diff --git a/bin/euscan b/bin/euscan
index 784daf9..8696848 100755
--- a/bin/euscan
+++ b/bin/euscan
@@ -128,7 +128,10 @@ def print_usage(_error=None, help=None):
         print(yellow(" -I, --ignore-pre-release-if-stable") +
             " - Ignore non-stable versions only if current\n" +
             " " * 38 + "version is stable", file=out)
-
+        print(yellow("     --mirror") +
+            "              - use mirror:// URIs", file=out)
+        print(yellow("     --ebuild-uri") +
+            "              - use ebuild variables in URIs", file=out)
         print(file=out)
 
     if _error in ('packages',) or help:
@@ -182,12 +185,14 @@ def parse_args():
                 pp.output.nocolor()
             elif o in ("-p", "--progress"):
                 CONFIG['progress'] = isatty
-            elif o in ("-m", "--mirror"):
+            elif o in ("--mirror"):
                 CONFIG['mirror'] = True
             elif o in ("-i", "--ignore-pre-release"):
                 CONFIG['ignore-pre-release'] = True
             elif o in ("-I", "--ignore-pre-release-if-stable"):
                 CONFIG['ignore-pre-release-if-stable'] = True
+            elif o in ("--ebuild-uri"):
+                CONFIG['ebuild-uri'] = True
             else:
                 return_code = False
 
@@ -195,11 +200,11 @@ def parse_args():
 
     # here are the different allowed command line options (getopt args)
     getopt_options = {'short': {}, 'long': {}}
-    getopt_options['short']['global'] = "hVCqv1bf:pmiI"
+    getopt_options['short']['global'] = "hVCqv1bf:piI"
     getopt_options['long']['global'] = [
         "help", "version", "nocolor", "quiet", "verbose", "oneshot",
         "brute-force=", "format=", "progress", "mirror", "ignore-pre-release",
-        "ignore-pre-release-if-stable",
+        "ignore-pre-release-if-stable", "ebuild-uri"
     ]
 
     short_opts = getopt_options['short']['global']
diff --git a/euscanwww/README.Celery b/euscanwww/README.Celery
index f2a5149..00884c5 100644
--- a/euscanwww/README.Celery
+++ b/euscanwww/README.Celery
@@ -9,7 +9,7 @@ or::
 
     python setup.py install  # to install euscan and requirements
 
-If you prefer to use portage just install dev-python/django-celery-2.5.5
+If you prefer to use portage just install dev-python/django-celery
 
 There's the need of having a broker for tasks. The default and reccommended
 broker is RabbitMQ.
diff --git a/euscanwww/djeuscan/processing/scan/scan_portage.py b/euscanwww/djeuscan/processing/scan/scan_portage.py
index 022cff0..b00c416 100644
--- a/euscanwww/djeuscan/processing/scan/scan_portage.py
+++ b/euscanwww/djeuscan/processing/scan/scan_portage.py
@@ -8,14 +8,12 @@ from xml.etree.ElementTree import iterparse, ParseError
 from django.db.transaction import commit_on_success
 from django.core.management.color import color_style
 
-from euscan.helpers import get_version_type
+from euscan.version import get_version_type
 
 from djeuscan.processing import FakeLogger
 from djeuscan.models import Package, Version, VersionLog
 
-
-PORTDB = portage.db[portage.root]["porttree"].dbapi
-
+PORTDB = None
 
 class ScanPortage(object):
     def __init__(self, logger=None, no_log=False, purge_packages=False,
@@ -25,6 +23,10 @@ class ScanPortage(object):
         self.purge_packages = purge_packages
         self.purge_versions = purge_versions
 
+        if not PORTDB: # Lazy loading for portdb
+            global PORTDB
+            PORTDB = portage.db[portage.root]["porttree"].dbapi
+
         self.style = color_style()
 
         self._cache = {'packages': {}, 'versions': {}}
@@ -342,9 +344,14 @@ def scan_portage(packages=None, category=None, no_log=False,
 
     if prefetch:
         logger.info('Prefetching objects...')
-        for package in Package.objects.all():
+        ppackages = Package.objects.all()
+        pversions = Version.objects.select_related('package').all()
+        if category:
+            ppackages = ppackages.filter(category=category)
+            pversions = pversions.filter(package__category=category)
+        for package in ppackages:
             scan_handler.cache_store_package(package)
-        for version in Version.objects.select_related('package').all():
+        for version in pversions:
             scan_handler.cache_store_version(version)
         logger.info('done')
 
