influxdb-cxx

The library exports the target InfluxData::InfluxDB. You can include it either via find_package or by adding the source as a subdirectory.

Using find_package:

project(example)

find_package(InfluxDB)

add_executable(example-influx main.cpp)
target_link_libraries(example-influx PRIVATE InfluxData::InfluxDB)

Using add_subdirectory:

project(example)
add_subdirectory(influxdb-cxx)
add_executable(example-influx main.cpp)
target_link_libraries(example-influx PRIVATE InfluxData::InfluxDB)

To install the library from source, ensure you have CMake 3.12+ and a C++20 compatible compiler. You must have cpr installed (which requires CMake support). boost 1.90+ is optional and only required if you intend to use TCP, UDP, or Unix socket transports.

Run the following commands to build and install:

mkdir build && cd build
cmake ..
sudo make install

To improve performance, you can enable batching using batchOf(size). This buffers points and writes them in chunks of the specified size.

Important: When batch writing is enabled, you must call flushBatch() to ensure all pending points are written to the server, especially before the client object is destroyed.

auto influxdb = influxdb::InfluxDBFactory::Get("http://localhost:8086?db=test");
// Write batches of 100 points
influxdb->batchOf(100);

for (;;) {
  influxdb->write(influxdb::Point{"test"}.addField("value", 10));
}

// Ensure all points are written
influxdb->flushBatch();

Use influxdb::InfluxDBFactory::Get with a complete URI to create a client, then use the write method with an influxdb::Point object to send data.

// Provide complete URI
auto influxdb = influxdb::InfluxDBFactory::Get("http://localhost:8086?db=test");
influxdb->write(influxdb::Point{"test"}
  .addField("value", 10)
  .addTag("host", "localhost")
);

Queries are available over HTTP only. Use the query method and pass an IFQL string to receive a std::vector<influxdb::Point>.

// Available over HTTP only
auto influxdb = influxdb::InfluxDBFactory::Get("http://localhost:8086?db=test");
/// Pass an IFQL to get list of points
std::vector<influxdb::Point> points = influxdb->query("SELECT * FROM test");

Use the execute method to run commands (like SHOW DATABASES) and receive the response.

auto influxdb = influxdb::InfluxDBFactory::Get("http://localhost:8086?db=test");

// Execute a command and receive it's response
const auto response = influxdb->execute("SHOW DATABASES");

For advanced HTTP configuration, use the InfluxDBBuilder::http fluent interface instead of the factory. This allows setting timeouts and authentication tokens.

auto influxdb = InfluxDBBuilder::http("http://localhost:8086?db=test")
                    .setTimeout(std::chrono::seconds{20})
                    .setAuthToken("<token>")
                    .connect();

The transport type is determined by the protocol in the URI. Note that boost is required for TCP, UDP, and Unix socket transports, and is also required to support queries when using those transports.

URI Formats:

• Standard: [protocol]://[username:password@]host:port[?db=database]
• Auth token: [protocol]://[token@]host:port[?db=database]

The HTTP transport supports two primary authentication methods for InfluxDB:

1. Basic Authentication: Use setBasicAuthentication(user, pass) to provide a username and password.
2. API Token: Use setAuthToken(token) to provide a Bearer token for authentication.

Both methods are used to authorize requests sent by the transport.

// Using Basic Auth
transport.setBasicAuthentication("my_user", "my_password");

// Using API Token
transport.setAuthToken("my_secret_token");

The influxdb::transports::TCP class provides a transport implementation for sending data to InfluxDB over a TCP connection. It requires a hostname and a port to initialize the connection.

Key methods:

• send(std::string&& message): Sends a raw message (blob) via the established TCP connection.
• is_connected(): Returns true if the socket is currently connected.
• reconnect(): Attempts to reconnect the socket to the endpoint.

#include <influxdb/transports/TCP.h>

// Initialize TCP transport with hostname and port
influxdb::transports::TCP transport("localhost", 8086);

// Send a message
transport.send("your_influxdb_line_protocol_data");

// Check connection status
if (transport.is_connected()) {
    // ...
}

// Reconnect if necessary
transport.reconnect();