Deploy CockroachDB on Digital Ocean

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

If you are only testing CockroachDB, or you are not concerned with protecting network communication with TLS encryption, you can use an insecure cluster instead. Select Insecure above for instructions.

To try CockroachDB Cloud instead of running CockroachDB yourself, refer to the .

Before you begin

Requirements

• You must have locally. This is necessary for generating and managing your deployment’s certificates.

• 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 DB Console

• Carefully review the , including supported hardware and software, and the recommended .

• Do not run multiple node processes on the same VM or machine. This defeats CockroachDB’s replication and causes the system to be a single point of failure. Instead, start each node on a separate VM or machine.

• To start a node with multiple disks or SSDs, provide a separate --store flag for each disk when starting the cockroach process on the node. For more details about stores, see .

  If you start a node with multiple --store flags, it is not possible to scale back down to only using a single store on the node. Instead, you must decommission the node and start a new node with the updated --store.

• When starting each node, use the flag to describe the node’s location, for example, --locality=region=west,zone=us-west-1. The key-value pairs should be ordered from most to least inclusive, and the keys and order of key-value pairs must be the same on all nodes.

• When deploying in a single availability zone:

  • To be able to tolerate the failure of any 1 node, use at least 3 nodes with the . In this case, if 1 node fails, each range retains 2 of its 3 replicas, a majority.
  • To be able to tolerate 2 simultaneous node failures, use at least 5 nodes and to 5. The replication factor for is 5 by default, so no adjustments are needed for internal data. In this case, if 2 nodes fail at the same time, each range retains 3 of its 5 replicas, a majority.

• When deploying across multiple availability zones:

  • To be able to tolerate the failure of 1 entire AZ in a region, use at least 3 AZs per region and set --locality on each node to spread data evenly across regions and AZs. In this case, if 1 AZ goes offline, the 2 remaining AZs retain a majority of replicas.
  • To ensure that ranges are split evenly across nodes, use the same number of nodes in each AZ. This is to avoid overloading any nodes with excessive resource consumption.

• When deploying across multiple regions:

  • To be able to tolerate the failure of 1 entire region, use at least 3 regions.

Recommendations

• Decide how you want to access your DB Console:

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 DB Console.

• 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 .
• 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 and .

Step 2. Synchronize clocks

CockroachDB requires moderate levels of 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
   

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 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 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.

If you would prefer to use HAProxy instead of Digital Ocean’s managed load balancing, see the tutorial for guidance.

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 DB Console

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. Generate certificates

You can use cockroach cert commands or to generate security certificates. This section features the cockroach cert commands.

Locally, you’ll need to :

• A certificate authority (CA) key pair ( ca.crt and ca.key ).
• A node key pair for each node, issued to its IP addresses and any common names the machine uses, as well as to the IP addresses and common names for machines running load balancers.
• A client key pair for the root user. You’ll use this to run a sample workload against the cluster as well as some cockroach client commands from your local machine.

Before beginning, it’s useful to collect each of your machine’s internal and external IP addresses, as well as any server names you want to issue certificates for.

1. on your local machine, if you haven’t already.

2. Create two directories:

   $ mkdir certs
   
   $ mkdir my-safe-directory
   
   • certs: You’ll generate your CA certificate and all node and client certificates and keys in this directory and then upload some of the files to your nodes.
   • my-safe-directory: You’ll generate your CA key in this directory and then reference the key when generating node and client certificates. After that, you’ll keep the key safe and secret; you will not upload it to your nodes.

3. Create the CA certificate and key:

   $ cockroach cert create-ca \
   --certs-dir=certs \
   --ca-key=my-safe-directory/ca.key
   

4. Create the certificate and key for the first node, issued to all common names you might use to refer to the node as well as to the load balancer instances:

   $ cockroach cert create-node \
   <node1 internal IP address> \
   <node1 external IP address> \
   <node1 hostname>  \
   <other common names for node1> \
   localhost \
   127.0.0.1 \
   <load balancer IP address> \
   <load balancer hostname>  \
   <other common names for load balancer instances> \
   --certs-dir=certs \
   --ca-key=my-safe-directory/ca.key
   

5. Upload the CA certificate and node certificate and key to the first node:

   $ ssh <username>@<node1 address "mkdir certs"
   
   $ scp certs/ca.crt \
   certs/node.crt \
   certs/node.key \
   <username>@<node1 address:~/certs
   

6. Delete the local copy of the node certificate and key:

   $ rm certs/node.crt certs/node.key
   

This is necessary because the certificates and keys for additional nodes will also be named node.crt and node.key. As an alternative to deleting these files, you can run the next cockroach cert create-node commands with the --overwrite flag.