diff --git a/euscanwww/djeuscan/processing/scan/scan_upstream.py b/euscanwww/djeuscan/processing/scan/scan_upstream.py
index e3ee86a..8461a25 100644
--- a/euscanwww/djeuscan/processing/scan/scan_upstream.py
+++ b/euscanwww/djeuscan/processing/scan/scan_upstream.py
@@ -153,9 +153,12 @@ def scan_upstream(packages=None, purge_versions=False,
 
     for pkg in packages:
         try:
-            scan_handler.scan('%s/%s' % (pkg.category, pkg.name))
+            package = '%s/%s' % (pkg.category, pkg.name)
         except AttributeError:
-            scan_handler.scan(pkg)
+            package = pkg
+
+        logger.info('Scanning %s' % package)
+        scan_handler.scan(package)
 
     scan_handler.purge_old_versions()
 
diff --git a/euscanwww/djeuscan/tasks.py b/euscanwww/djeuscan/tasks.py
index 86b5105..512ad91 100644
--- a/euscanwww/djeuscan/tasks.py
+++ b/euscanwww/djeuscan/tasks.py
@@ -9,10 +9,8 @@ from celery.task import task, group, chord
 from django.conf import settings
 
 from djeuscan.models import Package, RefreshPackageQuery
-from djeuscan.processing.misc import regen_rrds, update_counters, \
-    update_portage_trees
-from djeuscan.processing.scan import scan_metadata, scan_portage, scan_upstream
-
+from djeuscan.processing import scan, misc
+from djeuscan.utils import queryset_iterator
 
 class TaskFailedException(Exception):
     """
@@ -20,103 +18,85 @@ class TaskFailedException(Exception):
     """
     pass
 
-
-def _chunks(it, n):
+def group_one(task, seq, *args, **kwargs):
     """
-    Chunk generator, takes an iterator and the desired size of the chunk
+    Create a group of tasks, each task handle one element of seq
     """
-    for first in it:
-        yield [first] + list(islice(it, n - 1))
+    tasks = []
+    for i in seq:
+        tasks.append(task.subtask(args=[seq[i]] + list(args), kwargs=kwargs))
+    return group(tasks)
 
-
-def _run_in_chunks(task, packages, kwargs=None,
-                   concurrently=settings.TASKS_CONCURRENTLY,
-                   n=settings.TASKS_SUBTASK_PACKAGES):
+def group_chunks(task, seq, n, *args, **kwargs):
     """
-    Launches a group at a time with <concurrently> subtasks.
-    Each subtask has <n> packages to handle
+    Creates a group of tasks, each subtask has <n> elements to handle
     """
-    output = []
-
-    chunk_generator = _chunks(iter(packages), n)
-    done = False
-
-    while not done:
-        tasks = []
-        for _ in range(concurrently):
-            try:
-                chunk = chunk_generator.next()
-            except StopIteration:
-                done = True
-            else:
-                tasks.append(task.subtask((chunk, ), kwargs))
-        output.extend(group(tasks)())
-    return output
-
+    tasks = []
+    for i in xrange(0, len(seq), n):
+        tasks.append(task.subtask(args=[seq[i:i+n]] + list(args), kwargs=kwargs))
+    return group(tasks)
 
 @task
-def regen_rrds_task():
+def regen_rrds():
     """
     Regenerate RRDs
     """
-    return regen_rrds()
-
+    misc.regen_rrds()
+    return True
 
 @task
-def update_counters_task(fast=True):
+def update_counters(fast=False):
     """
     Updates counters
     """
-    return update_counters(fast=fast)
-
+    logger = update_counters.get_logger()
+    logger.info("Updating counters (fast=%s)...", fast)
+    misc.update_counters(fast=fast)
+    logger.info("Done")
+    return True
 
 @task
-def _scan_metadata_task(packages):
+def scan_metadata(packages=[], category=None):
     """
     Scans metadata for the given set of packages
     """
-    logger = _scan_metadata_task.get_logger()
-    logger.info("Starting metadata scanning subtask for %d packages...",
-                len(packages))
+    logger = scan_metadata.get_logger()
 
-    scan_metadata(
+    if packages:
+        logger.info("Starting metadata scan for %d packages...",
+                    len(packages))
+    elif category:
+        logger.info("Starting metadata scan for %s...",
+                    category)
+    else:
+        logger.info("Starting metadata scan...")
+
+    scan.scan_metadata(
         packages=packages,
+        category=category,
         logger=logger,
     )
-
+    return True
 
