Backend store
Enterprise Edition
Tarantool Cluster Manager is a part of the Enterprise Edition.
Tarantool Cluster Manager uses an underlying data store (backend store) for its entities: users, roles, cluster connections, settings, and other objects that you manipulate in TCM. The backend store can be either an etcd or a Tarantool cluster.
For better reliability and scalability, the backend store works independently from TCM. For example, it can be the same ectd or Tarantool cluster that you use as a centralized configuration storage. This makes TCM stateless: all objects created or modified in its web UI are saved to the backend store, and nothing is stored inside the TCM instances themselves. Any number of instances can duplicate each other when connected to the same backend store. If you stop all instances, the store still contains their objects. You can continue working with them right after starting a new instance.
In addition to using an external backend store, you can run TCM with an embedded etcd or Tarantool instance to use as the backend store.
On this page, you will learn to connect TCM to backend stores of both types, or start TCM with an embedded backend store.
The TCM backend store requires the same configuration as Tarantool centralized configuration storage. Follow the instructions in Setting up a configuration storage to set up a backend store.
Note
If you already have the centralized configuration store for your Tarantool clusters, you can use it as a TCM backend store as well.
The TCM’s connection to its backend store is configured using the storage.*
configuration options. The storage.provider
option selects the store type. It can be either etcd
or tarantool
.
To use an etcd cluster as a TCM backend store, set the storage.provider
option
to etcd
and specify connection parameters in storage.etcd.*
options.
A minimal etcd configuration includes the storage endpoints:
storage:
provider: etcd
etcd:
endpoints:
- http://127.0.0.1:2379
If authentication is enabled in etcd, specify storage.etcd.username
and storage.etcd.password
:
storage:
provider: etcd
etcd:
endpoints:
- http://127.0.0.1:2379
username: etcduser
password: secret
The TCM data is stored in etcd under the prefix specified in storage.etcd.prefix
.
By default, the prefix is /tcm
. If you want to change it or store data of
different TCM instances separately in one etcd cluster, set the prefix explicitly:
storage:
provider: etcd
etcd:
endpoints:
- http://127.0.0.1:2379
prefix: /tcm2
Other storage.etcd.*
options configure various aspects of the etcd store connection,
such as network timeouts and limits or TLS parameters.
For the full list of the etcd TCM backend store options, see the
TCM configuration reference.
To use a Tarantool cluster as a TCM backend store, set the storage.provider
option
to tarantool
and specify connection parameters in storage.tarantool.*
options.
A minimal configuration includes the one or more addresses of
the backend store instances:
storage:
provider: tarantool
tarantool:
addr: http://127.0.0.1:3301
Or:
storage:
provider: tarantool
tarantool:
addrs:
- http://127.0.0.1:3301
- http://127.0.0.1:3302
- http://127.0.0.1:3303
If authentication is enabled in the backend store, specify storage.tarantool.username
and storage.tarantool.password
:
storage:
provider: tarantool
tarantool:
addr: http://127.0.0.1:3301
username: tarantooluser
password: secret
The TCM data is stored in the Tarantool-based backend store under the prefix
specified in storage.tarantool.prefix
.
By default, the prefix is /tcm
. If you want to change it or store data of
different TCM instances separately in one Tarantool cluster, set the prefix explicitly:
storage:
provider: tarantool
tarantool:
addr: http://127.0.0.1:3301
username: tarantooluser
password: secret
prefix: /tcm2
Other storage.tarantool.*
options configure various aspects of TCM connection
to the Tarantool-based backend store, such as network timeouts and limits or TLS parameters.
For the full list of the Tarantool-based TCM backend store options, see the
TCM configuration reference.
For development purposes, you can start TCM with an embedded backend store. This is useful for local runs when you don’t have or don’t need an external backend store.
An embedded TCM backend store is a single instance of etcd or Tarantool that is started automatically on the same host during the TCM startup. It runs in the background until TCM is stopped. The embedded backend store is persistent: if you start TCM again with the same backend store configuration, it restores the TCM data from the previous runs.
Note
To start a clean instance of TCM, remove the working directory of the
embedded backend store specified in the storage.etcd.embed.workdir
or
storage.tarantool.embed.workdir
option.
The embedded backend store parameters are configured using the storage.etcd.embed.*
options
for etcd or storage.tarantool.embed.*
options for a Tarantool-based store.
