diff --git a/c_src/bdberl_drv.c b/c_src/bdberl_drv.c
index fb12cdc..99c1f48 100644
--- a/c_src/bdberl_drv.c
+++ b/c_src/bdberl_drv.c
@@ -22,6 +22,8 @@
 static int open_database(const char* name, DBTYPE type, unsigned flags, PortData* data, int* errno);
 static int close_database(int dbref, unsigned flags, PortData* data);
 
+static void tune_system(int target, void* values, BinHelper* bh);
+
 static void do_async_put(void* arg);
 static void do_async_get(void* arg);
 static void do_async_txnop(void* arg);
@@ -113,7 +115,7 @@ static TPool* G_TPOOL_TXNS;
 #define UNPACK_STRING(_buf, _off) (char*)(_buf+(_off))
 #define UNPACK_BLOB(_buf, _off) (void*)(_buf+(_off))
 
-#define RETURN_BH(bh, outbuf) *outbuf = (char*)bh.bin; return bh.bin->orig_size;
+#define RETURN_BH(bh, outbuf) *outbuf = (char*)bh.bin; return bh.offset;
 
 #define RETURN_INT(val, outbuf) {             \
         BinHelper bh;                         \
@@ -137,6 +139,7 @@ DRIVER_INIT(bdberl_drv)
     // Initialize global environment -- use environment variable DB_HOME to 
     // specify where the working directory is
     db_env_create(&G_DB_ENV, 0);
+
     G_DB_ENV_ERROR = G_DB_ENV->open(G_DB_ENV, 0, flags, 0);
     if (G_DB_ENV_ERROR == 0)
     {
@@ -449,6 +452,20 @@ static int bdberl_drv_control(ErlDrvData handle, unsigned int cmd,
             RETURN_INT(ERROR_INVALID_DBREF, outbuf);
         }
     }        
+    case CMD_TUNE:
+    {
+        // Inbuf is: << Target:32, Values/binary >>
+        int target = UNPACK_INT(inbuf, 0);
+        char* values = UNPACK_BLOB(inbuf, 4);
+
+        // Setup a binhelper
+        BinHelper bh;
+
+        // Execute the tuning -- the result to send back to the caller is wrapped
+        // up in the provided binhelper
+        tune_system(target, values, &bh);
+        RETURN_BH(bh, outbuf);
+    }
     }
     *outbuf = 0;
     return 0;
@@ -703,6 +720,56 @@ static int close_database(int dbref, unsigned flags, PortData* data)
     return 0;
 }
 
+/**
+ * Given a target system parameter/action adjust/return the requested value
+ */
+static void tune_system(int target, void* values, BinHelper* bh)
+{
+    switch(target) 
+    {
+    case SYSP_CACHESIZE_SET:
+    {
+        unsigned int gbytes = UNPACK_INT(values, 0);
+        unsigned int bytes = UNPACK_INT(values, 4);
+        unsigned int ncache = UNPACK_INT(values, 8);
+        int rc = G_DB_ENV->set_cachesize(G_DB_ENV, gbytes, bytes, ncache);
+        bin_helper_init(bh, 4);
+        bin_helper_push_int32(bh, rc);
+        break;
+    }
+    case SYSP_CACHESIZE_GET:
+    {
+        unsigned int gbytes = 0;
+        unsigned int bytes = 0;
+        int caches = 0;
+        int rc = G_DB_ENV->get_cachesize(G_DB_ENV, &gbytes, &bytes, &caches);
+        bin_helper_init(bh, 16);
+        bin_helper_push_int32(bh, rc);
+        bin_helper_push_int32(bh, gbytes);
+        bin_helper_push_int32(bh, bytes);
+        bin_helper_push_int32(bh, caches);
+        break;
+    }
+    case SYSP_TXN_TIMEOUT_SET:
+    {
+        unsigned int timeout = UNPACK_INT(values, 0);
+        int rc = G_DB_ENV->set_timeout(G_DB_ENV, timeout, DB_SET_TXN_TIMEOUT);
+        bin_helper_init(bh, 4);
+        bin_helper_push_int32(bh, rc);
+        break;
+    }
+    case SYSP_TXN_TIMEOUT_GET:
+    {
+        unsigned int timeout = 0;
+        int rc = G_DB_ENV->get_timeout(G_DB_ENV, &timeout, DB_SET_TXN_TIMEOUT);
+        bin_helper_init(bh, 8);
+        bin_helper_push_int32(bh, rc);
+        bin_helper_push_int32(bh, timeout);
+        break;
+    }
+    }
+}
+
 static void do_async_put(void* arg)
 {
     // Payload is: <<DbRef:32, Flags:32, KeyLen:32, Key:KeyLen, ValLen:32, Val:ValLen>>
diff --git a/c_src/bdberl_drv.h b/c_src/bdberl_drv.h
index 582b702..66ce577 100644
--- a/c_src/bdberl_drv.h
+++ b/c_src/bdberl_drv.h
@@ -38,7 +38,8 @@ static void bdberl_drv_ready_input(ErlDrvData handle, ErlDrvEvent ev);
 #define CMD_TXN_ABORT        5
 #define CMD_GET              6
 #define CMD_PUT              7
-#define CMD_PUT_ATOMIC       8
+#define CMD_TUNE             8
+
 