7. Create the certificate and key for the second node, issued to all common names you might use to refer to the node as well as to the load balancer instances:

   $ cockroach cert create-node \
   <node2 internal IP address> \
   <node2 external IP address> \
   <node2 hostname>  \
   <other common names for node2> \
   localhost \
   127.0.0.1 \
   <load balancer IP address> \
   <load balancer hostname>  \
   <other common names for load balancer instances> \
   --certs-dir=certs \
   --ca-key=my-safe-directory/ca.key
   

8. Upload the CA certificate and node certificate and key to the second node:

   $ ssh <username>@<node2 address "mkdir certs"
   
   $ scp certs/ca.crt \
   certs/node.crt \
   certs/node.key \
   <username>@<node2 address:~/certs
   

9. Repeat steps 6 - 8 for each additional node.

10. Create a client certificate and key for the root user:

    $ cockroach cert create-client \
    root \
    --certs-dir=certs \
    --ca-key=my-safe-directory/ca.key
    

11. Upload the CA certificate and client certificate and key to the machine where you will run a sample workload:

    $ ssh <username>@<workload address "mkdir certs"
    
    $ scp certs/ca.crt \
    certs/client.root.crt \
    certs/client.root.key \
    <username>@<workload address:~/certs
    

    In later steps, you’ll also use the root user’s certificate to run client commands from your local machine. If you might also want to run cockroach client commands directly on a node (e.g., for local debugging), you’ll need to copy the root user’s certificate and key to that node as well.

On accessing the DB Console in a later step, your browser will consider the CockroachDB-created certificate invalid and you’ll need to click through a warning message to get to the UI. You can avoid this issue by .

Step 6. 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:

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. Visit and download the full binary of CockroachDB to the node.

2. On the node, follow the instructions to .

3. Run the command:

   $ cockroach start \
   --certs-dir=certs \
   --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
--certs-dir	Specifies the directory where you placed the ca.crt file and the node.crt and node.key files for the node.
--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 .
--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 size to 25% of available system memory to improve read performance. The capacity for in-memory SQL processing defaults to 25% of system memory but can be raised, if necessary, to increase the number of simultaneous client connections allowed by the node as well as the node’s capacity for in-memory processing of rows when using ORDER BY, GROUP BY, DISTINCT, joins, and window functions. For more details, see .
--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. For more details, see .

For other flags not explicitly set, the command uses default values. For example, the node stores data in --store=cockroach-data and binds DB Console HTTP requests to --http-addr=<node1 address:8080. To set these options manually, see .

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

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

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-v23.2.29.linux-amd64.tgz \
   | tar -xz
   

3. Copy the binary into the PATH:

   $ cp -i cockroach-v23.2.29.linux-amd64/cockroach /usr/local/bin/
   

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

4. CockroachDB uses custom-built versions of the libraries. Copy these libraries to the location where CockroachDB expects to find them:

   $ mkdir -p /usr/local/lib/cockroach
   
   $ cp -i cockroach-v23.2.29.linux-amd64/lib/libgeos.so /usr/local/lib/cockroach/
   
   $ cp -i cockroach-v23.2.29.linux-amd64/lib/libgeos_c.so /usr/local/lib/cockroach/
   

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

5. Create the Cockroach directory:

   $ mkdir /var/lib/cockroach
   

6. Create a Unix user named cockroach:

   $ useradd cockroach
   

7. Move the certs directory to the cockroach directory.

   $ mv certs /var/lib/cockroach/
   

8. Change the ownership of the cockroach directory to the user cockroach:

   $ chown -R cockroach /var/lib/cockroach
   

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

   curl -o securecockroachdb.service https://raw.githubusercontent.com/cockroachlabs/docs/main/src/current/_includes/v23.2/prod-deployment/securecockroachdb.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 --certs-dir=certs --advertise-addr=<node1 address --join=<node1 address,<node2 address,<node3 address --cache=.25 --max-sql-memory=.25
   TimeoutStopSec=300
   Restart=always
   RestartSec=10
   StandardOutput=syslog
   StandardError=syslog
   SyslogIdentifier=cockroach
   User=cockroach
   [Install]
   WantedBy=default.target
   

10. 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 .
--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. For more details, see .

For other flags not explicitly set, the command uses default values. For example, the node stores data in --store=cockroach-data and binds DB Console HTTP requests to --http-addr=localhost:8080. To set these options manually, see . 11. Start the CockroachDB cluster:

$ systemctl start securecockroachdb

12. Configure systemd to start CockroachDB automatically after a reboot:

    systemctl enable securecockroachdb
    

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

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

Step 7. Initialize the cluster

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

$ cockroach init --certs-dir=certs --host=<address of any node on --join list

After running this command, each node prints helpful details to the , such as the CockroachDB version, the URL for the DB Console, and the SQL URL for clients.

Step 8. 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 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 --certs-dir=certs --host=<address of load balancer
   

2. Create a securenodetest database:

   > CREATE DATABASE securenodetest;
   

3. View the cluster’s databases, which will include securenodetest:

   > SHOW DATABASES;
   
   +--------------------+
   |      Database      |
   +--------------------+
   | crdb_internal      |
   | information_schema |
   | securenodetest     |
   | pg_catalog         |
   | system             |
   +--------------------+
   (5 rows)
   

4. Use \q to exit the SQL shell.

Step 9. Run a sample workload

CockroachDB comes with a number of for simulating client traffic. This step features CockroachDB’s version of the TPC-C workload.

