Pulsar C++ client
You can use a Pulsar C++ client to create producers, consumers, and readers.
All the methods in producer, consumer, and reader of a C++ client are thread-safe. You can read the API docs for the C++ client.
Installation​
Use one of the following methods to install a Pulsar C++ client.
Brew​
Use Homebrew to install the latest tagged version with the library and headers:
brew install libpulsar
Deb​
- Download any one of the Deb packages:
- client
- client-devel
wget https://archive.apache.org/dist/pulsar/pulsar-2.8.4/DEB/apache-pulsar-client.deb
This package contains shared libraries libpulsar.so
and libpulsarnossl.so
.
wget https://archive.apache.org/dist/pulsar/pulsar-2.8.4/DEB/apache-pulsar-client-dev.deb
This package contains static libraries: libpulsar.a
, libpulsarwithdeps.a
and C/C++ headers.
- Install the package using the following command:
apt install ./apache-pulsar-client*.deb
Now, you can see Pulsar C++ client libraries installed under the /usr/lib
directory.
RPM​
- Download any one of the RPM packages:
- client
- client-debuginfo
- client-devel
wget https://archive.apache.org/dist/pulsar/pulsar-2.8.4/RPMS/apache-pulsar-client-2.8.4-1.x86_64.rpm
This package contains shared libraries: libpulsar.so
and libpulsarnossl.so
.
wget https://archive.apache.org/dist/pulsar/pulsar-2.8.4/RPMS/apache-pulsar-client-debuginfo-2.8.4-1.x86_64.rpm
This package contains debug symbols for libpulsar.so
.
wget https://archive.apache.org/dist/pulsar/pulsar-2.8.4/RPMS/apache-pulsar-client-devel-2.8.4-1.x86_64.rpm
This package contains static libraries: libpulsar.a
, libpulsarwithdeps.a
and C/C++ headers.
- Install the package using the following command:
rpm -ivh apache-pulsar-client*.rpm
Now, you can see Pulsar C++ client libraries installed under the /usr/lib
directory.
If you get an error like "libpulsar.so: cannot open shared object file: No such file or directory" when starting a Pulsar client, you need to run ldconfig
first.
Source​
For how to build Pulsar C++ client on different platforms from source code, see compliation.
Connection URLs​
To connect Pulsar using client libraries, you need to specify a Pulsar protocol URL.
Pulsar protocol URLs are assigned to specific clusters, you can use the Pulsar URI scheme. The default port is 6650
. The following is an example of localhost.
pulsar://localhost:6650
In a Pulsar cluster in production, the URL looks as follows.
pulsar://pulsar.us-west.example.com:6650
If you use TLS authentication, you need to add ssl
, and the default port is 6651
. The following is an example.
pulsar+ssl://pulsar.us-west.example.com:6651
Create a consumer​
To use Pulsar as a consumer, you need to create a consumer on the C++ client. The following is an example.
Client client("pulsar://localhost:6650");
Consumer consumer;
Result result = client.subscribe("my-topic", "my-subscription-name", consumer);
if (result != ResultOk) {
LOG_ERROR("Failed to subscribe: " << result);
return -1;
}
Message msg;
while (true) {
consumer.receive(msg);
LOG_INFO("Received: " << msg
<< " with payload '" << msg.getDataAsString() << "'");
consumer.acknowledge(msg);
}
client.close();
Create a producer​
To use Pulsar as a producer, you need to create a producer on the C++ client. The following is an example.
Client client("pulsar://localhost:6650");
Producer producer;
Result result = client.createProducer("my-topic", producer);
if (result != ResultOk) {
LOG_ERROR("Error creating producer: " << result);
return -1;
}
// Publish 10 messages to the topic
for (int i = 0; i < 10; i++){
Message msg = MessageBuilder().setContent("my-message").build();
Result res = producer.send(msg);
LOG_INFO("Message sent: " << res);
}
client.close();
Enable authentication in connection URLs​
If you use TLS authentication when connecting to Pulsar, you need to add ssl
in the connection URLs, and the default port is 6651
. The following is an example.
ClientConfiguration config = ClientConfiguration();
config.setUseTls(true);
config.setTlsTrustCertsFilePath("/path/to/cacert.pem");
config.setTlsAllowInsecureConnection(false);
config.setAuth(pulsar::AuthTls::create(
"/path/to/client-cert.pem", "/path/to/client-key.pem"););
Client client("pulsar+ssl://my-broker.com:6651", config);
For complete examples, refer to C++ client examples.
Schema​
This section describes some examples about schema. For more information about schema, see Pulsar schema.
Create producer with Avro schema​
The following example shows how to create a producer with an Avro schema.
static const std::string exampleSchema =
"{\"type\":\"record\",\"name\":\"Example\",\"namespace\":\"test\","
"\"fields\":[{\"name\":\"a\",\"type\":\"int\"},{\"name\":\"b\",\"type\":\"int\"}]}";
Producer producer;
ProducerConfiguration producerConf;
producerConf.setSchema(SchemaInfo(AVRO, "Avro", exampleSchema));
client.createProducer("topic-avro", producerConf, producer);
Create consumer with Avro schema​
The following example shows how to create a consumer with an Avro schema.
static const std::string exampleSchema =
"{\"type\":\"record\",\"name\":\"Example\",\"namespace\":\"test\","
"\"fields\":[{\"name\":\"a\",\"type\":\"int\"},{\"name\":\"b\",\"type\":\"int\"}]}";
ConsumerConfiguration consumerConf;
Consumer consumer;
consumerConf.setSchema(SchemaInfo(AVRO, "Avro", exampleSchema));
client.subscribe("topic-avro", "sub-2", consumerConf, consumer)