diff --git a/monkey/monkey.py b/monkey/monkey.py
index 653970728..37e5e4440 100644
--- a/monkey/monkey.py
+++ b/monkey/monkey.py
@@ -1,21 +1,17 @@
-import keydb
 import random
-import sched, time
+import time
 import socket
 import asyncore
 import threading
-import sys
+import argparse
 from pprint import pprint
 
-# Parameters
-numclients = 50
-#numkeys = 1000000
-numkeys  = 100000
-
 # Globals
-ops=0
-s = sched.scheduler(time.time, time.sleep)
-g_exit = False
+ops = {}
+numclients = 0
+numkeys = 0
+runtime = 0
+clients = []
 
 def _buildResp(*args):
     result = "*" + str(len(args)) + "\r\n"
@@ -32,6 +28,8 @@ class Client(asyncore.dispatcher):
         self.buf = b''
         self.inbuf = b''
         self.callbacks = list()
+        self.client_id = 0
+        self.get_client_id()
 
     def handle_connect(self):
         pass
@@ -55,6 +53,9 @@ class Client(asyncore.dispatcher):
         endrange = self.inbuf[startpos+1:].find(ord('\r')) + 1 + startpos
         assert(endrange > 0)
         numargs = int(self.inbuf[startpos+1:endrange])
+        if numargs == -1: # Nil array, used in some returns
+            startpos = endrange + 2
+            return startpos, []
         assert(numargs > 0)
         args = list()
         startpos = endrange + 2 # plus 1 gets us to the '\n' and the next gets us to the start char
@@ -127,10 +128,18 @@ class Client(asyncore.dispatcher):
         self.buf += _buildResp("lpush", key, val)
         self.callbacks.append(callback)
 
+    def blpop(self, *keys, timeout=0, callback=default_result_handler):
+        self.buf += _buildResp("blpop", *keys, str(timeout))
+        self.callbacks.append(callback)
+
     def delete(self, key, callback = default_result_handler):
         self.buf += _buildResp("del", key)
         self.callbacks.append(callback)
 
+    def unblock(self, client_id, callback=default_result_handler):
+        self.buf += _buildResp("client", "unblock", str(client_id))
+        self.callbacks.append(callback)
+
     def scan(self, iter, match=None, count=None, callback = default_result_handler):
         args = ["scan", str(iter)]
         if match != None:
@@ -142,68 +151,133 @@ class Client(asyncore.dispatcher):
         self.buf += _buildResp(*args)
         self.callbacks.append(callback)
 
+    def get_client_id(self):
+        self.buf += _buildResp("client", "id")
+        self.callbacks.append(self.store_client_id)
+
+    def store_client_id(self, c, resp):
+        assert(resp[0] == ord(':'))
+        self.client_id = int(resp[1:])
+        assert(self.client_id == c.client_id)
+
     def get(self, key, callback = None):
        return 
 
-
 def getrandomkey():
     return str(random.randrange(0, numkeys))
 
-def handle_lpush_response(c, resp):
+def handle_lpush_response(c, resp=None):
     global ops
     if resp != None:
-        ops = ops + 1
+        ops['lpush'] += 1
         assert(resp[0] == ord(':'))
     c.lpush("list_" + getrandomkey(), 'bardsklfjkldsjfdlsjflksdfjklsdjflksd kldsjflksd jlkdsjf lksdjklds jrfklsdjfklsdjfkl', handle_lpush_response)
 
-def handle_set_response(c, resp):
+def handle_blpop_response(c, resp=None):
     global ops
     if resp != None:
-        ops = ops + 1
+        ops['blpop'] += 1
+    c.blpop("list_" + getrandomkey(), callback=handle_blpop_response)
+
+def handle_set_response(c, resp=None):
+    global ops
+    if resp != None:
+        ops['set'] += 1
         assert(resp[0] == ord('+'))
     c.set("str_" + getrandomkey(), 'bardsklfjkldsjfdlsjflksdfjklsdjflksd kldsjflksd jlkdsjf lksdjklds jrfklsdjfklsdjfkl', handle_set_response)
 
-def handle_del_response(c, resp):
+def handle_del_response(c, resp=None):
     global ops
     if resp != None:
-        ops = ops + 1
+        ops['del'] += 1
     c.delete("list_" + getrandomkey(), handle_del_response)
 