Be sure that you have configured your network to allow traffic from the application to the load balancer. In this case, you will run the sample workload on one of your machines. The traffic source should therefore be the internal (private) IP address of that machine.

For comprehensive guidance on benchmarking CockroachDB with TPC-C, refer to .

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

   This should be a machine that is not running a CockroachDB node, and it should already have a certs directory containing ca.crt, client.root.crt, and client.root.key files.

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

   $ curl https://binaries.cockroachdb.com/cockroach-v23.2.29.linux-amd64.tgz \
   | tar -xz
   

3. Copy the binary into the PATH:

   $ cp -i cockroach-v23.2.29.linux-amd64/cockroach /usr/local/bin/
   

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

4. Use the command to load the initial schema and data, pointing it at the IP address of the load balancer:

   $ cockroach workload init tpcc \
   'postgresql://root@<IP ADDRESS OF LOAD BALANCER>:26257/tpcc?sslmode=verify-full&sslrootcert=certs/ca.crt&sslcert=certs/client.root.crt&sslkey=certs/client.root.key'
   

5. Use the cockroach workload command to run the workload for 10 minutes:

   $ cockroach workload run tpcc \
   --duration=10m \
   'postgresql://root@<IP ADDRESS OF LOAD BALANCER>:26257/tpcc?sslmode=verify-full&sslrootcert=certs/ca.crt&sslcert=certs/client.root.crt&sslkey=certs/client.root.key'
   

   You’ll see per-operation statistics print to standard output every second:

   _elapsed___errors__ops/sec(inst)___ops/sec(cum)__p50(ms)__p95(ms)__p99(ms)_pMax(ms)
         1s        0         1443.4         1494.8      4.7      9.4     27.3     67.1 transfer
         2s        0         1686.5         1590.9      4.7      8.1     15.2     28.3 transfer
         3s        0         1735.7         1639.0      4.7      7.3     11.5     28.3 transfer
         4s        0         1542.6         1614.9      5.0      8.9     12.1     21.0 transfer
         5s        0         1695.9         1631.1      4.7      7.3     11.5     22.0 transfer
         6s        0         1569.2         1620.8      5.0      8.4     11.5     15.7 transfer
         7s        0         1614.6         1619.9      4.7      8.1     12.1     16.8 transfer
         8s        0         1344.4         1585.6      5.8     10.0     15.2     31.5 transfer
         9s        0         1351.9         1559.5      5.8     10.0     16.8     54.5 transfer
        10s        0         1514.8         1555.0      5.2      8.1     12.1     16.8 transfer
   ...
   

   After the specified duration (10 minutes in this case), the workload will stop and you’ll see totals printed to standard output:

   _elapsed___errors_____ops(total)___ops/sec(cum)__avg(ms)__p50(ms)__p95(ms)__p99(ms)_pMax(ms)__result
     600.0s        0         823902         1373.2      5.8      5.5     10.0     15.2    209.7
   

For more tpcc options, use cockroach workload run tpcc --help. For details about other workloads built into the cockroach binary, use cockroach workload --help.

6. To monitor the load generator’s progress, open the 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 10. Monitor the cluster

Despite CockroachDB’s various , 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 .

Step 11. 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 -o cockroach-v23.2.29.linux-amd64.tgz https://binaries.cockroachdb.com/cockroach-v23.2.29.linux-amd64.tgz; tar xzvf cockroach-v23.2.29.linux-amd64.tgz
   

3. Copy the binary into the PATH:

   $ cp -i cockroach-v23.2.29.linux-amd64/cockroach /usr/local/bin/
   

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

4. Run the 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 \
   --certs-dir=certs \
   --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-v23.2.29.linux-amd64.tgz \
   | tar -xz
   

3. Copy the binary into the PATH:

   $ cp -i cockroach-v23.2.29.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. Move the certs directory to the cockroach directory.

   $ mv certs /var/lib/cockroach/
   

7. Change the ownership of the cockroach directory to the user cockroach:

   $ chown -R cockroach /var/lib/cockroach
   

8. Download the sample configuration template:

   curl -o securecockroachdb.service https://raw.githubusercontent.com/cockroachlabs/docs/master/_includes/v23.2/prod-deployment/securecockroachdb.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 --certs-dir=certs --advertise-addr=<node1 address --join=<node1 address,<node2 address,<node3 address --cache=.25 --max-sql-memory=.25
   TimeoutStopSec=300
   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.

9. 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 .
--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.

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

Step 12. Use the database

Now that your deployment is working, you can:

1. .
2. and .
3. . Be sure to connect your application to the load balancer, not to a CockroachDB node.
4. of your data.

You may also want to adjust the way the cluster replicates data. For example, by default, a multi-node cluster replicates all data 3 times; you can change this replication factor or create additional rules for replicating individual databases and tables differently. For more information, see .

When running a cluster of 5 nodes or more, it’s safest to to 5, even if you do not do so for user data. For the cluster as a whole to remain available, the ranges for this internal data must always retain a majority of their replicas.

See also