Replication
This topic assumes you have read the Guidelines for setting up multi-server services
Replication is the duplication of server data from the master server The innermost Helix Core server in a multi-server topology. A commit server can also be referred to as a master server. to the replica A Helix Core Server that automatically maintains a full or partial copy of the master server's metadata and that might contain related file content. The replica copies from its master by using 'p4 pull' or 'p4 journalcopy'. A replica can be used as a backup server for disaster recovery., ideally in real time. You can use replication to:
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Provide warm standby servers
A replica server can function as an up-to-date warm standby system to be used if the master server fails. Such a replica server requires that both server metadata and versioned files are replicated.
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Reduce load and downtime on a primary server
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Provide support for build farms
A replica with a local (non-replicated) storage for client workspaces (and their respective have lists) is capable of running as a build farm.
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Forward write requests to a central server
A forwarding replica holds a readable cache of both versioned files and metadata, and forwards commands that write metadata or file content towards a central server. A forwarding replica offers a blend of the functionality of the Helix Proxy with the improved performance of a replica. (See Forwarding replica.)
Combined with a centralized authorization server, Helix Core Server administrators can configure the Helix Broker to redirect commands to replica servers to balance load efficiently across an arbitrary number of replica servers. See Centralized authorization server (P4AUTH) and Helix Broker.
Helix Core also supports Failover, which involves replication.
If you require read and write access to a remote server
Most replica configurations are intended for reading of data. If you require read and write access to a remote server, consider using a:
- forwarding replica - Forwarding replica
- multi-server Perforce service - Commit-edge
- the Helix Proxy - Helix Proxy
Additional information
The following provide additional information about replication.
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Perforce Knowledge Base articles:
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A detailed walk-through of Installing a Helix Replica Server
- The use case for a journal prefix at Configuring Checkpoint and Rotated Journal location in Distributed Helix Environments
- A detailed walk-through of Inspecting replication progress
- In case a replica server appears to be corrupted, How to reseed a replica server
- Details about how certain commands behave differently on Edge Servers
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