---
id: deploy-bare-metal
title: Deploy a cluster on bare metal
sidebar_label: Bare metal
---


> ### Tips
>
> 1. Single-cluster Pulsar installations should be sufficient for all but the most ambitious use cases. If you are interested in experimenting with
> Pulsar or using Pulsar in a startup or on a single team, you had better opt for a single cluster. If you do need to run a multi-cluster Pulsar instance,
> see the guide [here](deploy-bare-metal-multi-cluster.md).
>
> 2. If you want to use all builtin [Pulsar IO](io-overview.md) connectors in your Pulsar deployment, you need to download `apache-pulsar-io-connectors`
> package and install `apache-pulsar-io-connectors` under `connectors` directory in the pulsar directory on every broker node or on every function-worker node if you
> have run a separate cluster of function workers for [Pulsar Functions](functions-overview.md).
>
> 3. If you want to use [Tiered Storage](concepts-tiered-storage.md) feature in your Pulsar deployment, you need to download `apache-pulsar-offloaders`
> package and install `apache-pulsar-offloaders` under `offloaders` directory in the pulsar directory on every broker node. For more details of how to configure
> this feature, you can refer to the [Tiered storage cookbook](cookbooks-tiered-storage.md).

Deploying a Pulsar cluster involves doing the following (in order):

* Deploy a [ZooKeeper](#deploy-a-zookeeper-cluster) cluster (optional)
* Initialize [cluster metadata](#initialize-cluster-metadata)
* Deploy a [BookKeeper](#deploy-a-bookkeeper-cluster) cluster
* Deploy one or more Pulsar [brokers](#deploy-pulsar-brokers)

## Preparation

### Requirements

> If you already have an existing zookeeper cluster and want to reuse it, you do not need to prepare the machines
> for running ZooKeeper.

To run Pulsar on bare metal, you had better have the following:

* At least 6 Linux machines or VMs
  * 3 for running [ZooKeeper](https://zookeeper.apache.org)
  * 3 for running a Pulsar broker, and a [BookKeeper](https://bookkeeper.apache.org) bookie
* A single [DNS](https://en.wikipedia.org/wiki/Domain_Name_System) name covering all of the Pulsar broker hosts

> If you do not have enough machines, or try out Pulsar in cluster mode (and expand the cluster later),
> you can even deploy Pulsar in one node, where Zookeeper, bookie and broker are run in the same machine.

> If you do not have a DNS server, you can use multi-host in service URL instead.

Each machine in your cluster needs to have [Java 8](http://www.oracle.com/technetwork/java/javase/downloads/index.html) or higher version of Java installed.

The following is a diagram showing the basic setup:

![alt-text](assets/pulsar-basic-setup.png)

In this diagram, connecting clients need to be able to communicate with the Pulsar cluster using a single URL, in this case `pulsar-cluster.acme.com` abstracts over all of the message-handling brokers. Pulsar message brokers run on machines alongside BookKeeper bookies; brokers and bookies, in turn, rely on ZooKeeper.

### Hardware considerations

When you deploy a Pulsar cluster, keep in mind the following basic better choices when you do the capacity planning.

#### ZooKeeper

For machines running ZooKeeper, you had better use lighter-weight machines or VMs. Pulsar uses ZooKeeper only for periodic coordination-related and configuration-related tasks, *not* for basic operations. If you run Pulsar on [Amazon Web Services](https://aws.amazon.com/) (AWS), for example, a [t2.small](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/t2-instances.html) instance might likely suffice.

#### Bookies and Brokers

For machines running a bookie and a Pulsar broker, you had better use more powerful machines. For an AWS deployment, for example, [i3.4xlarge](https://aws.amazon.com/blogs/aws/now-available-i3-instances-for-demanding-io-intensive-applications/) instances may be appropriate. On those machines you can use the following:

* Fast CPUs and 10Gbps [NIC](https://en.wikipedia.org/wiki/Network_interface_controller) (for Pulsar brokers)
* Small and fast [solid-state drives](https://en.wikipedia.org/wiki/Solid-state_drive) (SSDs) or [hard disk drives](https://en.wikipedia.org/wiki/Hard_disk_drive) (HDDs) with a [RAID](https://en.wikipedia.org/wiki/RAID) controller and a battery-backed write cache (for BookKeeper bookies)

## Install the Pulsar binary package

> You need to install the Pulsar binary package on *each machine in the cluster*, including machines running [ZooKeeper](#deploy-a-zookeeper-cluster) and [BookKeeper](#deploy-a-bookkeeper-cluster).

