Deploy CockroachDB on Digital Ocean (Insecure)

This page shows you how to deploy an insecure multi-node CockroachDB cluster on Digital Ocean, using Digital Ocean's managed load balancing service to distribute client traffic.

Before you begin

Requirements

• Carefully review the Production Checklist and recommended Topology Patterns.

• You must have SSH access to each machine. This is necessary for distributing and starting CockroachDB binaries.

• Your network configuration must allow TCP communication on the following ports:

  • 26257 for intra-cluster and client-cluster communication
  • 8080 to expose your Admin UI

Recommendations

• Consider using a secure cluster instead. Using an insecure cluster comes with risks:

  • Your cluster is open to any client that can access any node's IP addresses.
  • Any user, even root, can log in without providing a password.
  • Any user, connecting as root, can read or write any data in your cluster.
  • There is no network encryption or authentication, and thus no confidentiality.

• Decide how you want to access your Admin UI:

  Access Level	Description
  Partially open	Set a firewall rule to allow only specific IP addresses to communicate on port 8080.
  Completely open	Set a firewall rule to allow all IP addresses to communicate on port 8080.
  Completely closed	Set a firewall rule to disallow all communication on port 8080. In this case, a machine with SSH access to a node could use an SSH tunnel to access the Admin UI.

• If all of your CockroachDB nodes and clients will run on Droplets in a single region, consider using private networking.

Step 1. Create Droplets

Create Droplets for each node you plan to have in your cluster. If you plan to run a sample workload against the cluster, create a separate droplet for that workload.

• Run at least 3 nodes to ensure survivability.

• Use any droplets except standard droplets with only 1 GB of RAM, which is below our minimum requirement. All Digital Ocean droplets use SSD storage.

For more details, see Hardware Recommendations and Cluster Topology.

Step 2. Synchronize clocks

CockroachDB requires moderate levels of clock synchronization to preserve data consistency. For this reason, when a node detects that its clock is out of sync with at least half of the other nodes in the cluster by 80% of the maximum offset allowed (500ms by default), it spontaneously shuts down. This avoids the risk of consistency anomalies, but it's best to prevent clocks from drifting too far in the first place by running clock synchronization software on each node.

ntpd should keep offsets in the single-digit milliseconds, so that software is featured here, but other methods of clock synchronization are suitable as well.

1. SSH to the first machine.

2. Disable timesyncd, which tends to be active by default on some Linux distributions:

   $ sudo timedatectl set-ntp no
   

   Verify that timesyncd is off:

   $ timedatectl
   

   Look for Network time on: no or NTP enabled: no in the output.

3. Install the ntp package:

   $ sudo apt-get install ntp
   

4. Stop the NTP daemon:

   $ sudo service ntp stop
   

5. Sync the machine's clock with Google's NTP service:

   $ sudo ntpd -b time.google.com
   

   To make this change permanent, in the /etc/ntp.conf file, remove or comment out any lines starting with server or pool and add the following lines:

   server time1.google.com iburst
   server time2.google.com iburst
   server time3.google.com iburst
   server time4.google.com iburst
   

   Restart the NTP daemon:

   $ sudo service ntp start
   

   Note:

   We recommend Google's NTP service because it handles "smearing" the leap second. If you use a different NTP service that doesn't smear the leap second, be sure to configure client-side smearing in the same way on each machine. See the Production Checklist for details.

6. Verify that the machine is using a Google NTP server:

   $ sudo ntpq -p
   

   The active NTP server will be marked with an asterisk.

7. Repeat these steps for each machine where a CockroachDB node will run.

Step 3. Set up load balancing

Each CockroachDB node is an equally suitable SQL gateway to your cluster, but to ensure client performance and reliability, it's important to use load balancing:

• Performance: Load balancers spread client traffic across nodes. This prevents any one node from being overwhelmed by requests and improves overall cluster performance (queries per second).

• Reliability: Load balancers decouple client health from the health of a single CockroachDB node. In cases where a node fails, the load balancer redirects client traffic to available nodes.

Digital Ocean offers fully-managed load balancers to distribute traffic between Droplets.

1. Create a Digital Ocean Load Balancer. Be sure to:
   • Set forwarding rules to route TCP traffic from the load balancer's port 26257 to port 26257 on the node Droplets.
   • Configure health checks to use HTTP port 8080 and path /health?ready=1. This health endpoint ensures that load balancers do not direct traffic to nodes that are live but not ready to receive requests.
2. Note the provisioned IP Address for the load balancer. You'll use this later to test load balancing and to connect your application to the cluster.

