diff options
Diffstat (limited to 'src/lib/Bcfg2/Server/Plugins/Metadata.py')
| -rw-r--r-- | src/lib/Bcfg2/Server/Plugins/Metadata.py | 41 |
1 files changed, 36 insertions, 5 deletions
diff --git a/src/lib/Bcfg2/Server/Plugins/Metadata.py b/src/lib/Bcfg2/Server/Plugins/Metadata.py index 6ff256147..bf51ff678 100644 --- a/src/lib/Bcfg2/Server/Plugins/Metadata.py +++ b/src/lib/Bcfg2/Server/Plugins/Metadata.py @@ -686,7 +686,7 @@ class Metadata(Bcfg2.Server.Plugin.Metadata, client = MetadataClientModel(hostname=client_name) # pylint: enable=E1102 client.save() - self.clients = self.list_clients() + self.update_client_list() return client else: try: @@ -739,7 +739,15 @@ class Metadata(Bcfg2.Server.Plugin.Metadata, attribs, alias=True) def list_clients(self): - """ List all clients in client database """ + """ List all clients in client database. + + Making ``self.clients`` a property and reading the client list + dynamically from the database on every call to + ``self.clients`` can result in very high rates of database + reads, so we cache the ``list_clients()`` results to reduce + the database load. When the database is in use, the client + list is reread periodically with + :func:`Bcfg2.Server.Plugins.Metadata.update_client_list`. """ if self._use_db: return set([c.hostname for c in MetadataClientModel.objects.all()]) else: @@ -790,7 +798,7 @@ class Metadata(Bcfg2.Server.Plugin.Metadata, self.logger.warning(msg) raise Bcfg2.Server.Plugin.MetadataConsistencyError(msg) client.delete() - self.clients = self.list_clients() + self.update_client_list() else: return self._remove_xdata(self.clients_xml, "Client", client_name) @@ -859,8 +867,7 @@ class Metadata(Bcfg2.Server.Plugin.Metadata, except KeyError: self.clientgroups[clname] = [profile] self.states['clients.xml'] = True - if self._use_db: - self.clients = self.list_clients() + self.update_client_list() def _get_condition(self, element): """ Return a predicate that returns True if a client meets @@ -1452,6 +1459,30 @@ class Metadata(Bcfg2.Server.Plugin.Metadata, return True # pylint: enable=R0911,R0912 + def update_client_list(self): + """ Re-read the client list from the database (if the database is in + use) """ + if self._use_db: + self.logger.debug("Metadata: Re-reading client list from database") + old = set(self.clients) + self.clients = self.list_clients() + new = set(self.clients) + added = new - old + removed = old - new + self.logger.debug("Metadata: Added %s clients: %s" % + (len(added), added)) + self.logger.debug("Metadata: Removed %s clients: %s" % + (len(removed), removed)) + # we could do this with set.symmetric_difference(), but we + # want detailed numbers of added/removed clients for + # logging + for client in added.union(removed): + self.expire_cache(client) + + def start_client_run(self, metadata): + """ Hook to reread client list if the database is in use """ + self.update_client_list() + def end_statistics(self, metadata): """ Hook to toggle clients in bootstrap mode """ if self.auth.get(metadata.hostname, |