---

labels:

- 'Stage-Beta'

- 'Type-Storage'

- ArchiveStorage

summary: XML file based archive storage

---

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:

``` lua

storage = {

    archive = "xmlarchive"

}

```

To use it with [mod\_mam\_muc] or [mod\_http\_muc\_log]:

``` lua

storage = {

    muc_log = "xmlarchive"

}

```

Refer to [Prosodys data storage documentation][doc:storage] for more

information.

Note that this module does not implement the "keyval" storage method and

can't be used by anything other than archives.

Compatibility

=============

  ------ ---------------

  trunk  Should work

  0.11   Works

  0.10   Should work

  0.9    Does not work

  ------ ---------------

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`:

``` bash

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.

::: {.alert .alert-danger}

Since this is a destructive command, don't forget to backup your data

first.

Prosody should *not* be running while converting data.

:::

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.