Merge "Allows to use cradox with ceph storage"

devstack/plugin.sh

@@ -319,6 +319,10 @@ function preinstall_gnocchi {
     else
         install_package postgresql-devel
     fi
+    if [[ "$GNOCCHI_STORAGE_BACKEND" = 'ceph' ]] ; then
+            install_package cython
+            install_package librados-dev
+    fi
 }
 
 # install_gnocchi() - Collect source and prepare
@@ -332,6 +336,10 @@ function install_gnocchi {
         pip_install influxdb
     fi
 
+    if [[ "$GNOCCHI_STORAGE_BACKEND" = 'ceph' ]] ; then
+        pip_install cradox
+    fi
+
     if is_service_enabled gnocchi-grafana
     then
         _gnocchi_install_grafana

devstack/settings

@@ -36,7 +36,7 @@ GNOCCHI_STATSD_RESOURCE_ID=${GNOCCHI_STATSD_RESOURCE_ID:-$(uuidgen)}
 GNOCCHI_STATSD_USER_ID=${GNOCCHI_STATSD_USER_ID:-$(uuidgen)}
 GNOCCHI_STATSD_PROJECT_ID=${GNOCCHI_STATSD_PROJECT_ID:-$(uuidgen)}
 
-# ceph gnochi info
+# ceph gnocchi info
 GNOCCHI_CEPH_USER=${GNOCCHI_CEPH_USER:-gnocchi}
 GNOCCHI_CEPH_POOL=${GNOCCHI_CEPH_POOL:-gnocchi}
 GNOCCHI_CEPH_POOL_PG=${GNOCCHI_CEPH_POOL_PG:-8}

doc/source/configuration.rst

@@ -167,4 +167,21 @@ result from:
 So, in realistic scenarios, the direct relation between the archive policy and
 the size of the rados objects created by Gnocchi is not a problem.
 
+
+Also Gnocchi can use `cradox`_ Python libary if installed. This library is a
+Python binding to librados written with `Cython`_, aiming to replace the one
+written with `ctypes`_ provided by Ceph.
+This new library will be part of next Ceph release (10.0.4).
+
+The new Cython binding divides the gnocchi-metricd times to process measures
+by a large factor.
+
+So, if the Ceph installation doesn't use latest Ceph version, `cradox`_ can be
+installed to improve the Ceph backend performance.
+
+
 .. _`Ceph extended attributes documentation`: http://docs.ceph.com/docs/master/rados/configuration/filestore-config-ref/#extended-attributes
+.. _`cradox`: https://pypi.python.org/pypi/cradox
+.. _`Cython`: http://cython.org/
+.. _`ctypes`: https://docs.python.org/2/library/ctypes.html
+.. _`rados.py`: https://docs.python.org/2/library/ctypes.htm://github.com/ceph/ceph/blob/hammer/src/pybind/rados.py

gnocchi/storage/ceph.py

@@ -29,8 +29,13 @@ from gnocchi.storage import _carbonara
 
 LOG = logging.getLogger(__name__)
 
-# NOTE(sileht): rados module is not available on pypi
-rados = importutils.try_import('rados')
+for RADOS_MODULE_NAME in ('cradox', 'rados'):
+    rados = importutils.try_import(RADOS_MODULE_NAME)
+    if rados is not None:
+        break
+else:
+    RADOS_MODULE_NAME = None
+
 if rados is not None and hasattr(rados, 'run_in_thread'):
     rados.run_in_thread = lambda target, args, timeout=None: target(*args)
     LOG.info("rados.run_in_thread is monkeypatched.")
@@ -59,6 +64,12 @@ class CephStorage(_carbonara.CarbonaraBasedStorage):
         if conf.ceph_keyring:
             options['keyring'] = conf.ceph_keyring
 
+        if not rados:
+            raise ImportError("No module named 'rados' nor 'cradox'")
+
+        LOG.info("Ceph storage backend use '%s' python library" %
+                 RADOS_MODULE_NAME)
+
         # NOTE(sileht): librados handles reconnection itself,
         # by default if a call timeout (30sec), it raises
         # a rados.Timeout exception, and librados