+++ title = "Deployment on a cluster" weight = 5 +++ To run Garage in cluster mode, we recommend having at least 3 nodes. This will allow you to setup Garage for three-way replication of your data, the safest and most available mode proposed by Garage. We recommend first following the [quick start guide](@/documentation/quick-start/_index.md) in order to get familiar with Garage's command line and usage patterns. ## Preparing your environment ### Prerequisites To run a real-world deployment, make sure the following conditions are met: - You have at least three machines with sufficient storage space available. - Each machine has a public IP address which is reachable by other machines. It is highly recommended that you use IPv6 for this end-to-end connectivity. If IPv6 is not available, then using a mesh VPN such as [Nebula](https://github.com/slackhq/nebula) or [Yggdrasil](https://yggdrasil-network.github.io/) are approaches to consider in addition to building out your own VPN tunneling. - This guide will assume you are using Docker containers to deploy Garage on each node. Garage can also be run independently, for instance as a [Systemd service](@/documentation/cookbook/systemd.md). You can also use an orchestrator such as Nomad or Kubernetes to automatically manage Docker containers on a fleet of nodes. Before deploying Garage on your infrastructure, you must inventory your machines. For our example, we will suppose the following infrastructure with IPv6 connectivity: | Location | Name | IP Address | Disk Space | |----------|---------|------------|------------| | Paris | Mercury | fc00:1::1 | 1 TB | | Paris | Venus | fc00:1::2 | 2 TB | | London | Earth | fc00:B::1 | 2 TB | | Brussels | Mars | fc00:F::1 | 1.5 TB | Note that Garage will **always** store the three copies of your data on nodes at different locations. This means that in the case of this small example, the available capacity of the cluster is in fact only 1.5 TB, because nodes in Brussels can't store more than that. This also means that nodes in Paris and London will be under-utilized. To make better use of the available hardware, you should ensure that the capacity available in the different locations of your cluster is roughly the same. For instance, here, the Mercury node could be moved to Brussels; this would allow the cluster to store 2 TB of data in total. ### Best practices - If you have fast dedicated networking between all your nodes, and are planing to store very large files, bump the `block_size` configuration parameter to 10 MB (`block_size = 10485760`). - Garage stores its files in two locations: it uses a metadata directory to store frequently-accessed small metadata items, and a data directory to store data blocks of uploaded objects. Ideally, the metadata directory would be stored on an SSD (smaller but faster), and the data directory would be stored on an HDD (larger but slower). - For the data directory, Garage already does checksumming and integrity verification, so there is no need to use a filesystem such as BTRFS or ZFS that does it. We recommend using XFS for the data partition, as it has the best performance. EXT4 is not recommended as it has more strict limitations on the number of inodes, which might cause issues with Garage when large numbers of objects are stored. - If you only have an HDD and no SSD, it's fine to put your metadata alongside the data on the same drive. Having lots of RAM for your kernel to cache the metadata will help a lot with performance. Make sure to use the LMDB database engine, instead of Sled, which suffers from quite bad performance degradation on HDDs. Sled is still the default for legacy reasons, but is not recommended anymore. - For the metadata storage, Garage does not do checksumming and integrity verification on its own. If you are afraid of bitrot/data corruption, put your metadata directory on a BTRFS partition. Otherwise, just use regular EXT4 or XFS. - Having a single server with several storage drives is currently not very well supported in Garage ([#218](https://git.deuxfleurs.fr/Deuxfleurs/garage/issues/218)). For an easy setup, just put all your drives in a RAID0 or a ZFS RAIDZ array. If you're adventurous, you can try to format each of your disk as a separate XFS partition, and then run one `garage` daemon per disk drive, or use something like [`mergerfs`](https://github.com/trapexit/mergerfs) to merge all your disks in a single union filesystem that spreads load over them. ## Get a Docker image