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 Cloud Quickstart.
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:
26257for intra-cluster and client-cluster communication8080to expose your DB Console
Carefully review the Production Checklist and recommended Topology Patterns.
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, you can use either of these approaches:
- Configure the disks or SSDs as a single RAID volume, then pass the RAID volume to the
--storeflag when starting thecockroachprocess on the node. - Provide a separate
--storeflag for each disk when starting thecockroachprocess on the node. For more details about stores, see Start a Node.
Warning:If you start a node with multiple--storeflags, 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.- Configure the disks or SSDs as a single RAID volume, then pass the RAID volume to the
When starting each node, use the
--localityflag 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
default3-way replication factor. 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 increase the
defaultreplication factor for user data to 5. The replication factor for important internal data 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.
- To be able to tolerate the failure of any 1 node, use at least 3 nodes with the
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
--localityon 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.
- To be able to tolerate the failure of 1 entire AZ in a region, use at least 3 AZs per region and set
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 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 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.
Step 1. 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.
SSH to the first machine.
Disable
timesyncd, which tends to be active by default on some Linux distributions:$ sudo timedatectl set-ntp noVerify that
timesyncdis off:$ timedatectlLook for
Network time on: noorNTP enabled: noin the output.Install the
ntppackage:$ sudo apt-get install ntpStop the NTP daemon:
$ sudo service ntp stopSync the machine's clock with Google's NTP service:
$ sudo ntpd -b time.google.comTo make this change permanent, in the
/etc/ntp.conffile, remove or comment out any lines starting withserverorpooland add the following lines:server time1.google.com iburst server time2.google.com iburst server time3.google.com iburst server time4.google.com iburstRestart the NTP daemon:
$ sudo service ntp startNote: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.
Verify that the machine is using a Google NTP server:
$ sudo ntpq -pThe active NTP server will be marked with an asterisk.
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.
Visit Releases and download the full binary of CockroachDB to the node.
On the node, follow the instructions to install CockroachDB.
Run the
cockroach startcommand:$ cockroach start \ --insecure \ --advertise-addr=<node1 address> \ --join=<node1 address>,<node2 address>,<node3 address> \ --cache=.25 \ --max-sql-memory=.25 \ --backgroundThis command primes the node to start, using the following flags:
Flag Description --insecureIndicates that the cluster is insecure, with no network encryption or authentication. --advertise-addrSpecifies 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-addrunspecified, the node listens on all IP addresses).
In some networking scenarios, you may need to use--advertise-addrand/or--listen-addrdifferently. For more details, see Networking.--joinIdentifies 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-memoryIncreases 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 Cache and SQL Memory Size.--backgroundStarts 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
--localityas 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-dataand binds DB Console HTTP requests to--http-addr=localhost:8080. To set these options manually, see Start a Node.
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.
SSH to the machine where you want the node to run. Ensure you are logged in as the
rootuser.Download the CockroachDB archive for Linux, and extract the binary:
$ curl https://binaries.cockroachdb.com/cockroach-v23.1.30.linux-amd64.tgz \ | tar -xzCopy the binary into the
PATH:$ cp -i cockroach-v23.1.30.linux-amd64/cockroach /usr/local/bin/If you get a permissions error, prefix the command with
sudo.CockroachDB uses custom-built versions of the GEOS libraries. Copy these libraries to the location where CockroachDB expects to find them:
$ mkdir -p /usr/local/lib/cockroach$ cp -i cockroach-v23.1.30.linux-amd64/lib/libgeos.so /usr/local/lib/cockroach/$ cp -i cockroach-v23.1.30.linux-amd64/lib/libgeos_c.so /usr/local/lib/cockroach/If you get a permissions error, prefix the command with
sudo.Create the Cockroach directory:
$ mkdir /var/lib/cockroachCreate a Unix user named
cockroach:$ useradd cockroachChange the ownership of the
cockroachdirectory to the usercockroach:$ chown cockroach /var/lib/cockroachDownload the sample configuration template and save the file in the
/etc/systemd/system/directory:curl -o insecurecockroachdb.service https://raw.githubusercontent.com/cockroachdb/docs/main/src/current/_includes/v23.1/prod-deployment/insecurecockroachdb.serviceAlternatively, 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=300 Restart=always RestartSec=10 StandardOutput=syslog StandardError=syslog SyslogIdentifier=cockroach User=cockroach [Install] WantedBy=default.targetNote:Previously, the sample configuration file set
TimeoutStopSecto 60 seconds. This recommendation has been lengthened to 300 seconds, to give thecockroachprocess more time to stop gracefully.In the sample configuration template, specify values for the following flags:
Flag Description --advertise-addrSpecifies 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-addrunspecified, the node listens on all IP addresses).