-def scan_callback(c, resp):
+def scan_callback(c, resp=None):
     global ops
     nextstart = int(resp[0])
     c.scan(nextstart, count=500, callback=scan_callback)
-    ops = ops+1
+    ops['scan'] += 1
+
+def clear_ops():
+    global ops
+    ops = {'lpush': 0, 'blpop': 0, 'del': 0, 'scan': 0, 'set': 0, 'get': 0}
 
 def stats_thread():
     global ops
-    global g_exit
-    while not g_exit:
+    global runtime
+    i = 0
+    while i < runtime or not runtime:
         time.sleep(1)
-        print("Ops per second: " + str(ops))
-        ops = 0
+        print("Ops per second: " + str({k:v for (k,v) in ops.items() if v}))
+        clear_ops()
+        i += 1
+    asyncore.close_all()
 
-def main():
-    global g_exit
-    clients = []
+def flush_db_sync():
+    server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    server.connect(('127.0.0.1', 6379))
+    server.send(_buildResp("flushdb"))
+    resp = server.recv(8192)
+    assert(resp[:3] == "+OK".encode('utf-8'))
 
+def init_blocking():
+    global clients
+    if numkeys > 100 * numclients:
+        print("WARNING: High ratio of keys to clients. Most lpushes will not be popped and unblocking will take a long time!")
+    for i in range(numclients):
+        clients.append(Client('127.0.0.1', 6379))
+        if i % 2:
+            handle_blpop_response(clients[-1])
+        else:
+            handle_lpush_response(clients[-1])
+
+def init_lpush():
+    global clients
     for i in range(numclients):
         clients.append(Client('127.0.0.1', 6379))
         for i in range (10):
-            handle_lpush_response(clients[-1], None)
+            handle_lpush_response(clients[-1])
         #handle_set_response(clients[-1], None)
 
     scan_client = Client('127.0.0.1', 6379)
     scan_client.scan(0, count=500, callback=scan_callback)
 
     del_client = Client('127.0.0.1', 6379)
-    handle_del_response(del_client, None)
+    handle_del_response(del_client)
+
+def main(test, flush):
+    clear_ops()
+
+    if flush:
+        flush_db_sync()
+
+    try:
+        globals()[f"init_{test}"]()
+    except KeyError:
+        print(f"Test \"{test}\" not found. Exiting...")
+        exit()
+    except ConnectionRefusedError:
+        print("Could not connect to server. Is it running?")
+        print("Exiting...")
+        exit()
 
     threading.Thread(target=stats_thread).start()
     asyncore.loop()
-    g_exit = True
-    sys.exit(0)
-    print("DONE")
+    print("Done.")
+
+parser = argparse.ArgumentParser(description="Test use cases for KeyDB.")
+parser.add_argument('test', choices=[x[5:] for x in filter(lambda name: name.startswith("init_"), globals().keys())], help="which test to run")
+parser.add_argument('-c', '--clients', type=int, default=50, help="number of running clients to use")
+parser.add_argument('-k', '--keys', type=int, default=100000, help="number of keys to choose from for random tests")
+parser.add_argument('-t', '--runtime', type=int, default=0, help="how long to run the test for (default: 0 for infinite)")
+parser.add_argument('-f', '--flush', action="store_true", help="flush the db before running the test")
 
 if __name__ == "__main__":
-    main()
+    try:
+        args = parser.parse_args()
+    except:
+        exit()
+    numclients = args.clients
+    numkeys = args.keys
+    runtime = args.runtime
+    main(args.test, args.flush)
diff --git a/src/AsyncWorkQueue.cpp b/src/AsyncWorkQueue.cpp
index dae36cc06..fe02e5212 100644
--- a/src/AsyncWorkQueue.cpp
+++ b/src/AsyncWorkQueue.cpp
@@ -18,14 +18,15 @@ void AsyncWorkQueue::WorkerThreadMain()
 
     vars.clients_pending_asyncwrite = listCreate();
 
