This chapter provides information about how to configure an
external database to store information synchronized from
the Cisco Unified Communications Manager IM and Presence Service. The following
IM and Presence features require
an external database:
Permanent Group Chat feature -
IM and Presence supports two
types of group chat, temporary (ad-hoc) chat and permanent chat. You do not
require an external database for temporary chat to work. However, if you
require permanent chat rooms on
IM and Presence, you must
configure an external database.
Instant Messaging Compliance - If you deploy the native Message
Archiver (MA) component on IM and Presence for compliance logging, you
require an external database.
Hardware requirements:
A remote server on which you install the PostgreSQL database(s).
Software requirements:
IM and Presence Service,
release 9.0.
PostgreSQL database, versions 8.3.x through 9.1.1
You can install the PostgreSQL database on either a Linux or a
Windows operating system. See the PostgreSQL documentation for details on the
supported operating systems and platform requirements.
Note
You can also use version 8.1.x of the PostgreSQL database, but the
configuration of these versions may be different to the PostgreSQL database
configuration described in this module. See the PostgreSQL documentation for
details on how to configure these PostgreSQL database versions. If you use
version 8.1.x of the PostgreSQL database, the database configuration on IM and Presence will be the
same as described in this module.
External Database requirements for
IM and Presence features:
The external database requirements differ depending on the
features you wish to deploy on
IM and Presence:
Permanent Group Chat feature: You require one unique external
database for each
IM and Presence server
in an
IM and Presence cluster.
Each node requires its own logical database, but nodes can share the same
physical database installation.
Compliance feature: We highly recommend that you configure at
least one external database for an
IM and Presence cluster;
however you may require more than one external database for a cluster depending
on your server capacity.
Note
If you deploy both the Permanent Group Chat and Compliance features
on an
IM and Presence server you
can assign the same external database to both features.
This procedure only describes how to configure the external
database on
IM and Presence. It does not
describe how to fully configure the features that require the external
database, specifically the Permanent Group Chat and Compliance features. See
the documentation specific to the feature you are deploying for the complete
configuration:
For information on configuring the Compliance feature on
IM and Presence, see the
Instant Messaging Compliance for IM and Presence Service on Cisco Unified Communications Manager
For information on configuring the Permanent Group Chat feature on
IM and Presence, see the
Deployment Guide for IM and Presence Service on Cisco Unified
Communications Manager
External database setup prerequisites
Before you install and configure the external database on
IM and Presence, perform the
following tasks:
Install the
IM and Presence servers as
described in the
Installing Cisco Unified Communications Manager.
Configure the
IM and Presence servers as
described in the
Deployment Guide for IM and Presence Service on Cisco Unified
Communications Manager.
Hardware and performance recommendations
When you configure an external database with IM and Presence, you need to
consider the following recommendations:
We recommend that you use similar hardware for both the external
database and the
IM and Presence nodes.
We recommend that you maintain the external database according to
the best practice guidelines described in the product documentation. If you do
not properly maintain the external database, and you allow the external
database to fill up, this causes performance problems in the
IM and Presence cluster.
IM and Presence does not provide a secure TLS/SSL connection to the external database. We recommend that you consider this security limitation when you plan your IM and Presence deployment, and consider the security recommendations we provide in this topic.
User access restriction recommendations
We strongly recommend that you restrict user access to the
external database to only the particular user and database instance that
IM and Presence uses. You can
restrict user access to the PostgreSQL database in the pg_hba.conf file located
in the <install_dir>/data directory.
Caution
Do not configure 'all' for the user and database entries because
potentially this could allow any user access to any database.
When you configure user access to the external database, we
also recommend that you configure password protection for the database access
using the 'password' method.
Note
You are required to enter a password for the database user when you
configure a database entry on IM and Presence.
The following are examples of a secure user access
configuration, and a less secure user access configuration, in the pg_hba.conf
file.
Example of a secure configuration:
# TYPE
DATABASE
USER
CIDR-ADDRESS
METHOD
host
dbinst1
tcuser1
10.89.99.0/24
password
host
dbinst2
mauser1
10.89.99.0/24
password
Example of a less secure configuration:
# TYPE
DATABASE
USER
CIDR-ADDRESS
METHOD
host
dbinst1
tcuser1
10.89.99.0/24
trust
host
dbinst2
all
10.89.99.0/24
password
Notes on the example of a less secure configuration:
The first entry contains no password protection for the database.
The second entry allows any user to access the database
"dbinst2".
Use this section as a guideline if you wish to limit the number of
connections to the database. This section is optional configuration.
For additional security, you can limit the maximum number of
permitted connections to the external database. Use the guideline we provide
here to calculate the number of database connections that are appropriate for
your deployment.
You must modify this guideline to suit your
IM and Presence deployment and
configuration. The guideline we provide here assumes that:
You are running both the Compliance and Permanent Group Chat
features on
IM and Presence.
and
You configure the default number of connections to the database
for the Permanent Group Chat feature on
IM and Presence
administration interface.
To limit the number of database connections, configure the
max_connections value in the postgresql.conf file located in the
<install_dir>/data directory. We recommend that you set the value of the
max_connections parameter equal to this guideline:
max_connections = N*10 + Additional Connections
N is the number of nodes in your
IM and Presence cluster.
10 is the default number of connections to the database on
IM and Presence, that is,
five connections for the Compliance feature and five connections for the
Permanent Group Chat feature. You can configure the number of database
connections for the Permanent Group Chat feature on
IM and Presence
Administration interface.
Additional Connections represents any independent administration
or database administrator (DBA) connections to the database server.
For example, if you have an
IM and Presence cluster
containing six nodes, and you require an additional three DBA connections,
using the guideline above, you should set the max_connections value to 63.
For additional security, you may choose to change the
default listening port on the PostgreSQL server. You can configure the default
listening port in the postgresql.conf file located in the
<install_dir>/data directory.