To get started deploying a Pulsar cluster on bare metal, you need to download a binary tarball release in one of the following ways:

* By clicking on the link below directly, which automatically triggers a download:
  * <a href="pulsar:binary_release_url" download>Pulsar {{pulsar:version}} binary release</a>
* From the Pulsar [downloads page](pulsar:download_page_url)
* From the Pulsar [releases page](https://github.com/apache/pulsar/releases/latest) on [GitHub](https://github.com)
* Using [wget](https://www.gnu.org/software/wget):

```bash
$ wget pulsar:binary_release_url
```

Once you download the tarball, untar it and `cd` into the resulting directory:

```bash
$ tar xvzf apache-pulsar-{{pulsar:version}}-bin.tar.gz
$ cd apache-pulsar-{{pulsar:version}}
```

The untarred directory contains the following subdirectories:

Directory | Contains
:---------|:--------
`bin` |[command-line tools](reference-cli-tools.md) of Pulsar, such as [`pulsar`](reference-cli-tools.md#pulsar) and [`pulsar-admin`](reference-pulsar-admin.md)
`conf` | Configuration files for Pulsar, including for [broker configuration](reference-configuration.md#broker), [ZooKeeper configuration](reference-configuration.md#zookeeper), and more
`data` | The data storage directory that ZooKeeper and BookKeeper use
`lib` | The [JAR](https://en.wikipedia.org/wiki/JAR_(file_format)) files that Pulsar uses
`logs` | Logs that the installation creates

## [Install Builtin Connectors (optional)]( https://pulsar.apache.org/docs/en/next/standalone/#install-builtin-connectors-optional)

> Since Pulsar releases `2.1.0-incubating`, Pulsar releases a separate binary distribution, containing all the `builtin` connectors.
> If you want to enable those `builtin` connectors, you can follow the instructions as below; otherwise you can
> skip this section for now.

To get started using builtin connectors, you need to download the connectors tarball release on every broker node in one of the following ways:

* by clicking the link below and downloading the release from an Apache mirror:

  * <a href="pulsar:connector_release_url" download>Pulsar IO Connectors {{pulsar:version}} release</a>

* from the Pulsar [downloads page](pulsar:download_page_url)
* from the Pulsar [releases page](https://github.com/apache/pulsar/releases/latest)
* using [wget](https://www.gnu.org/software/wget):

  ```shell
  $ wget pulsar:connector_release_url/{connector}-{{pulsar:version}}.nar
  ```

Once you download the nar file, copy the file to directory `connectors` in the pulsar directory, 
for example, if you download the connector file `pulsar-io-aerospike-{{pulsar:version}}.nar`:

```bash
$ mkdir connectors
$ mv pulsar-io-aerospike-{{pulsar:version}}.nar connectors

$ ls connectors
pulsar-io-aerospike-{{pulsar:version}}.nar
...
```

## [Install Tiered Storage Offloaders (optional)](https://pulsar.apache.org/docs/en/next/standalone/#install-tiered-storage-offloaders-optional)

> Since Pulsar release `2.2.0`, Pulsar releases a separate binary distribution, containing the tiered storage offloaders.
> If you want to enable tiered storage feature, you can follow the instructions as below; otherwise you can
> skip this section for now.

To get started using tiered storage offloaders, you need to download the offloaders tarball release on every broker node in one of the following ways:

* by clicking the link below and downloading the release from an Apache mirror:

  * <a href="pulsar:offloader_release_url" download>Pulsar Tiered Storage Offloaders {{pulsar:version}} release</a>

* from the Pulsar [downloads page](pulsar:download_page_url)
* from the Pulsar [releases page](https://github.com/apache/pulsar/releases/latest)
* using [wget](https://www.gnu.org/software/wget):

  ```shell
  $ wget pulsar:offloader_release_url
  ```

Once you download the tarball, in the pulsar directory, untar the offloaders package and copy the offloaders as `offloaders` in the pulsar directory:

```bash
$ tar xvfz apache-pulsar-offloaders-{{pulsar:version}}-bin.tar.gz

// you can find a directory named `apache-pulsar-offloaders-{{pulsar:version}}` in the pulsar directory
// then copy the offloaders

$ mv apache-pulsar-offloaders-{{pulsar:version}}/offloaders offloaders

$ ls offloaders
tiered-storage-jcloud-{{pulsar:version}}.nar
```

For more details of how to configure tiered storage feature, you can refer to the [Tiered storage cookbook](cookbooks-tiered-storage.md)


## Deploy a ZooKeeper cluster

> If you already have an exsiting zookeeper cluster and want to use it, you can skip this section.

