Set up a local cluster

Configuring local clusters for testing and development

For testing and development deployments, the quickest and easiest way is to configure a local cluster. For a production deployment, refer to the clustering section.

Local standalone cluster

Starting a cluster

Run the following to deploy an etcd cluster as a standalone cluster:

1. $ ./etcd
2. ...

If the etcd binary is not present in the current working directory, it might be located either at $GOPATH/bin/etcd or at /usr/local/bin/etcd. Run the command appropriately.

The running etcd member listens on localhost:2379 for client requests.

Interacting with the cluster

Use etcdctl to interact with the running cluster:

  1. Store an example key-value pair in the cluster:

1. $ ./etcdctl put foo bar 2. OK

If OK is printed, storing key-value pair is successful. 2. Retrieve the value of foo:

1. $ ./etcdctl get foo 2. bar

If bar is returned, interaction with the etcd cluster is working as expected.

Local multi-member cluster

Starting a cluster

A Procfile at the base of the etcd git repository is provided to easily configure a local multi-member cluster. To start a multi-member cluster, navigate to the root of the etcd source tree and perform the following:

  1. Install goreman to control Procfile-based applications:

1. $ go install github.com/mattn/goreman@latest 2. Start a cluster with goreman using etcd’s stock Procfile:

1. $ goreman -f Procfile start

The members start running. They listen on localhost:2379, localhost:22379, and localhost:32379 respectively for client requests.

Interacting with the cluster

Use etcdctl to interact with the running cluster:

  1. Print the list of members:

1. $ etcdctl --write-out=table --endpoints=localhost:2379 member list

The list of etcd members are displayed as follows:

1. +------------------+---------+--------+------------------------+------------------------+ 2. | ID | STATUS | NAME | PEER ADDRS | CLIENT ADDRS | 3. +------------------+---------+--------+------------------------+------------------------+ 4. | 8211f1d0f64f3269 | started | infra1 | http://127.0.0.1:2380 | http://127.0.0.1:2379 | 5. | 91bc3c398fb3c146 | started | infra2 | http://127.0.0.1:22380 | http://127.0.0.1:22379 | 6. | fd422379fda50e48 | started | infra3 | http://127.0.0.1:32380 | http://127.0.0.1:32379 | 7. +------------------+---------+--------+------------------------+------------------------+ 2. Store an example key-value pair in the cluster:

1. $ etcdctl put foo bar 2. OK

If OK is printed, storing key-value pair is successful.

Testing fault tolerance

To exercise etcd’s fault tolerance, kill a member and attempt to retrieve the key.

  1. Identify the process name of the member to be stopped.

The Procfile lists the properties of the multi-member cluster. For example, consider the member with the process name, etcd2. 2. Stop the member:

1. # kill etcd2 2. $ goreman run stop etcd2 3. Store a key:

1. $ etcdctl put key hello 2. OK 4. Retrieve the key that is stored in the previous step:

1. $ etcdctl get key 2. hello 5. Retrieve a key from the stopped member:

1. $ etcdctl --endpoints=localhost:22379 get key

The command should display an error caused by connection failure:

1. 2017/06/18 23:07:35 grpc: Conn.resetTransport failed to create client transport: connection error: desc = "transport: dial tcp 127.0.0.1:22379: getsockopt: connection refused"; Reconnecting to "localhost:22379" 2. Error: grpc: timed out trying to connect 6. Restart the stopped member:

1. $ goreman run restart etcd2 7. Get the key from the restarted member:

1. $ etcdctl --endpoints=localhost:22379 get key 2. hello

Restarting the member re-establish the connection. etcdctl will now be able to retrieve the key successfully. To learn more about interacting with etcd, read interacting with etcd section.

Last modified April 18, 2023: Fix instructions for installing goreman. (964f7ab)