 @task
-def scan_metadata_list_task(query):
-    """
-    Runs a parallel metadata scan for packages in the query list (space
-    separated string). Task used only from the web interface.
-    """
-    return _run_in_chunks(_scan_metadata_task, [p for p in query.split()])
-
-
-@task
-def scan_metadata_all_task():
-    """
-    Runs a parallel metadata scan for all packages
-    """
-    return _run_in_chunks(_scan_metadata_task, Package.objects.all())
-
-
-@task
-def _scan_portage_task(packages, category=None, no_log=False,
-                       purge_packages=False, purge_versions=False,
-                       prefetch=False):
+def scan_portage(packages=[], category=None,
+                 no_log=False, purge_packages=False,
+                 purge_versions=False, prefetch=False):
     """
     Scans portage for the given set of packages
     """
-    logger = _scan_portage_task.get_logger()
-    if packages:
-        logger.info("Starting portage scanning subtask for %d packages...",
-                    len(packages))
-    else:
-        logger.info("Starting portage scanning for all packages...")
+    logger = scan_portage.get_logger()
 
-    scan_portage(
+    if packages:
+        logger.info("Starting portage scan for %d packages...",
+                    len(packages))
+    elif category:
+        logger.info("Starting portage scan for %s...",
+                    category)
+    else:
+        logger.info("Starting portage scan...")
+
+    scan.scan_portage(
         packages=packages,
         category=category,
         no_log=no_log,
@@ -125,131 +105,77 @@ def _scan_portage_task(packages, category=None, no_log=False,
         prefetch=prefetch,
         logger=logger,
     )
-
+    return True
 
 @task
-def scan_portage_list_task(query, no_log=False, purge_packages=False,
-                           purge_versions=False, prefetch=False):
-    """
-    Runs a parallel portage scan for packages in the query list (space
-    separated string). Task used only from the web interface.
-    """
-    kwargs = {"no_log": no_log, "purge_packages": purge_packages,
-              "purge_versions": purge_versions, "prefetch": prefetch}
-    return _run_in_chunks(
-        _scan_portage_task, [p for p in query.split()], kwargs
-    )
-
-
-@task
-def scan_portage_all_task(no_log=False, purge_packages=False,
-                          purge_versions=False, prefetch=False):
-    """
-    Runs a syncronous portage scan for all packages
-    """
-    _scan_portage_task(
-        packages=None,
-        category=None,
-        no_log=no_log,
-        purge_packages=purge_packages,
-        purge_versions=purge_versions,
-        prefetch=prefetch,
-    )
-
-
-@task
-def _scan_upstream_task(packages, purge_versions=False):
+def scan_upstream(packages=[], purge_versions=False):
     """
     Scans upstream for the given set of packages
     """
-    logger = _scan_upstream_task.get_logger()
+    logger = scan_upstream.get_logger()
 
-    logger.info("Starting upstream scanning subtask for %d packages...",
-                len(packages))
+    if len(packages):
+        logger.info("Starting upstream scan subtask for %d packages...",
+                    len(packages))
+    else:
+        logger.info("Starting upstream scan...",
+                    len(packages))
 
-    result = scan_upstream(
+    scan.scan_upstream(
         packages=packages,
         purge_versions=purge_versions,
         logger=logger,
     )
-    # TODO: implement some kind of error raising in case of failure
-    #if not result:
-    #    raise TaskFailedException
-    return result
-
+    return True
 
 @task
-def scan_upstream_list_task(query, purge_versions=False):
-    """
-    Runs a parallel upstream scan for packages in the query list (space
-    separated string). Task used only from the web interface.
-    """
-
-    kwargs = {"purge_versions": purge_versions}
-    return _run_in_chunks(_scan_upstream_task, [p for p in query.split()],
-                          kwargs)
-
-
-@task
-def scan_upstream_all_task(purge_versions=False):
-    """
-    Runs a parallel portage scan for all packages
-    """
-    kwargs = {"purge_versions": purge_versions}
-    return _run_in_chunks(
-        _scan_upstream_task,
-        Package.objects.all().order_by('?'),
-        kwargs
-    )
-
-
-@task
-def update_portage_trees_task():
+def update_portage_trees():
     """
     Update portage tree
     """
-    logger = update_portage_trees_task.get_logger()
-    update_portage_trees(logger=logger)
-
+    logger = update_portage_trees.get_logger()
+    misc.update_portage_trees(logger=logger)
+    return True
 