[ZooKeeper](https://zookeeper.apache.org) manages a variety of essential coordination- and configuration-related tasks for Pulsar. To deploy a Pulsar cluster you need to deploy ZooKeeper first (before all other components). You had better deploy a 3-node ZooKeeper cluster. Pulsar does not make heavy use of ZooKeeper, so more lightweight machines or VMs should suffice for running ZooKeeper.

To begin, add all ZooKeeper servers to the configuration specified in [`conf/zookeeper.conf`](reference-configuration.md#zookeeper) (in the Pulsar directory that you create [above](#install-the-pulsar-binary-package)). The following is an example:

```properties
server.1=zk1.us-west.example.com:2888:3888
server.2=zk2.us-west.example.com:2888:3888
server.3=zk3.us-west.example.com:2888:3888
```

> If you have only one machine to deploy Pulsar, you just need to add one server entry in the configuration file.

On each host, you need to specify the ID of the node in the `myid` file of each node, which is in each `data/zookeeper` folder of server by default (you can change the file location via the [`dataDir`](reference-configuration.md#zookeeper-dataDir) parameter).

> See the [Multi-server setup guide](https://zookeeper.apache.org/doc/r3.4.10/zookeeperAdmin.html#sc_zkMulitServerSetup) in the ZooKeeper documentation for detailed information on `myid` and more.

On a ZooKeeper server at `zk1.us-west.example.com`, for example, you can set the `myid` value like this:

```bash
$ mkdir -p data/zookeeper
$ echo 1 > data/zookeeper/myid
```

On `zk2.us-west.example.com` the command is `echo 2 > data/zookeeper/myid` and so on.

Once you add each server to the `zookeeper.conf` configuration and have the appropriate `myid` entry, you can start ZooKeeper on all hosts (in the background, using nohup) with the [`pulsar-daemon`](reference-cli-tools.md#pulsar-daemon) CLI tool:

```bash
$ bin/pulsar-daemon start zookeeper
```

> If you plan to deploy zookeeper with bookie on the same node, you
> need to start zookeeper by using different stats port.

Start zookeeper with [`pulsar-daemon`](reference-cli-tools.md#pulsar-daemon) CLI tool like:

```bash
$ PULSAR_EXTRA_OPTS="-Dstats_server_port=8001" bin/pulsar-daemon start zookeeper
```

## Initialize cluster metadata

Once you deploy ZooKeeper for your cluster, you need to write some metadata to ZooKeeper for each cluster in your instance. You only need to write **once**.

You can initialize this metadata using the [`initialize-cluster-metadata`](reference-cli-tools.md#pulsar-initialize-cluster-metadata) command of the [`pulsar`](reference-cli-tools.md#pulsar) CLI tool. This command can be run on any machine in your ZooKeeper cluster. The following is an example:

```shell
$ bin/pulsar initialize-cluster-metadata \
  --cluster pulsar-cluster-1 \
  --zookeeper zk1.us-west.example.com:2181 \
  --configuration-store zk1.us-west.example.com:2181 \
  --web-service-url http://pulsar.us-west.example.com:8080 \
  --web-service-url-tls https://pulsar.us-west.example.com:8443 \
  --broker-service-url pulsar://pulsar.us-west.example.com:6650 \
  --broker-service-url-tls pulsar+ssl://pulsar.us-west.example.com:6651
```

As you can see from the example above, you
need to specify the following:

Flag | Description
:----|:-----------
`--cluster` | A name for the cluster
`--zookeeper` | A "local" ZooKeeper connection string for the cluster. This connection string only needs to include *one* machine in the ZooKeeper cluster.
`--configuration-store` | The configuration store connection string for the entire instance. As with the `--zookeeper` flag, this connection string only needs to include *one* machine in the ZooKeeper cluster.
`--web-service-url` | The web service URL for the cluster, plus a port. This URL should be a standard DNS name. The default port is 8080 (you had better not use a different port).
`--web-service-url-tls` | If you use [TLS](security-tls-transport.md), you also need to specify a TLS web service URL for the cluster. The default port is 8443 (you had better not use a different port).
`--broker-service-url` | A broker service URL enabling interaction with the brokers in the cluster. This URL should not use the same DNS name as the web service URL but should use the `pulsar` scheme instead. The default port is 6650 (you had better not use a different port).
`--broker-service-url-tls` | If you use [TLS](security-tls-transport.md), you also need to specify a TLS web service URL for the cluster as well as a TLS broker service URL for the brokers in the cluster. The default port is 6651 (you had better not use a different port).


