Journaling - ModeShape 5

Overview

ModeShape offers the ability to store for each repository a local journal of all the events that occurred within the repository.

The journal itself is not exposed to clients directly, but needs to be enabled in order to support other features like:

JCR Journaled Observation
rebuilding indexes from a point in time

Configuration

In order to enable journaling you need to at least define a location for it in the JSON configuration:

"journaling" : {
        "location" : "target/journal"
}

There are several other attributes which can be configured as well:

Attribute name	Default value	Description
`location`		A mandatory attribute representing the location on the file system where the data should be stored
`maxDaysToKeepRecords`	-1	The number of days to keep records. By default -1, meaning records will be kept indefinitely. In large system however, this may be impractical as it may cause the jornal to grow significantly in size.
`threadPool`	`modeshape-journaling-gc`	The name of the repository thread which will cleanup older journal entries. Only used if `maxDaysToKeepRecords` is not -1.
`initialTime`	`00:00`	The local time (hours:minutes) at which the cleanup thread should be run. Only used if `maxDaysToKeepRecords` is not -1.
`intervalInHours`	`24`	The interval (in hours) at which the cleanup thread should be run. Only used if `maxDaysToKeepRecords` is not -1.
`asyncWritesEnabled`	`false`	Whether writes to the journal should be asynchronous or not.
`enabled`	`true`	Whether the journal is active or not

A fully configured journal would look similar to:

 "journaling" : {
        "location" : "target/journal",
        "maxDaysToKeepRecords" : 15,
        "asyncWritesEnabled" : false,
        "threadPool" : "modeshape-journaling-gc",
        "initialTime" : "04:01",
        "intervalInHours" : 5,
        "enabled" : true
    }

The journaling functionality is also integrated, configuration wise, into the WildFly subsystem. To enable it, one has to at least configure it like so:

<journaling/>

By default, the location of the records is: jboss.server.data.dir/modeshape/repositoryName/journal.

A fully configured journal would have the same attributes from above:

<journaling max-days-to-keep-records="" async-writes="" journal-path="" journal-relative-to="" journal-gc-initial-time="" journal-gc-thread-pool="" enabled="true"/>