open-vault/website/content/docs/concepts/integrated-storage/index.mdx

---
layout: docs
page_title: Integrated Storage
description: Learn about the integrated raft storage in Vault.
---

# Integrated Storage

Vault supports a number of storage options for the durable storage of Vault's
information. As of Vault 1.4 an Integrated Storage option is offered. This
storage backend does not rely on any third party systems, implements high
availability semantics, supports Enterprise Replication features, and provides
backup/restore workflows.

The option stores Vault's data on the server's filesystem and
uses a consensus protocol to replicate data to each server in the cluster. More
information on the internals of Integrated Storage can be found in the
[Integrated Storage internals
documentation](/docs/internals/integrated-storage/). Additionally, the
[Configuration](/docs/configuration/storage/raft/) docs can help in configuring
Vault to use Integrated Storage.

The sections below go into various details on how to operate Vault with
Integrated Storage.

## Server-to-Server Communication

Once nodes are joined to one another they begin to communicate using mTLS over
Vault's cluster port. The cluster port defaults to `8201`. The TLS information
is exchanged at join time and is rotated on a cadence.

A requirement for Integrated Storage is that the
[`cluster_addr`](/docs/concepts/ha#per-node-cluster-address) configuration option
is set. This allows Vault to assign an address to the node ID at join time.

## Cluster Membership

This section will outline how to bootstrap and manage a cluster of Vault nodes
running Integrated Storage.

Integrated Storage is bootstrapped during the [initialization
process](https://learn.hashicorp.com/vault/getting-started/deploy#initializing-the-vault),
and results in a cluster of size 1. Depending on the [desired deployment
size](/docs/internals/integrated-storage/#deployment-table), nodes can be joined
to the active Vault node.

### Joining Nodes

Joining is the process of taking an uninitialized Vault node and making it a
member of an existing cluster. In order to authenticate the new node to the
cluster it must use the same seal mechanism. If using a Auto Unseal the node
must be configured to use the same KMS provider and Key as the cluster it's
attempting to join. If using a Shamir seal the unseal keys must be provided to
the new node before the join process can complete. Once a node has successfully
joined, data from the active node can begin to replicate to it. Once a node has
been joined it cannot be re-joined to a different cluster.

You can either join the node automatically via the config file or manually through the
API (both methods described below). When joining a node, the API address of the leader node must be used. We
recommend setting the [`api_addr`](/docs/concepts/ha#direct-access) configuration
option on all nodes to make joining simpler.

#### `retry_join` Configuration

This method enables setting one, or more, target leader nodes in the config file.
When an uninitialized Vault server starts up it will attempt to join each potential
leader that is defined, retrying until successful. When one of the specified
leaders become active this node will successfully join. When using Shamir seal,
the joined nodes will still need to be unsealed manually. When using Auto Unseal
the node will be able to join and unseal automatically.

An example [`retry_join`](/docs/configuration/storage/raft#retry_join-stanza)
config can be seen below:

```hcl
storage "raft" {
  path    = "/var/raft/"
  node_id = "node3"

  retry_join {
    leader_api_addr = "https://node1.vault.local:8200"
  }
  retry_join {
    leader_api_addr = "https://node2.vault.local:8200"
  }
}
```

Note, in each [`retry_join`](/docs/configuration/storage/raft#retry_join-stanza)
stanza, you may provide a single
[`leader_api_addr`](/docs/configuration/storage/raft#leader_api_addr) or
[`auto_join`](/docs/configuration/storage/raft#auto_join) value. When a cloud
[`auto_join`](/docs/configuration/storage/raft#auto_join) configuration value is
provided, Vault will use [go-discover](https://github.com/hashicorp/go-discover)
to automatically attempt to discover and resolve potential Raft leader
addresses.

See the go-discover
[README](https://github.com/hashicorp/go-discover/blob/master/README.md) for
details on the format of the [`auto_join`](/docs/configuration/storage/raft#auto_join) value.

```hcl
storage "raft" {
  path    = "/var/raft/"
  node_id = "node3"

  retry_join {
    auto_join = "provider=aws region=eu-west-1 tag_key=vault tag_value=... access_key_id=... secret_access_key=..."
  }
}
```

By default, Vault will attempt to reach discovered peers using HTTPS and port 8200. Operators may override these through the
[`auto_join_scheme`](/docs/configuration/storage/raft#auto_join_scheme) and
[`auto_join_port`](/docs/configuration/storage/raft#auto_join_port) fields
respectively.

```hcl
storage "raft" {
  path    = "/var/raft/"
  node_id = "node3"

  retry_join {
    auto_join = "provider=aws region=eu-west-1 tag_key=vault tag_value=... access_key_id=... secret_access_key=..."
    auto_join_scheme = "http"
    auto_join_port = 8201
  }
}
```