 @task
-def update_task(update_portage_trees=True, scan_portage=True,
-                scan_metadata=True, scan_upstream=True, update_counters=True):
-    """
-    Update the whole euscan system
-    """
-    if update_portage_trees:
-        update_portage_trees_task()
-    if scan_portage:
-        scan_portage_all_task(prefetch=True, purge_packages=True,
-                              purge_versions=True)
+def update_portage(packages=None):
+    (
+        update_portage_trees.s() |
+        scan_portage.si(purge_packages=True, purge_versions=True, prefetch=True) |
+        #scan_metadata.si() |
+        group_one(scan_metadata, portage.settings.categories) |
+        update_counters.si(fast=False)
+    )()
+    return True
 
-    # metadata and upstream scan can run concurrently, launch them
-    # in a group and wait for them to finish
-    tasks = []
-    if scan_metadata:
-        tasks.append(scan_metadata_all_task.subtask())
+@task
+def update_upstream():
+    if settings.TASKS_UPSTREAM_GROUPS >= 1:
+        packages = Package.objects.all()
 
-    if scan_upstream:
-        tasks.append(scan_upstream_all_task.subtask())
-
-    if update_counters:
-        chord(tasks)(
-            # immutable means that the result of previous tasks is not passed
-            update_counters_task.subtask((), {"fast": False}, immutable=True)
-        )
+        scan_upstream_sub = group_chunks(scan_upstream, packages,
+                                         settings.TASKS_UPSTREAM_GROUPS,
+                                         purge_versions=True)
     else:
-        group(tasks)()
+        scan_upstream_sub = scan_upstream.si(purge_versions=True)
 
+    (
+        scan_upstream_sub |
+        update_counters.si(fast=False)
+    )()
+    return True
 
 @task
-def scan_package_task(package):
-    _scan_portage_task([package], purge_packages=True, purge_versions=True)
-    _scan_metadata_task([package])
-    _scan_upstream_task([package])
+def scan_package(package):
+    scan_portage([package], purge_packages=True, purge_versions=True)
+    scan_metadata([package])
+    scan_upstream([package])
+    return True
 
-
-# Periodic tasks
+@task(rate_limit="1/m")
+def scan_package_user(package):
+    scan_package(package)
+    return True
 
 @task
 def consume_refresh_package_request():
@@ -257,25 +183,39 @@ def consume_refresh_package_request():
     Satisfies user requests for package refreshing, runs every minute
     """
     try:
-        obj = RefreshPackageQuery.objects.all().order_by('-priority')[0]
+        query = RefreshPackageQuery.objects.all().order_by('-priority')[0]
     except IndexError:
-        return {}
-    else:
-        result = scan_package_task(obj.package)
-        obj.delete()
-        return result
+        return
 
+    pkg = query.package
+    query.delete()
+    scan_package_user.delay(pkg)
 
