.cpp
+++ b/trunk/src/utest/srs_utest_app.cpp
@@ -30,6 +30,119 @@ using namespace std;
 #include <srs_app_config.hpp>
 
 #include <srs_app_st.hpp>
+#include <srs_service_conn.hpp>
+#include <srs_app_conn.hpp>
+
+class MockIDResource : public ISrsResource
+{
+public:
+    int id;
+    MockIDResource(int v) {
+        id = v;
+    }
+    virtual ~MockIDResource() {
+    }
+    virtual const SrsContextId& get_id() {
+        return _srs_context->get_id();
+    }
+    virtual std::string desc() {
+        return "";
+    }
+};
+
+VOID TEST(AppResourceManagerTest, FindByFastID)
+{
+    srs_error_t err = srs_success;
+
+    if (true) {
+        SrsResourceManager m("test");
+        HELPER_EXPECT_SUCCESS(m.start());
+
+        m.add_with_fast_id(101, new MockIDResource(1));
+        m.add_with_fast_id(102, new MockIDResource(2));
+        m.add_with_fast_id(103, new MockIDResource(3));
+        EXPECT_EQ(1, ((MockIDResource*)m.find_by_fast_id(101))->id);
+        EXPECT_EQ(2, ((MockIDResource*)m.find_by_fast_id(102))->id);
+        EXPECT_EQ(3, ((MockIDResource*)m.find_by_fast_id(103))->id);
+    }
+
+    if (true) {
+        SrsResourceManager m("test");
+        HELPER_EXPECT_SUCCESS(m.start());
+
+        MockIDResource* r1 = new MockIDResource(1);
+        MockIDResource* r2 = new MockIDResource(2);
+        MockIDResource* r3 = new MockIDResource(3);
+        m.add_with_fast_id(101, r1);
+        m.add_with_fast_id(102, r2);
+        m.add_with_fast_id(103, r3);
+        EXPECT_EQ(1, ((MockIDResource*)m.find_by_fast_id(101))->id);
+        EXPECT_EQ(2, ((MockIDResource*)m.find_by_fast_id(102))->id);
+        EXPECT_EQ(3, ((MockIDResource*)m.find_by_fast_id(103))->id);
+
+        m.remove(r2); srs_usleep(0);
+        EXPECT_TRUE(m.find_by_fast_id(102) == NULL);
+    }
+
+    if (true) {
+        SrsResourceManager m("test");
+        HELPER_EXPECT_SUCCESS(m.start());
+
+        MockIDResource* r1 = new MockIDResource(1);
+        MockIDResource* r2 = new MockIDResource(2);
+        MockIDResource* r3 = new MockIDResource(3);
+        m.add_with_fast_id(1, r1);
+        m.add_with_fast_id(100001, r2);
+        m.add_with_fast_id(1000001, r3);
+        EXPECT_EQ(1, ((MockIDResource*)m.find_by_fast_id(1))->id);
+        EXPECT_EQ(2, ((MockIDResource*)m.find_by_fast_id(100001))->id);
+        EXPECT_EQ(3, ((MockIDResource*)m.find_by_fast_id(1000001))->id);
+
+        m.remove(r2); srs_usleep(0);
+        EXPECT_TRUE(m.find_by_fast_id(100001) == NULL);
+
+        m.remove(r3); srs_usleep(0);
+        EXPECT_TRUE(m.find_by_fast_id(1000001) == NULL);
+
+        m.remove(r1); srs_usleep(0);
+        EXPECT_TRUE(m.find_by_fast_id(1) == NULL);
+    }
+
+    if (true) {
+        SrsResourceManager m("test");
+        HELPER_EXPECT_SUCCESS(m.start());
+
+        m.add_with_fast_id(101, new MockIDResource(1));
+        m.add_with_fast_id(10101, new MockIDResource(2));
+        m.add_with_fast_id(1010101, new MockIDResource(3));
+        m.add_with_fast_id(101010101, new MockIDResource(4));
+        m.add_with_fast_id(10101010101LL, new MockIDResource(5));
+        m.add_with_fast_id(1010101010101LL, new MockIDResource(6));
+        m.add_with_fast_id(101010101010101LL, new MockIDResource(7));
+        m.add_with_fast_id(10101010101010101LL, new MockIDResource(8));
+        m.add_with_fast_id(1010101010101010101ULL, new MockIDResource(9));
+        m.add_with_fast_id(11010101010101010101ULL, new MockIDResource(10));
+        EXPECT_EQ(1, ((MockIDResource*)m.find_by_fast_id(101))->id);
+        EXPECT_EQ(2, ((MockIDResource*)m.find_by_fast_id(10101))->id);
+        EXPECT_EQ(3, ((MockIDResource*)m.find_by_fast_id(1010101))->id);
+        EXPECT_EQ(4, ((MockIDResource*)m.find_by_fast_id(101010101))->id);
+        EXPECT_EQ(5, ((MockIDResource*)m.find_by_fast_id(10101010101LL))->id);
+        EXPECT_EQ(6, ((MockIDResource*)m.find_by_fast_id(1010101010101LL))->id);
+        EXPECT_EQ(7, ((MockIDResource*)m.find_by_fast_id(101010101010101LL))->id);
+        EXPECT_EQ(8, ((MockIDResource*)m.find_by_fast_id(10101010101010101LL))->id);
+        EXPECT_EQ(9, ((MockIDResource*)m.find_by_fast_id(1010101010101010101ULL))->id);
+        EXPECT_EQ(10, ((MockIDResource*)m.find_by_fast_id(11010101010101010101ULL))->id);
+    }
+
+    if (true) {
+        SrsResourceManager m("test");
+        HELPER_EXPECT_SUCCESS(m.start());
+
+        m.add_with_fast_id(101, new MockIDResource(1));
+        m.add_with_fast_id(101, new MockIDResource(4));
+        EXPECT_EQ(1, ((MockIDResource*)m.find_by_fast_id(101))->id);
+    }
+}
 
 VOID TEST(AppCoroutineTest, Dummy)
 {