-    aeAcquireLock();
+    m_mutex.lock();
     m_vecpthreadVars.push_back(&vars);
-    aeReleaseLock();
+    m_mutex.unlock();
 
     while (!m_fQuitting)
     {
         std::unique_lock<std::mutex> lock(m_mutex);
-        m_cvWakeup.wait(lock);
+        if (m_workqueue.empty())
+            m_cvWakeup.wait(lock);
 
         while (!m_workqueue.empty())
         {
@@ -41,9 +42,11 @@ void AsyncWorkQueue::WorkerThreadMain()
 
         lock.unlock();
         serverTL->gcEpoch = g_pserver->garbageCollector.startEpoch();
-        aeAcquireLock();
-        ProcessPendingAsyncWrites();
-        aeReleaseLock();
+        if (listLength(serverTL->clients_pending_asyncwrite)) {
+            aeAcquireLock();
+            ProcessPendingAsyncWrites();
+            aeReleaseLock();
+        }
         g_pserver->garbageCollector.endEpoch(serverTL->gcEpoch);
         serverTL->gcEpoch.reset();
     }
@@ -60,6 +63,7 @@ bool AsyncWorkQueue::removeClientAsyncWrites(client *c)
 {
     bool fFound = false;
     aeAcquireLock();
+    m_mutex.lock();
     for (auto pvars : m_vecpthreadVars)
     {
         listIter li;
@@ -74,6 +78,7 @@ bool AsyncWorkQueue::removeClientAsyncWrites(client *c)
             }
         }
     }
+    m_mutex.unlock();
     aeReleaseLock();
     return fFound;
 }
diff --git a/src/IStorage.h b/src/IStorage.h
index 69611de13..d5808c4c1 100644
--- a/src/IStorage.h
+++ b/src/IStorage.h
@@ -1,5 +1,6 @@
 #pragma once
 #include <functional>
+#include "sds.h"
 
 class IStorageFactory
 {
@@ -28,6 +29,14 @@ public:
     virtual bool enumerate(callback fn) const = 0;
     virtual size_t count() const = 0;
 
+    virtual void bulkInsert(sds *rgkeys, sds *rgvals, size_t celem) {
+        beginWriteBatch();
+        for (size_t ielem = 0; ielem < celem; ++ielem) {
+            insert(rgkeys[ielem], sdslen(rgkeys[ielem]), rgvals[ielem], sdslen(rgvals[ielem]), false);
+        }
+        endWriteBatch();
+    }
+
     virtual void beginWriteBatch() {} // NOP
     virtual void endWriteBatch() {} // NOP
 
diff --git a/src/StorageCache.cpp b/src/StorageCache.cpp
index 7f86b595e..29908c7f5 100644
--- a/src/StorageCache.cpp
+++ b/src/StorageCache.cpp
@@ -91,6 +91,20 @@ void StorageCache::insert(sds key, const void *data, size_t cbdata, bool fOverwr
     m_spstorage->insert(key, sdslen(key), (void*)data, cbdata, fOverwrite);
 }
 
+void StorageCache::bulkInsert(sds *rgkeys, sds *rgvals, size_t celem)
+{
+    std::unique_lock<fastlock> ul(m_lock);
+    bulkInsertsInProgress++;
+    if (m_pdict != nullptr) {
+        for (size_t ielem = 0; ielem < celem; ++ielem) {
+            cacheKey(rgkeys[ielem]);
+        }
+    }
+    ul.unlock();
+    m_spstorage->bulkInsert(rgkeys, rgvals, celem);
+    bulkInsertsInProgress--;
+}
+
 const StorageCache *StorageCache::clone()
 {
     std::unique_lock<fastlock> ul(m_lock);
@@ -119,7 +133,7 @@ size_t StorageCache::count() const
     std::unique_lock<fastlock> ul(m_lock);
     size_t count = m_spstorage->count();
     if (m_pdict != nullptr) {
-        serverAssert(count == (dictSize(m_pdict) + m_collisionCount));
+        serverAssert(bulkInsertsInProgress.load(std::memory_order_seq_cst) || count == (dictSize(m_pdict) + m_collisionCount));
     }
     return count;
 }
diff --git a/src/StorageCache.h b/src/StorageCache.h
index c2170b7d0..ed868e74b 100644
--- a/src/StorageCache.h
+++ b/src/StorageCache.h
@@ -7,6 +7,7 @@ class StorageCache
     dict *m_pdict = nullptr;
     int m_collisionCount = 0;
     mutable fastlock m_lock {"StorageCache"};
+    std::atomic<int> bulkInsertsInProgress;
 
     StorageCache(IStorage *storage, bool fNoCache);
 
@@ -37,6 +38,7 @@ public:
 
     void clear();
     void insert(sds key, const void *data, size_t cbdata, bool fOverwrite);
+    void bulkInsert(sds *rgkeys, sds *rgvals, size_t celem);
     void retrieve(sds key, IStorage::callbackSingle fn) const;
     bool erase(sds key);
 