 admin_tasks = [
-    regen_rrds_task,
-    update_counters_task,
-    scan_metadata_list_task,
-    scan_metadata_all_task,
-    scan_portage_all_task,
-    scan_portage_list_task,
-    scan_upstream_all_task,
-    scan_upstream_list_task,
-    update_portage_trees_task,
-    update_task,
-    scan_package_task,
+    regen_rrds,
+    update_counters,
+    scan_metadata,
+    scan_portage,
+    scan_upstream,
+    update_portage_trees,
+    update_portage,
+    update_upstream,
+    scan_package,
 ]
+
+""" Chunk helpers (chunks can't use keyword arguments) """
+@task
+def scan_metadata_category(category):
+    """
+    Helper for calling scan_metadata with a category
+    """
+    scan_metadata(category=category)
+    return True
+
+@task
+def scan_upstream_purge(*packages):
+    """
+    Helper for calling scan_upstream with purge_versions=True
+    """
+    scan_upstream(packages, purge_versions=True)
+    return True
diff --git a/euscanwww/djeuscan/templates/euscan/_categories_table.html b/euscanwww/djeuscan/templates/euscan/_categories_table.html
index cd4ad30..891826f 100644
--- a/euscanwww/djeuscan/templates/euscan/_categories_table.html
+++ b/euscanwww/djeuscan/templates/euscan/_categories_table.html
@@ -1,5 +1,5 @@
 {% load url from future %}
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 
 <table id="table" class="display">
   <thead>
diff --git a/euscanwww/djeuscan/templates/euscan/_herds_table.html b/euscanwww/djeuscan/templates/euscan/_herds_table.html
index 622c9de..f7e5b54 100644
--- a/euscanwww/djeuscan/templates/euscan/_herds_table.html
+++ b/euscanwww/djeuscan/templates/euscan/_herds_table.html
@@ -1,5 +1,5 @@
 {% load url from future %}
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 
 <table id="table" class="display">
   <thead>
diff --git a/euscanwww/djeuscan/templates/euscan/_maintainers_table.html b/euscanwww/djeuscan/templates/euscan/_maintainers_table.html
index ffbd536..ebd1748 100644
--- a/euscanwww/djeuscan/templates/euscan/_maintainers_table.html
+++ b/euscanwww/djeuscan/templates/euscan/_maintainers_table.html
@@ -1,5 +1,5 @@
 {% load url from future %}
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 
 <table id="table" class="display">
   <thead>
diff --git a/euscanwww/djeuscan/templates/euscan/_package_cols.html b/euscanwww/djeuscan/templates/euscan/_package_cols.html
index 20995ce..540a8c1 100644
--- a/euscanwww/djeuscan/templates/euscan/_package_cols.html
+++ b/euscanwww/djeuscan/templates/euscan/_package_cols.html
@@ -1,4 +1,4 @@
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load mul %}
 {% load sub %}
 {% load div %}
diff --git a/euscanwww/djeuscan/templates/euscan/_packages.html b/euscanwww/djeuscan/templates/euscan/_packages.html
index 0ccfdb0..f14072b 100644
--- a/euscanwww/djeuscan/templates/euscan/_packages.html
+++ b/euscanwww/djeuscan/templates/euscan/_packages.html
@@ -1,8 +1,8 @@
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load sub %}
 {% load div %}
 {% load mul %}
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 
 {% load url from future %}
 
diff --git a/euscanwww/djeuscan/templates/euscan/accounts/categories.html b/euscanwww/djeuscan/templates/euscan/accounts/categories.html
index 3b1b6d4..0caa1a6 100644
--- a/euscanwww/djeuscan/templates/euscan/accounts/categories.html
+++ b/euscanwww/djeuscan/templates/euscan/accounts/categories.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 {% load url from future %}
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 
 {% block title %}
   {{ block.super }} - Watched categories
diff --git a/euscanwww/djeuscan/templates/euscan/accounts/herds.html b/euscanwww/djeuscan/templates/euscan/accounts/herds.html
index f34d364..b9d3f50 100644
--- a/euscanwww/djeuscan/templates/euscan/accounts/herds.html
+++ b/euscanwww/djeuscan/templates/euscan/accounts/herds.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 {% load url from future %}
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 
 {% block title %}
   {{ block.super }} - Watched herds
diff --git a/euscanwww/djeuscan/templates/euscan/accounts/maintainers.html b/euscanwww/djeuscan/templates/euscan/accounts/maintainers.html
index 8bce022..cc8eefe 100644
--- a/euscanwww/djeuscan/templates/euscan/accounts/maintainers.html
+++ b/euscanwww/djeuscan/templates/euscan/accounts/maintainers.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 {% load url from future %}
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 
 {% block title %}
   {{ block.super }} - Watched maintainers
diff --git a/euscanwww/djeuscan/templates/euscan/accounts/overlays.html b/euscanwww/djeuscan/templates/euscan/accounts/overlays.html
index 56dacad..946b61e 100644
--- a/euscanwww/djeuscan/templates/euscan/accounts/overlays.html
+++ b/euscanwww/djeuscan/templates/euscan/accounts/overlays.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load url from future %}
 
 {% block title %}
diff --git a/euscanwww/djeuscan/templates/euscan/accounts/packages.html b/euscanwww/djeuscan/templates/euscan/accounts/packages.html
index c83d6cd..46e674b 100644
--- a/euscanwww/djeuscan/templates/euscan/accounts/packages.html
+++ b/euscanwww/djeuscan/templates/euscan/accounts/packages.html
@@ -1,7 +1,7 @@
 {% extends "euscan/_datatable.html" %}
 {% load url from future %}
 
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 
 {% block title %}
   {{ block.super }} - Watched packages
diff --git a/euscanwww/djeuscan/templates/euscan/categories.html b/euscanwww/djeuscan/templates/euscan/categories.html
index 8893b65..93a81f6 100644
--- a/euscanwww/djeuscan/templates/euscan/categories.html
+++ b/euscanwww/djeuscan/templates/euscan/categories.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load url from future %}
 
