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This tutorial shows you how to manually deploy an insecure multi-node CockroachDB cluster on multiple machines, using HAProxy load balancers to distribute client traffic.
The --insecure flag used in this tutorial is intended for non-production testing only. To run CockroachDB in production, use a secure cluster instead.
To try CockroachDB Cloud instead of running CockroachDB yourself, refer to the .

Before you begin

Requirements

  • 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 and 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

  • Consider using a 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 DB Console:

Step 1. 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:
    Verify that timesyncd is off:
    Look for Network time on: no or NTP enabled: no in the output.
  3. Install the ntp package:
  4. Stop the NTP daemon:
  5. Sync the machine’s clock with Google’s NTP service:
    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:
    Restart the NTP daemon:
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.
  1. Verify that the machine is using a Google NTP server:
    The active NTP server will be marked with an asterisk.
  2. Repeat these steps for each machine where a CockroachDB node will run.

Step 2. 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:
    This command primes the node to start, using the following flags:
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 . 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 . 4. 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. .
  3. Create the Cockroach directory:
  4. Create a Unix user named cockroach:
  5. Change the ownership of the cockroach directory to the user cockroach:
  6. Download the sample configuration template and save the file in the /etc/systemd/system/ directory:
    Alternatively, you can create the file yourself and copy the script into it:
Previously, the sample configuration file set TimeoutStopSec to 60 seconds. This recommendation has been lengthened to 300 seconds, to give the cockroach process more time to stop gracefully.
  1. In the sample configuration template, specify values for the following flags:
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 . 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-port=8080. To set these options manually, see . 8. Start the CockroachDB cluster:
  1. Configure systemd to start CockroachDB automatically after a reboot:
  2. 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 insecurecockroachdb

Step 3. Initialize the cluster

On your local machine, complete the node startup process and have them join together as a cluster:
  1. on your local machine, if you haven’t already.
  2. Run the command, with the --host flag set to the address of any node:
    Each node then prints helpful details to the , such as the CockroachDB version, the URL for the DB Console, and the SQL URL for clients.

Step 4. 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:
  2. Create an insecurenodetest database:
  3. View the cluster’s databases, which will include insecurenodetest:
  4. Use \q to exit the SQL shell.

Step 5. 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.
With a single load balancer, client connections are resilient to node failure, but the load balancer itself is a point of failure. It’s therefore best to make load balancing resilient as well by using multiple load balancing instances, with a mechanism like floating IPs or DNS to select load balancers for clients.
HAProxy is one of the most popular open-source TCP load balancers, and CockroachDB includes a built-in command for generating a configuration file that is preset to work with your running cluster, so we feature that tool here.
  1. SSH to the machine where you want to run HAProxy.
  2. Install HAProxy:
  3. .
  4. Run the command, specifying the address of any CockroachDB node:
    By default, the generated configuration file is called haproxy.cfg and looks as follows, with the server addresses pre-populated correctly:
    The file is preset with the minimal configurations needed to work with your running cluster:
For full details on these and other configuration settings, see the HAProxy Configuration Manual.
  1. Start HAProxy, with the -f flag pointing to the haproxy.cfg file:
  2. Repeat these steps for each additional instance of HAProxy you want to run.

Step 6. 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, see .
  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. .
  3. Use the command to load the initial schema and data, pointing it at the IP address of the load balancer:
  4. Use the cockroach workload command to run the workload for 10 minutes:
    You’ll see per-operation statistics print to standard output every second:
    After the specified duration (10 minutes in this case), the workload will stop and you’ll see totals printed to standard output:
For more tpcc options, use cockroach workload run tpcc --help. For details about other workloads built into the cockroach binary, use cockroach workload --help.
  1. 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 7. 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 8. 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. .
  3. 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).
  4. 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. .
  3. Create the Cockroach directory:
  4. Create a Unix user named cockroach:
  5. Change the ownership of the cockroach directory to the user cockroach:
  6. Download the sample configuration template:
    Alternatively, you can create the file yourself and copy the script into it:
    Previously, the sample configuration file set TimeoutStopSec to 60 seconds. This recommendation has been lengthened to 300 seconds, to give the cockroach process more time to stop gracefully. Save the file in the /etc/systemd/system/ directory
  7. Customize the sample configuration template for your deployment: Specify values for the following flags in the sample configuration template:
  1. Repeat these steps for each additional node that you want in your cluster.

Step 9. Use the cluster

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