Calendar Server Services

Calendar Server services run as daemons (or processes). These services include:

• Administration Service: csadmind

• HTTP Service: cshttpd

• Automatic Backup Service: csstored

• Event Notification Service (ENS): csnotifyd and enpd

• Distributed Database Service: csdwpd

Administration Service: csadmind

The csadmind service provides a single point of authentication for administering Calendar Server. The csadmind service also manages alarm notifications, group scheduling requests.

HTTP Service: cshttpd

Since Calendar Server uses HTTP as its primary transport, the cshttpd service listens for HTTP commands from Calendar Server end users, receives the user commands, and returns calendar data, depending on the format specified in the incoming WCAP command. Data can be formatted in standard RFC 2445 iCalendar format (text/calendar) or XML format (text/xml

Automatic Backup Service: csstored

When properly configured, the csstored service creates automatic backups of the calendar database. However, the service is installed in an unconfigured state. You can configure Calendar Server for automatic backups when the csconfigurator.sh configuration program runs, or you can do it at a later time, as described in this guide.

If the service is started in the unconfigured and disabled state, it will send a message to the administrator every 24 hours stating that automatic backups are not enabled.

For instructions on how to configure this service to perform backups, see Chapter 10, Configuring Automatic Backups (csstored).

When configured properly, the service has the following functionality:

• Upon system start up and at 24 hour (default interval) intervals thereafter, takes a snapshot of the live Calendar Server calendar database. The interval is configurable. (If the service has been stopped and restarted, it does not take another snapshot unless the configured interval has elapsed since the last snapshot.)

• Verifies the database by running csdb verify against the backup copy.

  If the verify step fails (the database is corrupted), the service notifies the administrator. The administrator can put the live database in read-only mode, allowing you to troubleshoot the problem without having to shut down the databases. While in read-only mode, no modify or delete transactions are accepted (no logging). For more information about read-only mode, see Preventing Service Interruptions When Your Database is Corrupted (Read-only Mode).

  Administrator intervention is required when a corruption is sensed. A notification is sent to the administrator.

  If the verify succeeds, csstored performs the following additional tasks:

• Creates an archival backup consisting of the database snapshot and all the transaction log files that were applied to it since the previous snapshot.

• Creates a hot backup consisting of the database snapshot with the transaction log files applied to it.

  Should the live database become corrupted, a hot backup provides an immediate up to date backup of the database with a minimum of data loss and downtime.

  For information on how to restore an automatic backup copy, see Restoring an Automatic Backup Copy.

Event Notification Service (ENS): csnotifyd and enpd

The ENS service consists of these individual services:

• csnotifyd–The csnotifyd service sends notifications of events and todos (tasks). The csnotifyd service also subscribes to alarm events. When an alarm event occurs, csnotifyd sends an SMTP message reminder to each recipient.

• enpd–The enpd service acts as the broker for event alarms. The enpd service receives notifications of alarms from the csadmind service, checks for subscriptions to this event, and then notifies the event’s subscribers by passing the subscribed-to alarm notifications to csnotifyd. The enpd service also receives and stores subscriptions and cancellations of subscriptions (unsubscribe) from csnotifyd.

The enpd and csnotifyd services are not required to run on the same server as the cshttpd, csdwpd, or csadmind processes.

Distributed Database Service: csdwpd

The csdwpd service is required to distribute calendar databases across multiple back-end servers. The csdwpd service allows you to spread the calendar database across multiple back-end servers within the same Calendar Server configuration to form a distributed calendar store.

The csdwpd service runs in the background on a back-end server and accepts requests that follow the Database Wire Protocol (DWP) for accessing the calendar database. DWP is an internal protocol used to provide networking capability for the Calendar Server database.