To start TCM with an embedded etcd with default settings, set storage.etcd.embed.enabled
to true
and leave other storage.*
options default:
storage.etcd.embed.enabled: true
You can use the following call to get TCM running with embedded etcd without a configuration file:
$ tcm --storage.etcd.embed.enabled
To start TCM with an embedded Tarantool storage with default settings:
- set
storage.provider
totarantool
- set
storage.tarantool.embed.enabled
totrue
storage:
provider: tarantool
tarantool.embed.enabled: true
With command-line arguments:
$ tcm --storage.provider=tarantool --storage.tarantool.embed.enabled
You can tune the embedded backend store, for example, enable and configure TLS on it
or change its working directories or startup arguments. To set specific parameters,
specify the corresponding storage.etcd.embed.*
or storage.tarantool.embed.*
options. For the full list of configuration options of embedded backend stores, see the
TCM configuration reference.
To simulate the production environment, you can form a distributed multi-instance cluster from embedded stores of multiple TCM instances. To do this, configure each TCM instance’s embedded store to join each other.
For etcd, provide the embedded store clustering parameters storage.etcd.embed.*
and specify the endpoints in storage.etcd.endpoints
. The options that configure
embedded etcd mostly match the etcd configuration options. For more information
about these options, see the etcd documentation.
Below are example configurations of three TCM instances that start with embedded etcd instances and form an etcd cluster from them:
First instance:
http.port: 8080 storage: provider: etcd etcd: endpoints: - http://127.0.0.1:2379 - http://127.0.0.1:22379 - http://127.0.0.1:32379 embed: enabled: true name: infra1 endpoints: http://127.0.0.1:2379 advertises: http://127.0.0.1:2379 initial-cluster-state: new initial-cluster: infra1=http://127.0.0.1:12380,infra2=http://127.0.0.1:22380,infra3=http://127.0.0.1:32380 initial-cluster-token: etcd-cluster-1 peer-endpoints: http://127.0.0.1:12380 peer-advertises: http://127.0.0.1:12380 workdir: node1.etcd
Second instance:
http.port: 8081 storage: provider: etcd etcd: endpoints: - http://127.0.0.1:2379 - http://127.0.0.1:22379 - http://127.0.0.1:32379 embed: enabled: true name: infra2 endpoints: http://127.0.0.1:22379 advertises: http://127.0.0.1:22379 initial-cluster-state: new initial-cluster: infra1=http://127.0.0.1:12380,infra2=http://127.0.0.1:22380,infra3=http://127.0.0.1:32380 initial-cluster-token: etcd-cluster-1 peer-endpoints: http://127.0.0.1:22380 peer-advertises: http://127.0.0.1:22380 workdir: node2.etcd
Third instance:
http.port: 8082 storage: provider: etcd etcd: endpoints: - http://127.0.0.1:2379 - http://127.0.0.1:22379 - http://127.0.0.1:32379 embed: enabled: true name: infra3 endpoints: http://127.0.0.1:32379 advertises: http://127.0.0.1:32379 initial-cluster-state: new initial-cluster: infra1=http://127.0.0.1:12380,infra2=http://127.0.0.1:22380,infra3=http://127.0.0.1:32380 initial-cluster-token: etcd-cluster-1 peer-endpoints: http://127.0.0.1:32380 peer-advertises: http://127.0.0.1:32380 workdir: node3.etcd
To set up a cluster from embedded Tarantool-based backend stores:
- Specify the Tarantool cluster configuration in
storage.tarantool.embed.config
(as a plain text) orstorage.tarantool.embed.config-file
(as a YAML file). - Assign an instance name from this configuration to each instance using
storage.tarantool.embed.args
to each embedded store.
Below are example configurations of three TCM instances that start with embedded Tarantool-based backend stores and form a cluster from them:
First instance:
http.port: 8080 storage: provider: tarantool tarantool: addrs: - http://127.0.0.1:3301 - http://127.0.0.1:3302 - http://127.0.0.1:3303 embed: enabled: true config-filename: config.yml workdir: node1.tarantool args: - --name - instance-001 - --config - config.yml
Second instance:
http.port: 8081 storage: provider: tarantool tarantool: addrs: - http://127.0.0.1:3301 - http://127.0.0.1:3302 - http://127.0.0.1:3303 embed: enabled: true config-filename: config.yml workdir: node2.tarantool args: - --name - instance-002 - --config - config.yml
Third instance:
http.port: 8082 storage: provider: tarantool tarantool: addrs: - http://127.0.0.1:3301 - http://127.0.0.1:3302 - http://127.0.0.1:3303 embed: enabled: true config-filename: config.yml workdir: node3.tarantool args: - --name - instance-003 - --config - config.yml