Step 4. Configure your network

Set up a firewall for each of your Droplets, allowing TCP communication on the following two ports:

• 26257 (tcp:26257) for inter-node communication (i.e., working as a cluster), for applications to connect to the load balancer, and for routing from the load balancer to nodes
• 8080 (tcp:8080) for exposing your Admin UI

For guidance, you can use Digital Ocean's guide to configuring firewalls based on the Droplet's OS:

• Ubuntu and Debian can use ufw.
• FreeBSD can use ipfw.
• Fedora can use iptables.
• CoreOS can use iptables.
• CentOS can use firewalld.

Step 5. Start nodes

You can start the nodes manually or automate the process using systemd.

For each initial node of your cluster, complete the following steps:

Note:

After completing these steps, nodes will not yet be live. They will complete the startup process and join together to form a cluster as soon as the cluster is initialized in the next step.

1. SSH to the machine where you want the node to run.

2. Download the CockroachDB archive for Linux, and extract the binary:

   $ curl https://binaries.cockroachdb.com/cockroach-v19.1.11.linux-amd64.tgz \
   | tar -xz
   

3. Copy the binary into the PATH:

   $ cp -i cockroach-v19.1.11.linux-amd64/cockroach /usr/local/bin/
   

   If you get a permissions error, prefix the command with sudo.

4. Run the cockroach start command:

   $ cockroach start \
   --insecure \
   --advertise-addr=<node1 address> \
   --join=<node1 address>,<node2 address>,<node3 address> \
   --cache=.25 \
   --max-sql-memory=.25 \
   --background
   

   This command primes the node to start, using the following flags:

   Flag	Description
   --insecure	Indicates that the cluster is insecure, with no network encryption or authentication.
   --advertise-addr	Specifies the IP address/hostname and port to tell other nodes to use. The port number can be omitted, in which case it defaults to 26257. This value must route to an IP address the node is listening on (with --listen-addr unspecified, the node listens on all IP addresses). In some networking scenarios, you may need to use --advertise-addr and/or --listen-addr differently. For more details, see Networking.
   --join	Identifies the address of 3-5 of the initial nodes of the cluster. These addresses should match the addresses that the target nodes are advertising.
   --cache --max-sql-memory	Increases the node's cache and temporary SQL memory size to 25% of available system memory to improve read performance and increase capacity for in-memory SQL processing. For more details, see Cache and SQL Memory Size.
   --background	Starts the node in the background so you gain control of the terminal to issue more commands.

   When deploying across multiple datacenters, or when there is otherwise high latency between nodes, it is recommended to set --locality as well. It is also required to use certain enterprise features. For more details, see Locality.

   For other flags not explicitly set, the command uses default values. For example, the node stores data in --store=cockroach-data and binds Admin UI HTTP requests to --http-addr=localhost:8080. To set these options manually, see Start a Node.

5. Repeat these steps for each additional node that you want in your cluster.

For each initial node of your cluster, complete the following steps:

Note:

After completing these steps, nodes will not yet be live. They will complete the startup process and join together to form a cluster as soon as the cluster is initialized in the next step.

1. SSH to the machine where you want the node to run. Ensure you are logged in as the root user.

2. Download the CockroachDB archive for Linux, and extract the binary:

   $ curl https://binaries.cockroachdb.com/cockroach-v19.1.11.linux-amd64.tgz \
   | tar -xz
   

3. Copy the binary into the PATH:

   $ cp -i cockroach-v19.1.11.linux-amd64/cockroach /usr/local/bin/
   

   If you get a permissions error, prefix the command with sudo.

4. Create the Cockroach directory:

   $ mkdir /var/lib/cockroach
   

5. Create a Unix user named cockroach:

   $ useradd cockroach
   

6. Change the ownership of Cockroach directory to the user cockroach:

   $ chown cockroach /var/lib/cockroach
   

7. Download the sample configuration template and save the file in the /etc/systemd/system/ directory:

   $ wget -qO- https://raw.githubusercontent.com/cockroachdb/docs/master/_includes/v19.1/prod-deployment/insecurecockroachdb.service
   

   Alternatively, you can create the file yourself and copy the script into it:

   [Unit]
   Description=Cockroach Database cluster node
   Requires=network.target
   [Service]
   Type=notify
   WorkingDirectory=/var/lib/cockroach
   ExecStart=/usr/local/bin/cockroach start --insecure --advertise-addr=<node1 address> --join=<node1 address>,<node2 address>,<node3 address> --cache=.25 --max-sql-memory=.25
   TimeoutStopSec=60
   Restart=always
   RestartSec=10
   StandardOutput=syslog
   StandardError=syslog
   SyslogIdentifier=cockroach
   User=cockroach
   [Install]
   WantedBy=default.target
   
   

8. In the sample configuration template, specify values for the following flags:

   Flag	Description
   --advertise-addr	Specifies the IP address/hostname and port to tell other nodes to use. The port number can be omitted, in which case it defaults to 26257. This value must route to an IP address the node is listening on (with --listen-addr unspecified, the node listens on all IP addresses). In some networking scenarios, you may need to use --advertise-addr and/or --listen-addr differently. For more details, see Networking.
   --join	Identifies the address of 3-5 of the initial nodes of the cluster. These addresses should match the addresses that the target nodes are advertising.

   When deploying across multiple datacenters, or when there is otherwise high latency between nodes, it is recommended to set --locality as well. It is also required to use certain enterprise features. For more details, see Locality.

   For other flags not explicitly set, the command uses default values. For example, the node stores data in --store=cockroach-data and binds Admin UI HTTP requests to --http-port=8080. To set these options manually, see Start a Node.

9. Start the CockroachDB cluster:

   $ systemctl start insecurecockroachdb
   

10. Repeat these steps for each additional node that you want in your cluster.

Note:

systemd handles node restarts in case of node failure. To stop a node without systemd restarting it, run systemctl stop insecurecockroachdb

Step 6. Initialize the cluster

On your local machine, complete the node startup process and have them join together as a cluster:

1. Install CockroachDB on your local machine, if you haven't already.

2. Run the cockroach init command, with the --host flag set to the address of any node:

   $ cockroach init --insecure --host=<address of any node>
   

   Each node then prints helpful details to the standard output, such as the CockroachDB version, the URL for the admin UI, and the SQL URL for clients.

Step 7. Test the cluster

CockroachDB replicates and distributes data behind-the-scenes and uses a Gossip protocol to enable each node to locate data across the cluster. Once a cluster is live, any node can be used as a SQL gateway.

When using a load balancer, you should issue commands directly to the load balancer, which then routes traffic to the nodes.

Use the built-in SQL client locally as follows:

1. On your local machine, launch the built-in SQL client, with the --host flag set to the address of the load balancer:

   $ cockroach sql --insecure --host=<address of load balancer>
   

2. Create an insecurenodetest database:

   > CREATE DATABASE insecurenodetest;
   

3. View the cluster's databases, which will include insecurenodetest:

   > SHOW DATABASES;
   

   +--------------------+
   |      Database      |
   +--------------------+
   | crdb_internal      |
   | information_schema |
   | insecurenodetest   |
   | pg_catalog         |
   | system             |
   +--------------------+
   (5 rows)
   

4. Use \q to exit the SQL shell.

Step 8. Run a sample workload

CockroachDB offers a pre-built workload binary for Linux that includes several load generators for simulating client traffic against your cluster. This step features CockroachDB's version of the TPC-C workload.

1. SSH to the machine where you want the run the sample TPC-C workload.

   This should be a machine that is not running a CockroachDB node.

2. Download workload and make it executable:

   $ wget https://edge-binaries.cockroachdb.com/cockroach/workload.LATEST ; chmod 755 workload.LATEST
   

3. Rename and copy workload into the PATH:

   $ cp -i workload.LATEST /usr/local/bin/workload
   

4. Start the TPC-C workload, pointing it at the IP address of the load balancer:

   $ workload run tpcc \
   --drop \
   --init \
   --duration=20m \
   --tolerate-errors \
   "postgresql://root@<IP ADDRESS OF LOAD BALANCER>:26257/tpcc?sslmode=disable"
   

   This command runs the TPC-C workload against the cluster for 20 minutes, loading 1 "warehouse" of data initially and then issuing about 12 queries per minute via 10 "worker" threads. These workers share SQL connections since individual workers are idle for long periods of time between queries.

   Tip:

   For more tpcc options, use workload run tpcc --help. For details about other load generators included in workload, use workload run --help.

5. To monitor the load generator's progress, open the Admin UI by pointing a browser to the address in the admin field in the standard output of any node on startup.

