mod_storage_xmlarchive

Introduction

This module implements stanza archives using files, similar to the default “internal” storage. Unlike “internal”, it saves messages in two files per day (and per user), one containing metadata and one containing the actual messages in XML format (hence the name).

Splitting data per day improves performance for larger archives as it does not have to look through data from other days.

Configuration

To use this with mod_mam add this to your config:

storage = {
    archive = "xmlarchive"
}

To use it with mod_mam_muc or mod_http_muc_log:

storage = {
    muc_log = "xmlarchive"
}

Refer to Prosodys data storage documentation for more information.

Note that this module does not implement the “keyval” storage method and can’t be used by anything other than archives.

Conversion to or from internal storage

This module stores data in a way that overlaps with the more recent archive support in mod_storage_internal, meaning e.g. mod_migrate will not be able to cleanly convert to or from the xmlarchive format.

To mitigate this, an migration command has been added to mod_storage_xmlarchive:

prosodyctl mod_storage_xmlarchive convert $DIR internal $STORE $JID+

Where $DIR is to or from, $STORE is e.g. archive or archive2 for MAM and muc_log for MUC logs. Finally, $JID is one or more JID of the users or MUC rooms to be migrated.

To migrate all users/rooms on a particular host, pass a bare hostname.

Data structure

Data is split in three kinds of files and messages are grouped by day. Prosodys util.datamanager is used, so all special characters in these filenames are escaped and reside under hostname/store in Prosodys Data directory, commonly /var/lib/prosody.

username.list

A list of dates in YYYY-MM-DD format.

username@YYYY-MM-DD.list

Index containing metadata for messages stored on that day.

username@YYYY-MM-DD.xml

Messages in textual XML format, separated by newlines.

This makes it fairly simple and fast to find messages by timestamp. Queries that are not time based, but limited to a specific contact may be expensive as potentially the entire archive will be read.

Each archive ID is of the form YYYY-MM-DD-random, making lookups by archive id just as simple as time based queries.

Limitations

• Only XML stanzas can be stored.
• The deletion method only supports removing entire days at a time.

Compatibility

sudo prosodyctl install --server=https://modules.prosody.im/rocks/ mod_storage_xmlarchive