 {% block title %}
diff --git a/euscanwww/djeuscan/templates/euscan/category.html b/euscanwww/djeuscan/templates/euscan/category.html
index 1f65253..f4f123c 100644
--- a/euscanwww/djeuscan/templates/euscan/category.html
+++ b/euscanwww/djeuscan/templates/euscan/category.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load url from future %}
 
 {% block title %}
diff --git a/euscanwww/djeuscan/templates/euscan/herd.html b/euscanwww/djeuscan/templates/euscan/herd.html
index 9156d39..c940556 100644
--- a/euscanwww/djeuscan/templates/euscan/herd.html
+++ b/euscanwww/djeuscan/templates/euscan/herd.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load url from future %}
 
 {% block title %}
diff --git a/euscanwww/djeuscan/templates/euscan/herds.html b/euscanwww/djeuscan/templates/euscan/herds.html
index 638010f..ff04497 100644
--- a/euscanwww/djeuscan/templates/euscan/herds.html
+++ b/euscanwww/djeuscan/templates/euscan/herds.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load url from future %}
 
 {% block title %}
diff --git a/euscanwww/djeuscan/templates/euscan/maintainer.html b/euscanwww/djeuscan/templates/euscan/maintainer.html
index 828f6b8..a68f987 100644
--- a/euscanwww/djeuscan/templates/euscan/maintainer.html
+++ b/euscanwww/djeuscan/templates/euscan/maintainer.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load url from future %}
 
 {% block title %}
diff --git a/euscanwww/djeuscan/templates/euscan/maintainers.html b/euscanwww/djeuscan/templates/euscan/maintainers.html
index 0c89c04..1514231 100644
--- a/euscanwww/djeuscan/templates/euscan/maintainers.html
+++ b/euscanwww/djeuscan/templates/euscan/maintainers.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load url from future %}
 
 {% block title %}
diff --git a/euscanwww/djeuscan/templates/euscan/overlay.html b/euscanwww/djeuscan/templates/euscan/overlay.html
index 3de2687..21e6a3c 100644
--- a/euscanwww/djeuscan/templates/euscan/overlay.html
+++ b/euscanwww/djeuscan/templates/euscan/overlay.html
@@ -1,7 +1,7 @@
 {% extends "euscan/_datatable.html" %}
 
 {% load url from future %}
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 
 {% block title %}
 {{ block.super }} - Overlay: {{ overlay }}
diff --git a/euscanwww/djeuscan/templates/euscan/overlays.html b/euscanwww/djeuscan/templates/euscan/overlays.html
index 2fc8d4c..8bdafe4 100644
--- a/euscanwww/djeuscan/templates/euscan/overlays.html
+++ b/euscanwww/djeuscan/templates/euscan/overlays.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load url from future %}
 
 {% block title %}
diff --git a/euscanwww/djeuscan/templates/euscan/package.html b/euscanwww/djeuscan/templates/euscan/package.html
index 2f92163..97d1b55 100644
--- a/euscanwww/djeuscan/templates/euscan/package.html
+++ b/euscanwww/djeuscan/templates/euscan/package.html
@@ -1,7 +1,7 @@
 {% extends "euscan/_datatable.html" %}
 
 {% load sub %}
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 {% load url from future %}
 
 {% block meta %}
diff --git a/euscanwww/djeuscan/templates/euscan/world_scan.html b/euscanwww/djeuscan/templates/euscan/world_scan.html
index 11ac23f..ca96488 100644
--- a/euscanwww/djeuscan/templates/euscan/world_scan.html
+++ b/euscanwww/djeuscan/templates/euscan/world_scan.html
@@ -1,6 +1,6 @@
 {% extends "euscan/_datatable.html" %}
 
-{% load euscan_tags %}
+{% load djeuscan_helpers %}
 
 {% block title %}
 {{ block.super }} - World Scan
diff --git a/euscanwww/djeuscan/templatetags/euscan_tags.py b/euscanwww/djeuscan/templatetags/djeuscan_helpers.py
similarity index 90%
rename from euscanwww/djeuscan/templatetags/euscan_tags.py
rename to euscanwww/djeuscan/templatetags/djeuscan_helpers.py
index 625ebb8..9689163 100644
--- a/euscanwww/djeuscan/templatetags/euscan_tags.py
+++ b/euscanwww/djeuscan/templatetags/djeuscan_helpers.py
@@ -1,11 +1,10 @@
 from django import template
 from django.conf import settings
 