> If you don't have a DNS server, you can use multi-host in service URL with the following settings:
>
> ```properties
> --web-service-url http://host1:8080,host2:8080,host3:8080 \
> --web-service-url-tls https://host1:8443,host2:8443,host3:8443 \
> --broker-service-url pulsar://host1:6650,host2:6650,host3:6650 \
> --broker-service-url-tls pulsar+ssl://host1:6651,host2:6651,host3:6651
> ```

## Deploy a BookKeeper cluster

[BookKeeper](https://bookkeeper.apache.org) handles all persistent data storage in Pulsar. You need to deploy a cluster of BookKeeper bookies to use Pulsar. You can choose to run a **3-bookie BookKeeper cluster**.

You can configure BookKeeper bookies using the [`conf/bookkeeper.conf`](reference-configuration.md#bookkeeper) configuration file. The most important step in configuring bookies for our purposes here is ensuring that the [`zkServers`](reference-configuration.md#bookkeeper-zkServers) is set to the connection string for the ZooKeeper cluster. The following is an example:

```properties
zkServers=zk1.us-west.example.com:2181,zk2.us-west.example.com:2181,zk3.us-west.example.com:2181
```

Once you appropriately modify the `zkServers` parameter, you can provide any other configuration modifications you need. You can find a full listing of the available BookKeeper configuration parameters [here](reference-configuration.md#bookkeeper), although consulting the [BookKeeper documentation](http://bookkeeper.apache.org/docs/latest/reference/config/) for a more in-depth guide might be a better choice.

> ##### NOTES
>
> Since Pulsar 2.1.0 releases, Pulsar introduces [stateful function](functions-develop.md#state-storage) for Pulsar Functions. If you want to enable that feature,
> you need to enable table service on BookKeeper by doing the following setting in `conf/bookkeeper.conf` file.
>
> ```conf
> extraServerComponents=org.apache.bookkeeper.stream.server.StreamStorageLifecycleComponent
> ```

Once you apply the desired configuration in `conf/bookkeeper.conf`, you can start up a bookie on each of your BookKeeper hosts. You can start up each bookie either in the background, using [nohup](https://en.wikipedia.org/wiki/Nohup), or in the foreground.

To start the bookie in the background, use the [`pulsar-daemon`](reference-cli-tools.md#pulsar-daemon) CLI tool:

```bash
$ bin/pulsar-daemon start bookie
```

To start the bookie in the foreground:

```bash
$ bin/bookkeeper bookie
```

You can verify that a bookie works properly by running the `bookiesanity` command for the [BookKeeper shell](reference-cli-tools.md#shell) on it:

```bash
$ bin/bookkeeper shell bookiesanity
```

This command creates an ephemeral BookKeeper ledger on the local bookie, writes a few entries, reads them back, and finally deletes the ledger.

After you start all the bookies, you can use `simpletest` command for [BookKeeper shell](reference-cli-tools.md#shell) on any bookie node, to
verify all the bookies in the cluster are up running.

```bash
$ bin/bookkeeper shell simpletest --ensemble <num-bookies> --writeQuorum <num-bookies> --ackQuorum <num-bookies> --numEntries <num-entries>
```

This command creates a `num-bookies` sized ledger on the cluster, writes a few entries, and finally deletes the ledger.


## Deploy Pulsar brokers

Pulsar brokers are the last thing you need to deploy in your Pulsar cluster. Brokers handle Pulsar messages and provide the administrative interface of Pulsar. A good choice is to run **3 brokers**, one for each machine that already runs a BookKeeper bookie.

### Configure Brokers

The most important element of broker configuration is ensuring that each broker is aware of the ZooKeeper cluster that you have deployed. Make sure that the [`zookeeperServers`](reference-configuration.md#broker-zookeeperServers) and [`configurationStoreServers`](reference-configuration.md#broker-configurationStoreServers) parameters. In this case, since you only have 1 cluster and no configuration store setup, the `configurationStoreServers` point to the same `zookeeperServers`.

```properties
zookeeperServers=zk1.us-west.example.com:2181,zk2.us-west.example.com:2181,zk3.us-west.example.com:2181
configurationStoreServers=zk1.us-west.example.com:2181,zk2.us-west.example.com:2181,zk3.us-west.example.com:2181
```

You also need to specify the cluster name (matching the name that you provide when you [initialize the metadata of the cluster](#initialize-cluster-metadata)):

```properties
clusterName=pulsar-cluster-1
```

In addition, you need to match the broker and web service ports provided when you initialize the metadata of the cluster (especially when you use a different port from default):

```properties
brokerServicePort=6650
brokerServicePortTls=6651
webServicePort=8080
webServicePortTls=8443
```

