---

summary: Multi-backend storage module (WIP)

labels:

- NeedDocs

- Stage-Alpha

...

Introduction

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

This module attemtps to provide a storage driver that is really multiple

storage drivers. This could be used for storage error tolerance or

caching of data in a faster storage driver.

Configuration

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

An example:

``` {.lua}

storage = "multi"

storage_multi_policy = "all"

storage_multi = {

    "memory",

    "internal",

    "sql"

}

```

Here data would be first read from or written to [mod\_storage\_memory],

then internal storage, then SQL storage. For reads, the first successful

read will be used. For writes, it depends on the `storage_multi_policy`

option. If set to `"all"`, then all storage backends must report success

for the write to be considered successful. Other options are `"one"` and

`"majority"`.