Our docker image is currently named `dxflrs/garage` and is stored on the [Docker Hub](https://hub.docker.com/r/dxflrs/garage/tags?page=1&ordering=last_updated). We encourage you to use a fixed tag (eg. `v0.8.0`) and not the `latest` tag. For this example, we will use the latest published version at the time of the writing which is `v0.8.0` but it's up to you to check [the most recent versions on the Docker Hub](https://hub.docker.com/r/dxflrs/garage/tags?page=1&ordering=last_updated). For example: ``` sudo docker pull dxflrs/garage:v0.8.0 ``` ## Deploying and configuring Garage On each machine, we will have a similar setup, especially you must consider the following folders/files: - `/etc/garage.toml`: Garage daemon's configuration (see below) - `/var/lib/garage/meta/`: Folder containing Garage's metadata, put this folder on a SSD if possible - `/var/lib/garage/data/`: Folder containing Garage's data, this folder will be your main data storage and must be on a large storage (e.g. large HDD) A valid `/etc/garage.toml` for our cluster would look as follows: ```toml metadata_dir = "/var/lib/garage/meta" data_dir = "/var/lib/garage/data" db_engine = "lmdb" replication_mode = "3" compression_level = 2 rpc_bind_addr = "[::]:3901" rpc_public_addr = "<this node's public IP>:3901" rpc_secret = "<RPC secret>" [s3_api] s3_region = "garage" api_bind_addr = "[::]:3900" root_domain = ".s3.garage" [s3_web] bind_addr = "[::]:3902" root_domain = ".web.garage" index = "index.html" ``` Check the following for your configuration files: - Make sure `rpc_public_addr` contains the public IP address of the node you are configuring. This parameter is optional but recommended: if your nodes have trouble communicating with one another, consider adding it. - Make sure `rpc_secret` is the same value on all nodes. It should be a 32-bytes hex-encoded secret key. You can generate such a key with `openssl rand -hex 32`. ## Starting Garage using Docker On each machine, you can run the daemon with: ```bash docker run \ -d \ --name garaged \ --restart always \ --network host \ -v /etc/garage.toml:/etc/garage.toml \ -v /var/lib/garage/meta:/var/lib/garage/meta \ -v /var/lib/garage/data:/var/lib/garage/data \ dxflrs/garage:v0.8.0 ``` It should be restarted automatically at each reboot. Please note that we use host networking as otherwise Docker containers can not communicate with IPv6. If you want to use `docker-compose`, you may use the following `docker-compose.yml` file as a reference: ```yaml version: "3" services: garage: image: dxflrs/garage:v0.8.0 network_mode: "host" restart: unless-stopped volumes: - /etc/garage.toml:/etc/garage.toml - /var/lib/garage/meta:/var/lib/garage/meta - /var/lib/garage/data:/var/lib/garage/data ``` Upgrading between Garage versions should be supported transparently, but please check the relase notes before doing so! To upgrade, simply stop and remove this container and start again the command with a new version of Garage. ## Controling the daemon The `garage` binary has two purposes: - it acts as a daemon when launched with `garage server` - it acts as a control tool for the daemon when launched with any other command Ensure an appropriate `garage` binary (the same version as your Docker image) is available in your path. If your configuration file is at `/etc/garage.toml`, the `garage` binary should work with no further change. You can also use an alias as follows to use the Garage binary inside your docker container: ```bash alias garage="docker exec -ti <container name> /garage" ``` You can test your `garage` CLI utility by running a simple command such as: ```bash garage status ``` At this point, nodes are not yet talking to one another. Your output should therefore look like follows: ``` Mercury$ garage status ==== HEALTHY NODES ==== ID Hostname Address Tag Zone Capacity 563e1ac825ee3323… Mercury [fc00:1::1]:3901 NO ROLE ASSIGNED ``` ## Connecting nodes together When your Garage nodes first start, they will generate a local node identifier (based on a public/private key pair). To obtain the node identifier of a node, once it is generated, run `garage node id`. This will print keys as follows: ```bash Mercury$ garage node id 563e1ac825ee3323aa441e72c26d1030d6d4414aeb3dd25287c531e7fc2bc95d@[fc00:1::1]:3901 Venus$ garage node id 86f0f26ae4afbd59aaf9cfb059eefac844951efd5b8caeec0d53f4ed6c85f332@[fc00:1::2]:3901 etc. ``` You can then instruct nodes to connect to one another as follows: ```bash # Instruct Venus to connect to