Multiple Exporters

Rotel can be configured to support exporting to multiple destinations across multiple exporter types.

The following additional configuration parameters set up support for multiple exporters. Similar to the options above, all CLI arguments can be passed as environment variables as well. It is not possible to set --exporter and --exporters at the same time.

Option	Default	Options
--exporters		name:type pairs, comma-separated
--exporters-traces		exporter name
--exporters-metrics		exporter name
--exporters-logs		exporter name
--exporters-internal-metrics		exporter name

First start by defining the set of exporters that you would like to use, optionally specifying a custom name for them to differentiate their configuration options. For example, to export logs and metrics to two separate Clickhouse nodes while exporting traces to Datadog, we'll use the following --exporters argument (or ROTEL_EXPORTERS envvar):

--exporters logging:clickhouse,stats:clickhouse,datadog

The argument form of --exporters takes name:type pairs separated by commas, where the first part is a custom name and the second part is the type of exporter. You can exclude the name if there is a single exporter by that name, which means the name is the same as the exporter type.

Next you must set environment variables in the form ROTEL_EXPORTER_{NAME}_{PARAMETER} to configure the multiple exporters. These variable names are dynamic and use the custom name to differentiate settings for similar exporter types. These must be specified by environment variables, there are no CLI argument alternatives for them. The {PARAMETER} fields match the configuration options for the given exporter type.

Using our example above, the user must set, at a minimum, the following environment variables. (For Clickhouse Cloud you would need to include a username/password, but we are skipping those for brevity.)

• ROTEL_EXPORTER_LOGGING_ENDPOINT=https://xxxxxxx.us-east-1.aws.clickhouse.cloud:8443
• ROTEL_EXPORTER_STATS_ENDPOINT=https://xxxxxxx.us-west-1.aws.clickhouse.cloud:8443
• ROTEL_EXPORTER_DATADOG_API_KEY=dd-abcd1234

Lastly, the user would need to connect these exporters to the telemetry types. Using the requirements above, the user would specify the following:

--exporters-traces datadog --exporters-metrics stats --exporters-logs logging

Alternatively, the following environment variables would do the same:

• ROTEL_EXPORTERS_TRACES=datadog
• ROTEL_EXPORTERS_METRICS=stats
• ROTEL_EXPORTERS_LOGS=logging

That's it, Rotel will now export logs and metrics to different Clickhouse Cloud endpoints while sending traces to Datadog.

You can send telemetry to multiple exporters by listing multiple comma-separated in the exporters configuration. Telemetry is sent sequentially to the sending queues for each exporter in-order. That means if one exporter is generating back pressure it may impact the other exporters.

For example, to send logs to both the stats and logging clickhouse exporters, you would instead set the ROTEL_EXPORTERS_LOGS environment variable to:

• ROTEL_EXPORTERS_LOGS=stats,logging

note

Sending telemetry to multiple exporters at once is currently in alpha. The telemetry is copied between the multiple exporter queues which may cause additional memory use under large volumes. This is an area of improvement as we expand on this capability.

The Python Lamba + Clickhouse Example includes an example of multiple exporter configuration.