-from euscan import helpers
+from euscan.version import is_version_type_stable, get_version_type
 
 register = template.Library()
 
-
 @register.inclusion_tag('euscan/_packages.html', takes_context=True)
 def packages(context, pkgs):
     context['packages'] = pkgs
@@ -61,9 +60,9 @@ def overlays_table(overlays):
 
 @register.filter
 def is_stable(version_type):
-    return helpers.is_version_type_stable(version_type)
+    return is_version_type_stable(version_type)
 
 
 @register.filter
 def version_type(version):
-    return helpers.get_version_type(version)
+    return get_version_type(version)
diff --git a/euscanwww/djeuscan/utils.py b/euscanwww/djeuscan/utils.py
new file mode 100644
index 0000000..19fa00d
--- /dev/null
+++ b/euscanwww/djeuscan/utils.py
@@ -0,0 +1,22 @@
+
+def queryset_iterator(queryset, chunksize=1000):
+        '''''
+        Iterate over a Django Queryset ordered by the primary key
+
+        This method loads a maximum of chunksize (default: 1000) rows in it's
+        memory at the same time while django normally would load all rows in it's
+        memory. Using the iterator() method only causes it to not preload all the
+        classes.
+
+        Note that the implementation of the iterator does not support ordered query sets.
+        '''
+        import gc
+
+        pk = 0
+        last_pk = queryset.order_by('-pk')[0].pk
+        queryset = queryset.order_by('pk')
+        while pk < last_pk:
+            for row in queryset.filter(pk__gt=pk)[:chunksize]:
+                pk = row.pk
+                yield row
+            gc.collect()
diff --git a/euscanwww/euscanwww/settings.py b/euscanwww/euscanwww/settings.py
index 7a936eb..2397c10 100644
--- a/euscanwww/euscanwww/settings.py
+++ b/euscanwww/euscanwww/settings.py
@@ -159,7 +159,6 @@ TEMPLATE_CONTEXT_PROCESSORS = (
 INSTALLED_APPS = (
     'euscanwww',
     'djeuscan',
-
     'django.contrib.auth',
     'django.contrib.contenttypes',
     'django.contrib.sessions',
@@ -237,10 +236,10 @@ CELERY_RESULT_BACKEND = "amqp"
 BROKER_CONNECTION_TIMEOUT = 3600
 CELERYD_CONCURRENCY = 4
 
-TASKS_CONCURRENTLY = 8
-TASKS_SUBTASK_PACKAGES = 32
+TASKS_UPSTREAM_GROUPS = 32
 
 CELERYBEAT_SCHEDULER = "djcelery.schedulers.DatabaseScheduler"
+CELERYBEAT_SCHEDULE = {}
 
 # LDAP authentication
 # TODO: Test data - change me!
diff --git a/pym/euscan/__init__.py b/pym/euscan/__init__.py
index 53d51f6..8efdce4 100644
--- a/pym/euscan/__init__.py
+++ b/pym/euscan/__init__.py
@@ -24,6 +24,7 @@ CONFIG = {
     'mirror': False,
     'ignore-pre-release': False,
     'ignore-pre-release-if-stable': False,
+    'ebuild-uri': False,
 }
 
 BLACKLIST_VERSIONS = [
diff --git a/pym/euscan/helpers.py b/pym/euscan/helpers.py
index 17df9f4..1e385cd 100644
--- a/pym/euscan/helpers.py
+++ b/pym/euscan/helpers.py
@@ -33,27 +33,6 @@ VERSION_CMP_PACKAGE_QUIRKS = {
 _v_end = '((-|_)(pre|p|beta|b|alpha|a|rc|r)\d*)'
 _v = r'((\d+)((\.\d+)*)([a-zA-Z]*?)(' + _v_end + '*))'
 
-
-def is_version_stable(version):
-    return is_version_type_stable(get_version_type(version))
-
-
-def is_version_type_stable(version_type):
-    return version_type not in ("alpha", "beta", "pre", "rc")
-
-
-def get_version_type(version):
-    types = []
-    gentoo_types = ("alpha", "beta", "pre", "rc", "p")
-
-    for token in re.findall("[\._-]([a-zA-Z]+)", version):
-        if token in gentoo_types:
-            types.append(token)
-    if types:
-        return types[0]  # TODO: consider returning all types
-    return "release"
-
-
 # Stolen from g-pypi
 def gentoo_mangle_version(up_pv):
     """Convert PV to MY_PV if needed
@@ -416,7 +395,7 @@ def urlallowed(url):
 
         setdefaulttimeout(timeout)
 
