zc.zrs 2.5.2

Configuration with ZConfig

If using an application, like a ZEO server or Zope, that uses ZConfig to configure ZODB storages, the configuration of a ZRS primary or secondary storage may be included in the configuration file as with any other storage e.g, to configure a primary storage, use something like:

%import zc.zrs

<zrs>
 replicate-to 5000

 <filestorage>
     path /path/to/data/file
 </filestorage>
</zrs>

Here is a line-by-line walk through:

%import zc.zrs

The import statement is necessary to load the ZConfig schema definitions for ZRS.

<zrs>

The zrs section defines a ZRS storage. A ZRS storage may be a primary storage or a secondary storage. A ZRS storage without a replicate-from option (as in the example above) is a primary storage.

replicate-to 5000

The replicate-to option specifies the replication address. Secondary storages will connect to this address to download replication data. This address can be a port number or a host name (interface name) and port number separated by a colon.

<filestorage>
  path /path/to/data/file
</filestorage>

A ZRS storage section must include a filestorage section specifying a file storage to contain the data.

Configuring a secondary storage is similar to configuring a primary storage:

%import zc.zrs

<zrs>
 replicate-from primary-host:5000
 replicate-to 5000
 keep-alive-delay 60

 <filestorage>
     path /path/to/secondary/data/file
 </filestorage>
</zrs>

For a secondary storage, a replicate-from option is used to specify the address to replicate data from.

Because primary and secondary storages are generally on separate machines, the host is usually specified in a replicate-from option.

A secondary storage can also specify a replicate-to option. If this option is used, other secondary storages can then replicate from the secondary, rather than replicating from the primary.

Secondary storages also support the following optional option:

keep-alive-delay SECONDS

In some network configurations, TCP connections are broken after extended periods of inactivity. This may even be done in a way that a client doesn’t detect the disconnection. To prevent this, you can use the keep-alive-delay option to cause the secondary storage to send periodic no-operation messages to the server.

2.5.3 2015-02-16

• Fixed: monitor got the primary last transaction time before before getting the secondary last transaction time, sometimes leading to spurious reports of the primary being behind the secondary.

2.5.2 2015-02-07

Fixed: the nagios monitor only worked if the primary and secondary ran

in the same process (as in they did in the tests.)

2.5.1 2015-01-28

Include src/**/*.rst files in sdist.

2.5.0 2015-01-25

Added nagios plugins for monitoring replication.

2.4.4 2013-08-17

Fixed packaging bug: component.xml was left out.

2.4.3 2013-08-15

Packaging update: allow installation without setuptools.

2.4.2 2013-05-27

Initial open-source release for ZODB 3.9 or later.

2.0.5 2013-05-27

Initial open-source release for ZODB 3.8.

Initial open-source release. Requires ZODB 3.9 or later.