In some networking scenarios, you may need to use--advertise-addrand/or--listen-addrdifferently. For more details, see Networking.--joinIdentifies 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
--localityas 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-dataand binds DB Console HTTP requests to--http-port=8080. To set these options manually, see Start a Node.Start the CockroachDB cluster:
$ systemctl start insecurecockroachdbConfigure
systemdto start CockroachDB automatically after a reboot:systemctl enable insecurecockroachdbRepeat 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:
Install CockroachDB on your local machine, if you haven't already.
Run the
cockroach initcommand, with the--hostflag set to the address of any node:$ cockroach init --insecure --host=<address of any node on --join list>Each node then prints helpful details to the standard output, 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 built-in SQL client locally as follows:
On your local machine, launch the built-in SQL client, with the
--hostflag set to the address of the load balancer:$ cockroach sql --insecure --host=<address of load balancer>Create an
insecurenodetestdatabase:> CREATE DATABASE insecurenodetest;View the cluster's databases, which will include
insecurenodetest:> SHOW DATABASES;+--------------------+ | Database | +--------------------+ | crdb_internal | | information_schema | | insecurenodetest | | pg_catalog | | system | +--------------------+ (5 rows)Use
\qto 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.
Tip: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.
SSH to the machine where you want to run HAProxy.
Install HAProxy:
$ apt-get install haproxy
Download the CockroachDB archive for Linux, and extract the binary:
$ curl https://binaries.cockroachdb.com/cockroach-v23.1.30.linux-amd64.tgz \ | tar -xzCopy the binary into the
PATH:$ cp -i cockroach-v23.1.30.linux-amd64/cockroach /usr/local/bin/
If you get a permissions error, prefix the command with sudo.
Run the
cockroach gen haproxycommand, specifying the address of any CockroachDB node:$ cockroach gen haproxy --insecure \ --host=<address of any node> \ --port=26257By default, the generated configuration file is called
haproxy.cfgand looks as follows, with theserveraddresses pre-populated correctly:global maxconn 4096 defaults mode tcp # Timeout values should be configured for your specific use. # See: https://cbonte.github.io/haproxy-dconv/1.8/configuration.html#4-timeout%20connect timeout connect 10s timeout client 1m timeout server 1m # TCP keep-alive on client side. Server already enables them. option clitcpka listen psql bind :26257 mode tcp balance roundrobin option httpchk GET /health?ready=1 server cockroach1 <node1 address>:26257 check port 8080 server cockroach2 <node2 address>:26257 check port 8080 server cockroach3 <node3 address>:26257 check port 8080The file is preset with the minimal configurations needed to work with your running cluster:
Field Description timeout connecttimeout clienttimeout serverTimeout values that should be suitable for most deployments. bindThe port that HAProxy listens on. This is the port clients will connect to and thus needs to be allowed by your network configuration.
This tutorial assumes HAProxy is running on a separate machine from CockroachDB nodes. If you run HAProxy on the same machine as a node (not recommended), you'll need to change this port, as26257is likely already being used by the CockroachDB node.balanceThe balancing algorithm. This is set to roundrobinto ensure that connections get rotated amongst nodes (connection 1 on node 1, connection 2 on node 2, etc.). Check the HAProxy Configuration Manual for details about this and other balancing algorithms.option httpchkThe HTTP endpoint that HAProxy uses to check node health. /health?ready=1ensures that HAProxy doesn't direct traffic to nodes that are live but not ready to receive requests.serverFor each included node, this field specifies the address the node advertises to other nodes in the cluster, i.e., the addressed pass in the --advertise-addrflag on node startup. Make sure hostnames are resolvable and IP addresses are routable from HAProxy.Note:For full details on these and other configuration settings, see the HAProxy Configuration Manual.
