Distributed time services

Synchronizing clocks across a network or group of networks helps programs that use time stamps function accurately. Examples include database, configuration management, and transaction-processing programs. Without this synchronization, database files may be simultaneously (and incorrectly) accessed by multiple machines, or updates to system files may be pushed to remote machines at incorrect times.

Use the Time Synchronization Protocol (TSP) or the Network Time Protocol (NTP), both members of the TCP/IP protocol suite, to synchronize clocks on your network.

Both TSP and NTP are fully supported. Each has its own advantages, which are fully detailed in ``TSP guidelines'' and ``NTP guidelines''. The primary differences between NTP and TSP are:

• NTP synchronizes clocks to Coordinated Universal Time (UTC), the international time standard. TSP synchronizes clocks to a master time server you designate, which may or may not be synchronized to an external standard.

• A set of NTP servers, located on and accessible via the Internet, provide NTP services to machines with Internet access. TSP servers and clients must be configured on the local network.

  ---

  NOTE: It is possible to use NTP without Internet access but with diminished accuracy. It is also possible to configure a TSP server that is itself an NTP client.

  ---

• TSP consists of a single server (that you define) servicing a group of clients. If the server goes down, an election algorithm determines a new server, which then takes over responsibility for time synchronization. With NTP, a hierarchy of servers, some on the local network, some on the Internet, handle time synchronization. This redundancy of servers allows one or more to go down without jeopardizing time synchronization on the local network.

• TSP is fairly straightforward to configure and administer, while NTP offers more functional robustness and has a more complex underlying file structure.