-    return rp.can_fetch(CONFIG['user-agent'], url) if rp else False
+    return rp.can_fetch(CONFIG['user-agent'], url) if rp else True
 
 
 def urlopen(url, timeout=None, verb="GET"):
diff --git a/pym/euscan/out.py b/pym/euscan/out.py
index 4a68982..40374ab 100644
--- a/pym/euscan/out.py
+++ b/pym/euscan/out.py
@@ -5,10 +5,9 @@ import signal
 import time
 import re
 
-from gentoolkit import pprinter as pp
 import portage
 from portage.output import EOutput, TermProgressBar
-
+from gentoolkit import pprinter as pp
 
 class ProgressHandler(object):
     def __init__(self, progress_bar):
@@ -66,6 +65,31 @@ def clean_colors(string):
     return string
 
 
+def transform_url(config, cpv, url):
+    if config['mirror']:
+        url = to_mirror(url)
+    if config['ebuild-uri']:
+        url = to_ebuild_uri(cpv, url)
+    return url
+
+def to_ebuild_uri(cpv, url):
+    cat, pkg, ver, rev = portage.catpkgsplit(cpv)
+    p = '%s-%s' % (pkg, ver)
+    pvr = '%s%s' % (ver, '-%s' % rev if rev != 'r0' else '')
+    pf = '%s-%s' % (pkg, pvr)
+    evars = (
+        (p  , 'P'),
+        (pkg, 'PN'),
+        (ver, 'PV'),
+        (rev, 'PR'),
+        (pvr, 'PVR'),
+        (pf , 'PF'),
+        (cat, 'CATEGORY')
+    )
+    for src, dst in evars:
+        url = url.replace(src, '${%s}' % dst)
+    return url
+
 def to_mirror(url):
     mirrors = portage.settings.thirdpartymirrors()
     for mirror_name in mirrors:
@@ -146,15 +170,17 @@ class EuscanOutput(object):
             raise TypeError("Invalid output format")
 
     def result(self, cp, version, urls, handler, confidence):
-        from euscan.helpers import get_version_type
+        from euscan.version import get_version_type
 
-        if self.config['format']:
+        cpv = '%s-%s' % (cp, version)
+        urls = ' '.join(transform_url(self.config, cpv, url) for url in urls.split())
+
+        if self.config['format'] in ['json']:
             _curr = self.queries[self.current_query]
             _curr["result"].append(
                 {
                     "version": version,
-                    "urls": [to_mirror(url) if self.config['mirror'] else url
-                             for url in urls.split()],
+                    "urls": urls.split(),
                     "handler": handler,
                     "confidence": confidence,
                     "type": get_version_type(version)
diff --git a/pym/euscan/scan.py b/pym/euscan/scan.py
index ded800a..d63488b 100644
--- a/pym/euscan/scan.py
+++ b/pym/euscan/scan.py
@@ -13,7 +13,8 @@ from gentoolkit.package import Package
 
 from euscan import CONFIG, BLACKLIST_PACKAGES
 from euscan import handlers, output
-from euscan.helpers import version_blacklisted, is_version_stable
+from euscan.helpers import version_blacklisted
+from euscan.version import is_version_stable
 from euscan.ebuild import package_from_ebuild
 
 
diff --git a/pym/euscan/version.py b/pym/euscan/version.py
index d836c7e..b2ebdfe 100644
--- a/pym/euscan/version.py
+++ b/pym/euscan/version.py
@@ -1,5 +1,22 @@
 import re
 
+def is_version_type_stable(version_type):
+    return version_type not in ("alpha", "beta", "pre", "rc")
+
+def is_version_stable(version):
+    return is_version_type_stable(get_version_type(version))
+
+def get_version_type(version):
+    types = []
+    gentoo_types = ("alpha", "beta", "pre", "rc", "p")
+
+    for token in re.findall("[\._-]([a-zA-Z]+)", version):
+        if token in gentoo_types:
+            types.append(token)
+    if types:
+        return types[0]  # TODO: consider returning all types
+    return "release"
+
 # Stolen from pkg_resources, but importing it is not a good idea
 
 component_re = re.compile(r'(\d+ | [a-z]+ | \.| -)', re.VERBOSE)