@@ -50,4 +52,4 @@ public:
     size_t count() const;
 
     const StorageCache *clone();
-};
\ No newline at end of file
+};
diff --git a/src/dict.cpp b/src/dict.cpp
index 57872b5c4..d16fd77f7 100644
--- a/src/dict.cpp
+++ b/src/dict.cpp
@@ -535,7 +535,8 @@ dictAsyncRehashCtl::~dictAsyncRehashCtl() {
     while (deGCList != nullptr) {
         auto next = deGCList->next;
         dictFreeKey(dict, deGCList);
-        dictFreeVal(dict, deGCList);
+        if (deGCList->v.val != nullptr)
+            dictFreeVal(dict, deGCList);
         zfree(deGCList);
         deGCList = next;
     }
@@ -694,6 +695,8 @@ static dictEntry *dictGenericDelete(dict *d, const void *key, int nofree) {
                     d->ht[table].table[idx] = he->next;
                 if (!nofree) {
                     if (table == 0 && d->asyncdata != nullptr && (ssize_t)idx < d->rehashidx) {
+                        dictFreeVal(d, he);
+                        he->v.val = nullptr;
                         he->next = d->asyncdata->deGCList;
                         d->asyncdata->deGCList = he;
                     } else {
@@ -752,6 +755,8 @@ void dictFreeUnlinkedEntry(dict *d, dictEntry *he) {
     if (he == NULL) return;
 
     if (d->asyncdata) {
+        dictFreeVal(d, he);
+        he->v.val = nullptr;
         he->next = d->asyncdata->deGCList;
         d->asyncdata->deGCList = he;
     } else { 
@@ -775,6 +780,8 @@ int _dictClear(dict *d, dictht *ht, void(callback)(void *)) {
         while(he) {
             nextHe = he->next;
             if (d->asyncdata && (ssize_t)i < d->rehashidx) {
+                dictFreeVal(d, he);
+                he->v.val = nullptr;
                 he->next = d->asyncdata->deGCList;
                 d->asyncdata->deGCList = he;
             } else {
diff --git a/src/storage/rocksdb.cpp b/src/storage/rocksdb.cpp
index 1d6f943b4..a598c2a35 100644
--- a/src/storage/rocksdb.cpp
+++ b/src/storage/rocksdb.cpp
@@ -38,6 +38,17 @@ void RocksDBStorageProvider::insert(const char *key, size_t cchKey, void *data,
         ++m_count;
 }
 
+void RocksDBStorageProvider::bulkInsert(sds *rgkeys, sds *rgvals, size_t celem)
+{
+    auto spbatch = std::make_unique<rocksdb::WriteBatch>();
+    for (size_t ielem = 0; ielem < celem; ++ielem) {
+        spbatch->Put(m_spcolfamily.get(), rocksdb::Slice(rgkeys[ielem], sdslen(rgkeys[ielem])), rocksdb::Slice(rgvals[ielem], sdslen(rgvals[ielem])));
+    }
+    m_spdb->Write(WriteOptions(), spbatch.get());
+    std::unique_lock<fastlock> l(m_lock);
+    m_count += celem;
+}
+
 bool RocksDBStorageProvider::erase(const char *key, size_t cchKey)
 {
     rocksdb::Status status;
diff --git a/src/storage/rocksdb.h b/src/storage/rocksdb.h
index 4a0665b6e..48be6984f 100644
--- a/src/storage/rocksdb.h
+++ b/src/storage/rocksdb.h
@@ -34,6 +34,8 @@ public:
     virtual void beginWriteBatch() override;
     virtual void endWriteBatch() override;
 
+    virtual void bulkInsert(sds *rgkeys, sds *rgvals, size_t celem) override;
+
     virtual void batch_lock() override;
     virtual void batch_unlock() override;
 
diff --git a/tests/unit/memefficiency.tcl b/tests/unit/memefficiency.tcl
index 4ee6fdbdb..db18e7128 100644
--- a/tests/unit/memefficiency.tcl
+++ b/tests/unit/memefficiency.tcl
@@ -395,7 +395,7 @@ start_server {tags {"defrag"} overrides {appendonly yes auto-aof-rewrite-percent
             # if the current slab is lower in utilization the defragger would have ended up in stagnation,
             # keept running and not move any allocation.
             # this test is more consistent on a fresh server with no history
-            start_server {tags {"defrag"} overrides {save ""}} {
+            start_server {tags {"defrag"} overrides {save "" server-threads 1}} {
                 r flushdb
                 r config resetstat
                 r config set hz 100