   Since the load generator is pointed at the load balancer, the connections will be evenly distributed across nodes. To verify this, click Metrics on the left, select the SQL dashboard, and then check the SQL Connections graph. You can use the Graph menu to filter the graph for specific nodes.

Step 9. Monitor the cluster

Despite CockroachDB's various built-in safeguards against failure, it is critical to actively monitor the overall health and performance of a cluster running in production and to create alerting rules that promptly send notifications when there are events that require investigation or intervention.

For details about available monitoring options and the most important events and metrics to alert on, see Monitoring and Alerting.

Step 10. Scale the cluster

You can start the nodes manually or automate the process using systemd.

For each additional node you want to add to the cluster, complete the following steps:

1. SSH to the machine where you want the node to run.

2. Download the CockroachDB archive for Linux, and extract the binary:

   $ curl https://binaries.cockroachdb.com/cockroach-v19.1.11.linux-amd64.tgz \
   | tar -xz
   

3. Copy the binary into the PATH:

   $ cp -i cockroach-v19.1.11.linux-amd64/cockroach /usr/local/bin/
   

   If you get a permissions error, prefix the command with sudo.

4. Run the cockroach start command, passing the new node's address as the --advertise-addr flag and pointing --join to the three existing nodes (also include --locality if you set it earlier).

   $ cockroach start \
   --insecure \
   --advertise-addr=<node4 address> \
   --join=<node1 address>,<node2 address>,<node3 address> \
   --cache=.25 \
   --max-sql-memory=.25 \
   --background
   

5. Update your load balancer to recognize the new node.

For each additional node you want to add to the cluster, complete the following steps:

1. SSH to the machine where you want the node to run. Ensure you are logged in as the root user.

2. Download the CockroachDB archive for Linux, and extract the binary:

   $ curl https://binaries.cockroachdb.com/cockroach-v19.1.11.linux-amd64.tgz \
   | tar -xz
   

3. Copy the binary into the PATH:

   $ cp -i cockroach-v19.1.11.linux-amd64/cockroach /usr/local/bin/
   

   If you get a permissions error, prefix the command with sudo.

4. Create the Cockroach directory:

   $ mkdir /var/lib/cockroach
   

5. Create a Unix user named cockroach:

   $ useradd cockroach
   

6. Change the ownership of Cockroach directory to the user cockroach:

   $ chown cockroach /var/lib/cockroach
   

7. Download the sample configuration template:

   $ wget -qO- https://raw.githubusercontent.com/cockroachdb/docs/master/_includes/v19.1/prod-deployment/insecurecockroachdb.service
   

   Alternatively, you can create the file yourself and copy the script into it:

   [Unit]
   Description=Cockroach Database cluster node
   Requires=network.target
   [Service]
   Type=notify
   WorkingDirectory=/var/lib/cockroach
   ExecStart=/usr/local/bin/cockroach start --insecure --advertise-addr=<node1 address> --join=<node1 address>,<node2 address>,<node3 address> --cache=.25 --max-sql-memory=.25
   TimeoutStopSec=60
   Restart=always
   RestartSec=10
   StandardOutput=syslog
   StandardError=syslog
   SyslogIdentifier=cockroach
   User=cockroach
   [Install]
   WantedBy=default.target
   
   

   Save the file in the /etc/systemd/system/ directory

8. Customize the sample configuration template for your deployment:

   Specify values for the following flags in the sample configuration template:

   Flag	Description
   --advertise-addr	Specifies the IP address/hostname and port to tell other nodes to use. The port number can be omitted, in which case it defaults to 26257. This value must route to an IP address the node is listening on (with --listen-addr unspecified, the node listens on all IP addresses). In some networking scenarios, you may need to use --advertise-addr and/or --listen-addr differently. For more details, see Networking.
   --join	Identifies the address of 3-5 of the initial nodes of the cluster. These addresses should match the addresses that the target nodes are advertising.

9. Repeat these steps for each additional node that you want in your cluster.

Step 11. Use the cluster

Now that your deployment is working, you can:

1. Implement your data model.
2. Create users and grant them privileges.
3. Connect your application. Be sure to connect your application to the Digital Ocean Load Balancer, not to a CockroachDB node.

See also

• Production Checklist
• Manual Deployment
• Orchestrated Deployment
• Monitoring and Alerting
• Performance Benchmarking
• Performance Tuning
• Local Deployment