#### Join from the CLI

Alternatively you can use the [`join` CLI
command](/docs/commands/operator/raft/#join) or the API to join a node. The
active node's API address will need to be specified:

```shell-session
$ vault operator raft join https://node1.vault.local:8200
```

#### Non-Voting Nodes (Enterprise Only)

Nodes that are joined to a cluster can be specified as non-voters. A non-voting
node has all of Vault's data replicated to it, but does not contribute to the
quorum count. This can be used in conjunction with [Performance
Standby](/docs/enterprise/performance-standby/) nodes to add read scalability to
a cluster in cases where a high volume of reads to servers are needed.

```shell-session
$ vault operator raft join -non-voter https://node1.vault.local:8200
```

### Removing Peers

Removing a peer node is a necessary step when you no longer want the node in the
cluster. This could happen if the node is rotated for a new one, the hostname
permanently changes and can no longer be accessed, you're attempting to shrink
the size of the cluster, or for many other reasons. Removing the peer will
ensure the cluster stays at the desired size, and that quorum is maintained.

To remove the peer you can issue a
[`remove-peer`](/docs/commands/operator/raft#remove-peer) command and provide the
node ID you wish to remove:

```shell-session
$ vault operator raft remove-peer node1
Peer removed successfully!
```

### Listing Peers

To see the current peer set for the cluster you can issue a
[`list-peers`](/docs/commands/operator/raft#list-peers) command. All the voting
nodes that are listed here contribute to the quorum and a majority must be alive
for Integrated Storage to continue to operate.

```shell-session
$ vault operator raft list-peers
Node     Address                   State       Voter
----     -------                   -----       -----
node1    node1.vault.local:8201    follower    true
node2    node2.vault.local:8201    follower    true
node3    node3.vault.local:8201    leader      true
```

## Integrated Storage and TLS

We've glossed over some details in the above sections on bootstrapping clusters.
The instructions are sufficient for most cases, but some users have run into
problems when using auto-join and TLS in conjunction with things like auto-scaling.
The issue is that [go-discover](https://github.com/hashicorp/go-discover) on
most platforms returns IPs (not hostnames), and because the IPs aren't knowable
in advance, the TLS certificates used to secure the Vault API port don't contain
these IPs in their IP SANs.

### Vault networking recap

Before we explore solutions to this problem, let's recapitulate how Vault nodes
speak to one another.

Vault exposes two TCP ports: [the API port](/docs/configuration#api_addr) and
[the cluster port](/docs/configuration#cluster_addr).

The API port is where clients send their Vault HTTP requests.

For a single-node Vault cluster you don't worry about a cluster port as it won't be used.

When you have multiple nodes, you also need a cluster port. This is used by Vault
nodes to issue RPCs to one another, e.g. to forward requests from a standby node
to the active node, or when Raft is in use, to handle leader election and
replication of stored data.

The cluster port is secured using a TLS certificate that the Vault active node
generates internally. It's clear how this can work when not using integrated
storage: every node has at least read access to storage, so once the active
node has persisted the certificate, the standby nodes can fetch it, and all
agree on how cluster traffic should be encrypted.

It's less clear how this works with Integrated Storage, as there is a chicken
and egg problem. Nodes don't have a shared view of storage until the raft
cluster has been formed, but we're trying to form the raft cluster! To solve
this problem, a Vault node must speak to another Vault node using the API port
instead of the cluster port. This is currently the only situation in which
OSS Vault does this (Vault Enterprise also does something similar when setting
up replication.)

- `node2` wants to join the cluster, so issues challenge API request to existing member `node1`
- `node1` replies to challenge request with (1) an encrypted random UUID and (2) seal config
- `node2` must decrypt UUID using seal; if using auto-unseal can do it directly, if using Shamir must wait for user to provide enough unseal keys to perform decryption
- `node2` sends decrypted UUID back to `node1` using answer API
- `node1` sees `node2` can be trusted (since it has seal access) and replies with a bootstrap package which includes the cluster TLS certificate and private key
- `node2` gets sent a raft snapshot over the cluster port

After this procedure the new node will never again send traffic to the API port.
All subsequent inter-node communication will use the cluster port.

![Raft Join Process](/img/raft-join-detailed.png)

### Assisted raft join techniques

The simplest option is to do it by hand: issue [`raft join`](/docs/commands/operator/raft#join) commands specifying the explicit names
or IPs of the nodes to join to. In this section we look at other TLS-compatible
options that lend themselves more to automation.

#### Autojoin with TLS servername

As of Vault 1.6.2, the simplest option might be to specify a
[`leader_tls_servername`](/docs/configuration/storage/raft#leader_tls_servername)
in the [`retry_join`](/docs/configuration/storage/raft#retry_join-stanza) stanza
which matches a [DNS
SAN](https://en.wikipedia.org/wiki/Subject_Alternative_Name) in the certificate.

Note that names in a certificate's DNS SAN don't actually have to be registered
in a DNS server. Your nodes may have no names found in DNS, while still
using certificate(s) that contain this shared `servername` in their DNS SANs.

