view mod_storage_multi/README.markdown @ 4976:75b6e5df65f9

various: Improve error reporting if missing file server module on 0.12 If there is some error loading net.http.files then it would be swallowed by the pcall and then it would proceed to trying mod_http_files, which might cause unexpected behavior on 0.12 Ref #1765
author Kim Alvefur <zash@zash.se>
date Mon, 18 Jul 2022 22:47:54 +0200
parents a7fdab9c14e2
children
line wrap: on
line source

---
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"`.