Calendar Server services run as daemons (or processes). These services include:
The csadmind service manages alarm notifications, and group scheduling requests.
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
When properly configured, the csstored service creates automatic backups of the calendar database. 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 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 9, 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 22.5.4 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 22.5.8 Restoring an Automatic Backup Copy.
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 the subscriber. The default subscriber for the Calendar Server system is csnotifyd.
The enpd and csnotifyd services are not required to run on the same server as the cshttpd, csdwpd, or csadmind processes.
Using csdwpd, you can create a distributed calendar store. That is, use csdwpd to manage calendar databases spread across multiple back-end servers within the same Calendar Server configuration.
The csdwpd service runs in the background on back-end servers 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.