Mercury (this will establish communication both ways) Venus$ garage node connect 563e1ac825ee3323aa441e72c26d1030d6d4414aeb3dd25287c531e7fc2bc95d@[fc00:1::1]:3901 ``` You don't nead to instruct all node to connect to all other nodes: nodes will discover one another transitively. Now if your run `garage status` on any node, you should have an output that looks as follows: ``` ==== HEALTHY NODES ==== ID Hostname Address Tag Zone Capacity 563e1ac825ee3323… Mercury [fc00:1::1]:3901 NO ROLE ASSIGNED 86f0f26ae4afbd59… Venus [fc00:1::2]:3901 NO ROLE ASSIGNED 68143d720f20c89d… Earth [fc00:B::1]:3901 NO ROLE ASSIGNED 212f7572f0c89da9… Mars [fc00:F::1]:3901 NO ROLE ASSIGNED ``` ## Creating a cluster layout We will now inform Garage of the disk space available on each node of the cluster as well as the zone (e.g. datacenter) in which each machine is located. This information is called the **cluster layout** and consists of a role that is assigned to each active cluster node. For our example, we will suppose we have the following infrastructure (Capacity, Identifier and Zone are specific values to Garage described in the following): | Location | Name | Disk Space | `Capacity` | `Identifier` | `Zone` | |----------|---------|------------|------------|--------------|--------------| | Paris | Mercury | 1 TB | `10` | `563e` | `par1` | | Paris | Venus | 2 TB | `20` | `86f0` | `par1` | | London | Earth | 2 TB | `20` | `6814` | `lon1` | | Brussels | Mars | 1.5 TB | `15` | `212f` | `bru1` | #### Node identifiers After its first launch, Garage generates a random and unique identifier for each nodes, such as: ``` 563e1ac825ee3323aa441e72c26d1030d6d4414aeb3dd25287c531e7fc2bc95d ``` Often a shorter form can be used, containing only the beginning of the identifier, like `563e`, which identifies the server "Mercury" located in "Paris" according to our previous table. The most simple way to match an identifier to a node is to run: ``` garage status ``` It will display the IP address associated with each node; from the IP address you will be able to recognize the node. #### Zones Zones are simply a user-chosen identifier that identify a group of server that are grouped together logically. It is up to the system administrator deploying Garage to identify what does "grouped together" means. In most cases, a zone will correspond to a geographical location (i.e. a datacenter). Behind the scene, Garage will use zone definition to try to store the same data on different zones, in order to provide high availability despite failure of a zone. #### Capacity Garage reasons on an abstract metric about disk storage that is named the *capacity* of a node. The capacity configured in Garage must be proportional to the disk space dedicated to the node. Capacity values must be **integers** but can be given any signification. Here we chose that 1 unit of capacity = 100 GB. Note that the amount of data stored by Garage on each server may not be strictly proportional to its capacity value, as Garage will priorize having 3 copies of data in different zones, even if this means that capacities will not be strictly respected. For example in our above examples, nodes Earth and Mars will always store a copy of everything each, and the third copy will have 66% chance of being stored by Venus and 33% chance of being stored by Mercury. #### Injecting the topology Given the information above, we will configure our cluster as follow: ```bash garage layout assign 563e -z par1 -c 10 -t mercury garage layout assign 86f0 -z par1 -c 20 -t venus garage layout assign 6814 -z lon1 -c 20 -t earth garage layout assign 212f -z bru1 -c 15 -t mars ``` At this point, the changes in the cluster layout have not yet been applied. To show the new layout that will be applied, call: ```bash garage layout show ``` Once you are satisfied with your new layout, apply it with: ```bash garage layout apply ``` **WARNING:** if you want to use the layout modification commands in a script, make sure to read [this page](@/documentation/operations/layout.md) first. ## Using your Garage cluster Creating buckets and managing keys is done using the `garage` CLI, and is covered in the [quick start guide](@/documentation/quick-start/_index.md). Remember also that the CLI is self-documented thanks to the `--help` flag and the `help` subcommand (e.g. `garage help`, `garage key --help`). Configuring S3-compatible applications to interact with Garage is covered in the [Integrations](@/documentation/connect/_index.md) section.