> If you deploy Pulsar in a one-node cluster, you should update the replication settings in `conf/broker.conf` to `1`
>
> ```properties
> # Number of bookies to use when creating a ledger
> managedLedgerDefaultEnsembleSize=1
>
> # Number of copies to store for each message
> managedLedgerDefaultWriteQuorum=1
> 
> # Number of guaranteed copies (acks to wait before write is complete)
> managedLedgerDefaultAckQuorum=1
> ```

### Enable Pulsar Functions (optional)

If you want to enable [Pulsar Functions](functions-overview.md), you can follow the instructions as below:

1. Edit `conf/broker.conf` to enable functions worker, by setting `functionsWorkerEnabled` to `true`.

    ```conf
    functionsWorkerEnabled=true
    ```

2. Edit `conf/functions_worker.yml` and set `pulsarFunctionsCluster` to the cluster name that you provide when you [initialize the metadata of the cluster](#initialize-cluster-metadata). 

    ```conf
    pulsarFunctionsCluster: pulsar-cluster-1
    ```

If you want to learn more options about deploying functions worker, checkout [Deploy and manage functions worker](functions-worker.md).

### Start Brokers

You can then provide any other configuration changes that you want in the [`conf/broker.conf`](reference-configuration.md#broker) file. Once you decide on a configuration, you can start up the brokers for your Pulsar cluster. Like ZooKeeper and BookKeeper, you can start brokers either in the foreground or in the background, using nohup.

You can start a broker in the foreground using the [`pulsar broker`](reference-cli-tools.md#pulsar-broker) command:

```bash
$ bin/pulsar broker
```

You can start a broker in the background using the [`pulsar-daemon`](reference-cli-tools.md#pulsar-daemon) CLI tool:

```bash
$ bin/pulsar-daemon start broker
```

Once you succesfully start up all the brokers that you intend to use, your Pulsar cluster should be ready to go!

## Connect to the running cluster

Once your Pulsar cluster is up and running, you should be able to connect with it using Pulsar clients. One such client is the [`pulsar-client`](reference-cli-tools.md#pulsar-client) tool, which is included with the Pulsar binary package. The `pulsar-client` tool can publish messages to and consume messages from Pulsar topics and thus provide a simple way to make sure that your cluster runs properly.

To use the `pulsar-client` tool, first modify the client configuration file in [`conf/client.conf`](reference-configuration.md#client) in your binary package. You need to change the values for `webServiceUrl` and `brokerServiceUrl`, substituting `localhost` (which is the default), with the DNS name that you assign to your broker/bookie hosts. The following is an example:

```properties
webServiceUrl=http://us-west.example.com:8080
brokerServiceurl=pulsar://us-west.example.com:6650
```

> If you don't have a DNS server, you can specify multi-host in service URL like below:
>
> ```properties
> webServiceUrl=http://host1:8080,host2:8080,host3:8080
> brokerServiceurl=pulsar://host1:6650,host2:6650,host3:6650
> ```

Once you do that, you can publish a message to Pulsar topic:

```bash
$ bin/pulsar-client produce \
  persistent://public/default/test \
  -n 1 \
  -m "Hello Pulsar"
```

> You may need to use a different cluster name in the topic if you specify a cluster name different from `pulsar-cluster-1`.

This command publishes a single message to the Pulsar topic. In addition, you can subscribe the Pulsar topic in a different terminal before publishing messages as below:

```bash
$ bin/pulsar-client consume \
  persistent://public/default/test \
  -n 100 \
  -s "consumer-test" \
  -t "Exclusive"
```

Once you successfully publish the message above to the topic, you should see it in the standard output:

```bash
----- got message -----
Hello Pulsar
```

## Run Functions

> If you have [enabled](#enable-pulsar-functions-optional) Pulsar Functions, you can also tryout pulsar functions now.

Create a ExclamationFunction `exclamation`.

```bash
bin/pulsar-admin functions create \
  --jar examples/api-examples.jar \
  --classname org.apache.pulsar.functions.api.examples.ExclamationFunction \
  --inputs persistent://public/default/exclamation-input \
  --output persistent://public/default/exclamation-output \
  --tenant public \
  --namespace default \
  --name exclamation
```

Check if the function runs as expected by [triggering](functions-deploying.md#triggering-pulsar-functions) the function.

```bash
bin/pulsar-admin functions trigger --name exclamation --trigger-value "hello world"
```

You can see the output as below:

```shell
hello world!
```