Start HAProxy, with the
-fflag pointing to thehaproxy.cfgfile:
$ haproxy -f haproxy.cfg
- 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 built-in workloads 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 Performance Benchmarking.
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.
Download the CockroachDB archive for Linux, and extract the binary:
$ curl https://binaries.cockroachdb.com/cockroach-v23.1.30.linux-amd64.tgz \ | tar -xzCopy the binary into the
PATH:$ cp -i cockroach-v23.1.30.linux-amd64/cockroach /usr/local/bin/If you get a permissions error, prefix the command with
sudo.Use the
cockroach workloadcommand 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=disable'Use the
cockroach workloadcommand to run the workload for 10 minutes:$ cockroach workload run tpcc \ --duration=10m \ 'postgresql://root@<IP ADDRESS OF LOAD BALANCER>:26257/tpcc?sslmode=disable'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 15.2 209.7Tip:For more
tpccoptions, usecockroach workload run tpcc --help. For details about other workloads built into thecockroachbinary, usecockroach workload --help.To monitor the load generator's progress, open the DB Console by pointing a browser to the address in the
adminfield 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 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 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:
SSH to the machine where you want the node to run.
Download the CockroachDB archive for Linux, and extract the binary:
$ curl https://binaries.cockroachdb.com/cockroach-v23.1.30.linux-amd64.tgz \ | tar -xzCopy the binary into the
PATH:$ cp -i cockroach-v23.1.30.linux-amd64/cockroach /usr/local/bin/If you get a permissions error, prefix the command with
sudo.Run the
cockroach startcommand, passing the new node's address as the--advertise-addrflag and pointing--jointo the three existing nodes (also include--localityif you set it earlier).$ cockroach start \ --insecure \ --advertise-addr=<node4 address> \ --join=<node1 address>,<node2 address>,<node3 address> \ --cache=.25 \ --max-sql-memory=.25 \ --backgroundUpdate your load balancer to recognize the new node.
For each additional node you want to add to the cluster, complete the following steps:
SSH to the machine where you want the node to run. Ensure you are logged in as the
rootuser.Download the CockroachDB archive for Linux, and extract the binary:
$ curl https://binaries.cockroachdb.com/cockroach-v23.1.30.linux-amd64.tgz \ | tar -xzCopy the binary into the
PATH:$ cp -i cockroach-v23.1.30.linux-amd64/cockroach /usr/local/bin/If you get a permissions error, prefix the command with
sudo.Create the Cockroach directory:
$ mkdir /var/lib/cockroachCreate a Unix user named
cockroach:$ useradd cockroachChange the ownership of the
cockroachdirectory to the usercockroach:$ chown cockroach /var/lib/cockroachDownload the sample configuration template:
$ wget -qO- https://raw.githubusercontent.com/cockroachdb/docs/master/_includes/v23.1/prod-deployment/insecurecockroachdb.serviceAlternatively, 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=300 Restart=always RestartSec=10 StandardOutput=syslog StandardError=syslog SyslogIdentifier=cockroach User=cockroach [Install] WantedBy=default.targetNote:Previously, the sample configuration file set
TimeoutStopSecto 60 seconds. This recommendation has been lengthened to 300 seconds, to give thecockroachprocess more time to stop gracefully.Save the file in the
/etc/systemd/system/directoryCustomize the sample configuration template for your deployment:
Specify values for the following flags in the sample configuration template:
Flag Description --advertise-addrSpecifies 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-addrunspecified, the node listens on all IP addresses).
In some networking scenarios, you may need to use--advertise-addrand/or--listen-addrdifferently. For more details, see Networking.--joinIdentifies the address of 3-5 of the initial nodes of the cluster. These addresses should match the addresses that the target nodes are advertising. 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:
- Implement your data model.
- Create users and grant them privileges.
- Connect your application. Be sure to connect your application to the load balancer, not to a CockroachDB node.
- Take backups 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 Replication Controls.
When running a cluster of 5 nodes or more, it's safest to increase the replication factor for important internal data 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.