#### Autojoin but constrain CIDR, list all possible IPs in certificate

If all the vault node IPs are assigned from a small subnet, e.g. a `/28`, it
becomes practical to put all the IPs that exist in that subnet into the IP SANs
of the TLS certificate the nodes will share.

The drawback here is that the cluster may someday outgrow the CIDR and changing
it may be a pain. For similar reasons this solution may be impractical when
using non-voting nodes and dynamically scaling clusters.

#### Load balancer instead of autojoin

Most Vault instances are going to have a load balancer (LB) between clients and
the Vault nodes. In that case, the LB knows how to route traffic to working
Vault nodes, and there's no need for auto-join: we can just use
[`retry_join`](/docs/configuration/storage/raft#retry_join-stanza) with the LB
address as the target.

One potential issue here: some users want a public facing LB for clients to
connect to Vault, but aren't comfortable with Vault internal traffic
egressing from the internal network it normally runs on.

## Outage Recovery

### Quorum Maintained

This section outlines the steps to take when a single server or multiple servers
are in a failed state but quorum is still maintained. This means the remaining
alive servers are still operational, can elect a leader, and are able to process
write requests.

If the failed server is recoverable, the best option is to bring it back online
and have it reconnect to the cluster with the same host address. This will return
the cluster to a fully healthy state.

If this is impractical, you need to remove the failed server. Usually, you can
issue a [`remove-peer`](/docs/commands/operator/raft#remove-peer) command to
remove the failed server if it's still a member of the cluster.

If the [`remove-peer`](/docs/commands/operator/raft#remove-peer) command isn't
possible or you'd rather manually re-write the cluster membership a
[`raft/peers.json`](#manual-recovery-using-peers-json) file can be written to
the configured data directory.

### Quorum Lost

In the event that multiple servers are lost, causing a loss of quorum and a
complete outage, partial recovery is still possible.

If the failed servers are recoverable, the best option is to bring them back
online and have them reconnect to the cluster using the same host addresses.
This will return the cluster to a fully healthy state.

If the failed servers are not recoverable, partial recovery is possible using
data on the remaining servers in the cluster. There may be data loss in this
situation because multiple servers were lost, so information about what's
committed could be incomplete. The recovery process implicitly commits all
outstanding Raft log entries, so it's also possible to commit data that was
uncommitted before the failure.

See the section below on manual recovery using
[`peers.json`](#manual-recovery-using-peers-json) for details of the recovery
procedure. You include only the remaining servers in the
[`peers.json`](#manual-recovery-using-peers-json) recovery file. The
cluster should be able to elect a leader once the remaining servers are all
restarted with an identical
[`peers.json`](#manual-recovery-using-peers-json) configuration.

Any servers you introduce later can be fresh with totally clean data
directories and joined using Vault's join command.

In extreme cases, it should be possible to recover with just a single remaining
server by starting that single server with itself as the only peer in the
[`peers.json`](#manual-recovery-using-peers-json) recovery file.

### Manual Recovery Using peers.json

Using `raft/peers.json` for recovery can cause uncommitted Raft log entries to be
implicitly committed, so this should only be used after an outage where no other
option is available to recover a lost server. Make sure you don't have any
automated processes that will put the peers file in place on a periodic basis.

To begin, stop all remaining servers.

The next step is to go to the [configured data
path](/docs/configuration/storage/raft/#path) of each Vault server. Inside that
directory, there will be a `raft/` sub-directory. We need to create a
`raft/peers.json` file. The file should be formatted as a JSON array containing
the node ID, `address:port`, and suffrage information of each Vault server you
wish to be in the cluster:

```json
[
  {
    "id": "node1",
    "address": "node1.vault.local:8201",
    "non_voter": false
  },
  {
    "id": "node2",
    "address": "node2.vault.local:8201",
    "non_voter": false
  },
  {
    "id": "node3",
    "address": "node3.vault.local:8201",
    "non_voter": false
  }
]
```

- `id` `(string: <required>)` - Specifies the node ID of the server. This can be
  found in the config file, or inside the `node-id` file in the server's data
  directory if it was auto-generated.
- `address` `(string: <required>)` - Specifies the host and port of the server. The
  port is the server's cluster port.
- `non_voter` `(bool: <false>)` - This controls whether the server is a non-voter.
  If omitted, it will default to false, which is typical for most clusters. This
  is an enterprise only feature.

Create entries for all servers. You must confirm that servers you do not
include here have indeed failed and will not later rejoin the cluster. Ensure
that this file is the same across all remaining server nodes.

At this point, you can restart all the remaining servers. The cluster should be
in an operable state again. One of the nodes should claim leadership and become
active.

### Other Recovery Methods

For other, non-quorum related recovery [Vault's
recovery](/docs/concepts/recovery-mode/) mode can be used.