diff --git a/README.rst b/README.rst
index 146f689..c629967 100644
--- a/README.rst
+++ b/README.rst
@@ -54,6 +54,13 @@ TODO
 changelog
 ---------
 
+v. 0.9.2
+''''''''
+
+-  todo queue and done list backends
+-  created very slowest sqlite backend for todo queue and done lists (1000 url writing for 3 minutes)
+-  tests for sqlite_todo backend
+
 v. 0.9.1
 ''''''''
 
diff --git a/pysitemap/__init__.py b/pysitemap/__init__.py
index 2729498..afbfe71 100644
--- a/pysitemap/__init__.py
+++ b/pysitemap/__init__.py
@@ -21,7 +21,7 @@ def crawler(root_url, out_file, out_format='xml', maxtasks=100):
         loop.add_signal_handler(signal.SIGINT, loop.stop)
     except RuntimeError:
         pass
-    print('todo:', len(c.todo))
+    print('todo_queue:', len(c.todo_queue))
     print('busy:', len(c.busy))
     print('done:', len(c.done), '; ok:', sum(c.done.values()))
     print('tasks:', len(c.tasks))
\ No newline at end of file
diff --git a/pysitemap/backends/__init__.py b/pysitemap/backends/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/pysitemap/backends/sqlite_todo.py b/pysitemap/backends/sqlite_todo.py
new file mode 100644
index 0000000..689c4e6
--- /dev/null
+++ b/pysitemap/backends/sqlite_todo.py
@@ -0,0 +1,83 @@
+import logging
+import sqlite3
+
+
+class SQLiteTodo(object):
+    def __init__(self, db_name):
+        self.connection = sqlite3.connect(db_name)
+        self.__init_tables()
+
+    def __init_tables(self):
+        cursor = self.connection.cursor()
+        cursor.execute("DROP TABLE IF EXISTS todo_queue;")
+        cursor.execute("""
+            CREATE TABLE todo_queue (
+                url text(1000) primary key
+            );
+        """)
+        self.connection.commit()
+        cursor.close()
+
+    def add(self, url):
+        cursor = self.connection.cursor()
+        try:
+            cursor.execute("""insert into todo_queue values (?);""", (url,))
+        except Exception as e:
+            logging.info(e)
+        finally:
+            self.connection.commit()
+            cursor.close()
+
+    def remove(self, url):
+        cursor = self.connection.cursor()
+        try:
+            cursor.execute("""delete from todo_queue where url = ?;""", (url,))
+        except Exception as e:
+            logging.info(e)
+        finally:
+            self.connection.commit()
+            cursor.close()
+
+    def __contains__(self, item):
+        cursor = self.connection.cursor()
+        result = False
+        try:
+            cursor.execute("""select 1 from todo_queue where url = ?""", (item, ))
+            row = cursor.fetchone()
+            if len(row):
+                result = True
+        except Exception as e:
+            logging.info(e)
+        finally:
+            cursor.close()
+        return result
+
+    def __iter__(self):
+        cursor = self.connection.cursor()
+        result = []
+        try:
+            cursor.execute("""select url from todo_queue""")
+            rows = cursor.fetchall()
+            result = [row[0] for row in rows]
+        except Exception as e:
+            logging.info(e)
+        finally:
+            cursor.close()
+        return iter(result)
+
+    def __next__(self):
+        for url in self:
+            yield url
+
+    def __len__(self):
+        cursor = self.connection.cursor()
+        result = []
+        try:
+            cursor.execute("""select count(*) as cnt from todo_queue""")
+            row = cursor.fetchone()
+            result = row[0]
+        except Exception as e:
+            logging.info(e)
+        finally:
+            cursor.close()
+        return result
\ No newline at end of file
diff --git a/pysitemap/base_crawler.py b/pysitemap/base_crawler.py
index 30ab28f..d282c32 100644
--- a/pysitemap/base_crawler.py
+++ b/pysitemap/base_crawler.py
@@ -14,7 +14,8 @@ class Crawler:
         'txt': TextWriter
     }
 
-    def __init__(self, rooturl, out_file, out_format='xml', maxtasks=100):
+    def __init__(self, rooturl, out_file, out_format='xml', maxtasks=100,
+                 todo_queue_backend=set, done_backend=dict):
         """
         Crawler constructor
         :param rooturl: root url of site
@@ -27,9 +28,9 @@ class Crawler:
         :type maxtasks: int
         """
         self.rooturl = rooturl
-        self.todo = set()
+        self.todo_queue = todo_queue_backend()
         self.busy = set()
-        self.done = {}
+        self.done = done_backend()
         self.tasks = set()
         self.sem = asyncio.Semaphore(maxtasks)
 
@@ -63,8 +64,8 @@ class Crawler:
             if (url.startswith(self.rooturl) and
                     url not in self.busy and
                     url not in self.done and
-                    url not in self.todo):
-                self.todo.add(url)
+                    url not in self.todo_queue):
+                self.todo_queue.add(url)
                 # Acquire semaphore
                 await self.sem.acquire()
                 # Create async task
@@ -85,7 +86,7 @@ class Crawler:
         print('processing:', url)
 
         # remove url from basic queue and add it into busy list
-        self.todo.remove(url)
+        self.todo_queue.remove(url)
         self.busy.add(url)
 
         try:
@@ -108,6 +109,6 @@ class Crawler:
 
         self.busy.remove(url)
         logging.info(len(self.done), 'completed tasks,', len(self.tasks),
-              'still pending, todo', len(self.todo))
+              'still pending, todo_queue', len(self.todo_queue))
 
 
diff --git a/run.py b/run.py
index b19ee9c..a8acbbe 100644
--- a/run.py
+++ b/run.py
@@ -11,5 +11,5 @@ if __name__ == '__main__':
         events.set_event_loop(el)
 
