ejabberd PubSub features

The ejabberd XMPP server offers a very rich PubSub module (mod_pubsub), enabling a wide range of publish and subscribe applications. PubSub is the type of feature used by WordPress to publish updates on blog in near realtime and is a key component of the real time web.

ejabberd has received a lot of improvements in the PubSub module during the version 2.1.0 development process.

First, ejabberd’s PubSub module underwent a partial rewrite to enable optimizations in terms of I/O (input and output) resulting in a lot performance improvements. The PubSub module also now supports ODBC, which enables storage of large volumes of data.

Regarding the performance, this PubSub implementation has been deployed in production on several huge and high profile events distribution platform. We will publish more informations on those use cases soon.

As you can see, although mod_pubsub does not yet cover 100 % of the related specifications (XEP-0060 and XEP-0248), it is quite complete. Many thanks go to Brian Cully, who worked hard to contribute to this module and helped Christophe Romain, lead PubSub developer at ProcessOne.

Here is a summary of the PubSub features that are now implemented in ejabberd:

Features	Implementation	XEP Ref.	XEP link
access-authorize	✔	4.5 Node Access Model	http://xmpp.org/extensions/xep-0060.html#accessmodels
access-open	✔	4.5 Node Access Model	http://xmpp.org/extensions/xep-0060.html#accessmodels
access-presence	✔	4.5 Node Access Model	http://xmpp.org/extensions/xep-0060.html#accessmodels
access-roster	✖	4.5 Node Access Model	http://xmpp.org/extensions/xep-0060.html#accessmodels
access-whitelist	✔	4.5 Node Access Model	http://xmpp.org/extensions/xep-0060.html#accessmodels
auto-create	✔	7.1.4 Automatic Node Creation	http://xmpp.org/extensions/xep-0060.html#publisher-publish-autocreate
auto-subscribe	✔	9.1 Auto-Subscribe	http://xmpp.org/extensions/xep-0060.html#auto-subscribe
collections	✔		http://xmpp.org/extensions/xep-0248.html
config-node	✔	8.2 Configure a Node	http://xmpp.org/extensions/xep-0060.html#owner-configure
create-and-configure	✔	8.1.3 Create and Configure a Node	http://xmpp.org/extensions/xep-0060.html#owner-create-and-configure
create-nodes	✔	8.1 Create a Node	http://xmpp.org/extensions/xep-0060.html#owner-create
delete-items	✔	7.2 Delete an Item from a Node	http://xmpp.org/extensions/xep-0060.html#publisher-delete
delete-nodes	✔	7.2 Delete an Item from a Node	http://xmpp.org/extensions/xep-0060.html#owner-delete
filtered-notifications	✔	9.2 Filtered Notifications	http://xmpp.org/extensions/xep-0060.html#filtered-notifications
get-pending	✔	8.6 Manage Subscription Requests	http://xmpp.org/extensions/xep-0060.html#owner-subreq
instant-nodes	✔	8.1 Create a Node	http://xmpp.org/extensions/xep-0060.html#owner-create
item-ids	✔	N/A	N/A
last-published	✔	6.1.7 Receiving the Last Published Item	http://xmpp.org/extensions/xep-0060.html#subscriber-subscribe-last
leased-subscription	✖	12.18 Time-Based Subscriptions (Leases)	http://xmpp.org/extensions/xep-0060.html#impl-leases
manage-subscription	✔	8.8 Manage Subscriptions	http://xmpp.org/extensions/xep-0060.html#owner-subscriptions
member-affiliation	✔	4.1 Affiliations	http://xmpp.org/extensions/xep-0060.html#affiliations
meta-data	✖	N/A	N/A
modify-affiliations	✔	8.9 Manage Affiliations	http://xmpp.org/extensions/xep-0060.html#owner-affiliations
multi-collection	✔	6.3.1 Only One Collection Node	http://xmpp.org/extensions/xep-0248.html#createassociated-error-onenode
multi-subscribe	✔	6.1.6 Multiple Subscriptions	http://xmpp.org/extensions/xep-0060.html#subscriber-subscribe-multi
outcast-affiliation	✔	4.1 Affiliations	http://xmpp.org/extensions/xep-0060.html#affiliations
persistent-items	✔	N/A	N/A
presence-notifications	✔	N/A	N/A
presence-subscribe	✔	9.1 Auto-Subscribe	http://xmpp.org/extensions/xep-0060.html#auto-subscribe
publish	✔	7.1 Publish an Item to a Node	http://xmpp.org/extensions/xep-0060.html#publisher-publish
publish-options	✖	7.1.5 Publishing Options	http://xmpp.org/extensions/xep-0060.html#publisher-publish-options
publisher-affiliation	✔	4.1 Affiliations	http://xmpp.org/extensions/xep-0060.html#affiliations
purge-nodes	✔	8.5 Purge All Node Items	http://xmpp.org/extensions/xep-0060.html#owner-purge
retract-items	✔	7.2 Delete an Item from a Node	http://xmpp.org/extensions/xep-0060.html#publisher-delete
retrieve-affiliations	✔	5.7 Retrieve Affiliations	http://xmpp.org/extensions/xep-0060.html#entity-affiliations
retrieve-default	✔	8.3 Request Default Configuration Options	http://xmpp.org/extensions/xep-0060.html#owner-default
retrieve-items	✔	6.4 Retrieve Items from a Node	http://xmpp.org/extensions/xep-0060.html#subscriber-retrieve
retrieve-subscriptions	✔	5.6 Retrieve Subscriptions	http://xmpp.org/extensions/xep-0060.html#entity-subscriptions
subscribe	✔	6.1 Subscribe to a Node & 6.2 Unsubscribe from a Node	http://xmpp.org/extensions/xep-0060.html#subscriber-subscribe & http://xmpp.org/extensions/xep-0060.html#subscriber-unsubscribe
subscription-options	✔	6.3 Configure Subscription Options	http://xmpp.org/extensions/xep-0060.html#subscriber-configure
subscription-notifications	✔	12.12 Notification of Subscription State Changes	http://xmpp.org/extensions/xep-0060.html#impl-subchange

Feel free to download and test our latest ejabberd 2.1 RC1, your feedback is encouraged and will be welcome.