 /**
  * Command status values
@@ -62,6 +63,19 @@ static void bdberl_drv_ready_input(ErlDrvData handle, ErlDrvEvent ev);
 #define ERROR_TXN_OPEN      (-29003) /* Transaction already active on this port */
 #define ERROR_NO_TXN        (-29004) /* No transaction open on this port */
 
+
+/**
+ * Tunable system parameters/actions
+ */
+#define SYSP_CACHESIZE_SET               0
+#define SYSP_CACHESIZE_GET               1
+#define SYSP_TXN_TIMEOUT_SET             2
+#define SYSP_TXN_TIMEOUT_GET             3
+#define SYSP_TXN_TIMEOUT             1
+#define SYSP_DEADLOCK_CHECK_INTERVAL 2
+#define SYSP_TRICKLE_INTERVAL        3
+#define SYSP_TRICKLE_PERCENTAGE      4
+
 /** 
  * Driver Entry
  */
diff --git a/src/bdberl_port.erl b/src/bdberl_port.erl
index 234a696..ae9cdf4 100644
--- a/src/bdberl_port.erl
+++ b/src/bdberl_port.erl
@@ -11,6 +11,8 @@
          close_database/2,
          txn_begin/1, txn_begin/2, 
          txn_commit/1, txn_commit/2, txn_abort/1,
+         get_cache_size/1, set_cache_size/4,
+         get_txn_timeout/1, set_txn_timeout/2,
          put/4, put/5,
          get/3, get/4]).
 
@@ -22,11 +24,16 @@
 -define(CMD_TXN_ABORT,  5).
 -define(CMD_GET,        6).
 -define(CMD_PUT,        7).
--define(CMD_PUT_ATOMIC, 8).
+-define(CMD_TUNE,       8).
 
 -define(DB_TYPE_BTREE, 1).
 -define(DB_TYPE_HASH,  2).
 
+-define(SYSP_CACHESIZE_SET,   0).
+-define(SYSP_CACHESIZE_GET,   1).
+-define(SYSP_TXN_TIMEOUT_SET, 2).
+-define(SYSP_TXN_TIMEOUT_GET, 3).
+
 %% DB API flags
 -define(DB_AGGRESSIVE,               16#00000001).
 -define(DB_ARCH_ABS,                 16#00000001).
@@ -368,6 +375,49 @@ get(Port, DbRef, Key, Opts) ->
         Error ->
             {error, {get, decode_rc(Error)}}
     end.
+
+get_cache_size(Port) ->    
+    Cmd = <<?SYSP_CACHESIZE_GET:32/native>>,
+    <<Result:32/signed-native, Gbytes:32/native, Bytes:32/native, Ncaches:32/native>> = 
+        erlang:port_control(Port, ?CMD_TUNE, Cmd),
+    case Result of
+        0 ->
+            {ok, Gbytes, Bytes, Ncaches};
+        _ ->
+            {error, Result}
+    end.
+
+set_cache_size(Port, Gbytes, Bytes, Ncaches) ->
+    Cmd = <<?SYSP_CACHESIZE_SET:32/native, Gbytes:32/native, Bytes:32/native, Ncaches:32/native>>,
+    <<Result:32/signed-native>> = erlang:port_control(Port, ?CMD_TUNE, Cmd),
+    case Result of
+        0 ->
+            ok;
+        _ ->
+            {error, Result}
+    end.
+    
+
+get_txn_timeout(Port) ->    
+    Cmd = <<?SYSP_TXN_TIMEOUT_GET:32/native>>,
+    <<Result:32/signed-native, Timeout:32/native>> = erlang:port_control(Port, ?CMD_TUNE, Cmd),
+    case Result of
+        0 ->
+            {ok, Timeout};
+        _ ->
+            {error, Result}
+    end.
+
+set_txn_timeout(Port, Timeout) ->
+    Cmd = <<?SYSP_TXN_TIMEOUT_SET:32/native, Timeout:32/native>>,
+    <<Result:32/signed-native>> = erlang:port_control(Port, ?CMD_TUNE, Cmd),
+    case Result of
+        0 ->
+            ok;
+        _ ->
+            {error, Result}
+    end.
+    
     
             
 %% ====================================================================
diff --git a/test/port_SUITE.erl b/test/port_SUITE.erl
index dddc135..38d7405 100644
--- a/test/port_SUITE.erl
+++ b/test/port_SUITE.erl
@@ -9,8 +9,8 @@
 -compile(export_all).
 
 all() ->
-%    [test_db].
-    [test_put].% test_txn].
+%    [test_db, test_put, test_txn, test_tune].
+    [test_tune].
 
 init_per_testcase(_TestCase, Config) ->
     Config.
@@ -71,3 +71,13 @@ test_txn(_Config) ->
     ok = bdberl_port:txn_begin(P),
     not_found = bdberl_port:get(P, 0, akey),
     ok = bdberl_port:txn_commit(P).
+
+test_tune(_Config) ->
+    {ok, P} = bdberl_port:new(),
+    
+    % Test transaction timeouts
+    {ok, 500000} = bdberl_port:get_txn_timeout(P),
+    ok = bdberl_port:set_txn_timeout(P, 250000),
+    {ok, 250000} = bdberl_port:get_txn_timeout(P).
+    
+