     # root_url = sys.argv[1]
-    root_url = 'http://www.haikson.ru'
+    root_url = 'https://www.metpromstroi.ru'
     crawler(root_url, out_file='sitemap.xml')
\ No newline at end of file
diff --git a/sitemap.xml b/sitemap.xml
index e69de29..23d5e1d 100644
--- a/sitemap.xml
+++ b/sitemap.xml
@@ -0,0 +1 @@
+<?xml version="1.0" encoding="utf-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9 http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">
<url><loc>https://www.metpromstroi.ru</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-content/plugins/otter-blocks/vendor/codeinwp/gutenberg-animation/assets/css/style.css?ver=5.3.2</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-content/plugins/embed-pdf-viewer/css/embed-pdf-viewer.css?ver=5.3.2</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-includes/css/dist/block-library/style.min.css?ver=5.3.2</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-content/plugins/contact-form-7/includes/css/styles.css?ver=5.1.6</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-includes/wlwmanifest.xml</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-content/plugins/otter-blocks/vendor/codeinwp/gutenberg-blocks/build/style.css?ver=1.3.4</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-content/plugins/otter-blocks/vendor/codeinwp/gutenberg-animation/assets/css/animate.min.css?ver=5.3.2</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-content/uploads/2019/05/cropped-angar2104191212-e1558883104684-32x32.jpg</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-content/uploads/2019/05/cropped-angar2104191212-e1558883104684-192x192.jpg</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-content/uploads/2019/05/cropped-angar2104191212-e1558883104684-180x180.jpg</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-content/themes/neve/style.min.css?ver=2.5.4</loc></url>
<url><loc>https://www.metpromstroi.ru/</loc></url>
<url><loc>https://www.metpromstroi.ru/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/comments/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/xmlrpc.php?rsd</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.metpromstroi.ru%2F</loc></url>
<url><loc>https://www.metpromstroi.ru/category/proizvodstvo/</loc></url>
<url><loc>https://www.metpromstroi.ru/category/company/</loc></url>
<url><loc>https://www.metpromstroi.ru/obratnaya-svyaz/</loc></url>
<url><loc>https://www.metpromstroi.ru/angary-i-sklady_pg/</loc></url>
<url><loc>https://www.metpromstroi.ru/kontakty/</loc></url>
<url><loc>https://www.metpromstroi.ru/zhivotnovodcheskie-kompleksy-i-fermy_pg/</loc></url>
<url><loc>https://www.metpromstroi.ru/sklady-i-raspredelitelnye-tsentry_pg/</loc></url>
<url><loc>https://www.metpromstroi.ru/avtomojki-i-sto_pg/</loc></url>
<url><loc>https://www.metpromstroi.ru/zernohranilishha_pg/</loc></url>
<url><loc>https://www.metpromstroi.ru/category/proizvodstvo/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/kioski-i-torgovye-pavilony_pg/</loc></url>
<url><loc>https://www.metpromstroi.ru/author/haikson/</loc></url>
<url><loc>https://www.metpromstroi.ru/category/company/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/svidetelstvo-sro_pg/</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.metpromstroi.ru%2Fobratnaya-svyaz%2F</loc></url>
<url><loc>https://www.metpromstroi.ru/angary-i-sklady_pg/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.metpromstroi.ru%2Fangary-i-sklady_pg%2F</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.metpromstroi.ru%2Fkontakty%2F</loc></url>
<url><loc>https://www.metpromstroi.ru/zhivotnovodcheskie-kompleksy-i-fermy_pg/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.metpromstroi.ru%2Fzhivotnovodcheskie-kompleksy-i-fermy_pg%2F</loc></url>
<url><loc>https://www.metpromstroi.ru/xmlrpc.php</loc></url>
<url><loc>https://www.metpromstroi.ru/sklady-i-raspredelitelnye-tsentry_pg/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/avtomojki-i-sto_pg/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/zernohranilishha_pg/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.metpromstroi.ru%2Fsklady-i-raspredelitelnye-tsentry_pg%2F</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.metpromstroi.ru%2Favtomojki-i-sto_pg%2F</loc></url>
<url><loc>https://www.metpromstroi.ru/kioski-i-torgovye-pavilony_pg/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.metpromstroi.ru%2Fzernohranilishha_pg%2F</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.metpromstroi.ru%2Fkioski-i-torgovye-pavilony_pg%2F</loc></url>
<url><loc>https://www.metpromstroi.ru/author/haikson/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/svidetelstvo-sro_pg/feed/</loc></url>
<url><loc>https://www.metpromstroi.ru/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.metpromstroi.ru%2Fsvidetelstvo-sro_pg%2F</loc></url>
<url><loc>https://www.metpromstroi.ru/?p=66</loc></url>
<url><loc>https://www.metpromstroi.ru/?p=1</loc></url>
<url><loc>https://www.metpromstroi.ru/?p=21</loc></url>
<url><loc>https://www.metpromstroi.ru/?p=46</loc></url>
<url><loc>https://www.metpromstroi.ru/?p=100</loc></url>
<url><loc>https://www.metpromstroi.ru/?p=53</loc></url>
<url><loc>https://www.metpromstroi.ru/?p=39</loc></url>
<url><loc>https://www.metpromstroi.ru/?p=61</loc></url>
<url><loc>https://www.metpromstroi.ru/?p=22</loc></url>
</urlset>
\ No newline at end of file
diff --git a/version.py b/version.py
index 7e91176..4d11208 100644
--- a/version.py
+++ b/version.py
@@ -1 +1 @@
-VERSION = '0.9.1'
\ No newline at end of file
+VERSION = '0.9.2'
\ No newline at end of file