Set Up Performance
Learn how to enable performance monitoring in your app if it is not already set up.
With performance monitoring, Sentry tracks your software performance, measuring metrics like throughput and latency, and displaying the impact of errors across multiple systems. Sentry captures distributed traces consisting of transactions and spans, which measure individual services and individual operations within those services. Learn more about our model in Distributed Tracing.
If you’re adopting Performance in a high-throughput environment, we recommend testing prior to deployment to ensure that your service’s performance characteristics maintain expectations.
First, enable tracing and configure the sampling rate for transactions. Set the sample rate for your transactions by either:
- Setting a uniform sample rate for all transactions using the
traces_sample_rate
option in your SDK config to a number between0
and1
. (For example, to send 20% of transactions, settraces_sample_rate
to0.2
.) - Controlling the sample rate based on the transaction itself and the context in which it's captured, by providing a function to the
traces_sampler
config option.
The two options are meant to be mutually exclusive. If you set both, traces_sampler
will take precedence.
config/packages/sentry.yaml
sentry:
options:
# Specify a fixed sample rate:
traces_sample_rate: 1.0
# Or provide a custom sampler:
traces_sampler: 'sentry.callback.traces_sampler'
# Only needed when using the `traces_sampler`
services:
sentry.callback.traces_sampler:
class: 'App\Service\Sentry'
factory: ['@App\Service\Sentry', 'getTracesSampler']
The service needed for the traces_sampler
option can be implemented as follows:
src/Service/Sentry.php
<?php
namespace App\Service;
class Sentry
{
public function getTracesSampler(): callable
{
return function(\Sentry\Tracing\SamplingContext $context): float {
// return a number between 0 and 1
};
}
}
Learn more in Callables in Symfony Options.
Learn more about performance monitoring options, how to use the traces_sampler function, or how to sample transactions.
While you're testing, set traces_sample_rate
to 1.0
, as that ensures that every transaction will be sent to Sentry.
Once testing is complete, you may want to set a lower traces_sample_rate
value, or switch to using traces_sampler
to selectively sample and filter your transactions, based on contextual data.
Response time is somewhat impacted when you use the performance capabilities in your PHP application, (depending on the traces_sample_rate
you've configured).
If your web server is using FastCGI, our SDK utilizes the kernel.terminate event, which means the response is sent to the user before the performance data is sent to Sentry.
If your web server isn't using FastCGI, you can run Relay locally on the same machine or a local network that can act as a proxy/agent.
Doing this will make the PHP process send requests to your local Relay, which will then forward them to Sentry, instead of sending requests to Sentry directly.
To begin using Relay, check out our docs for getting started. We recommend using Relay in managed
mode (which is the default).
Follow the instructions in the Relay docs to send a test event through Relay to Sentry. Don't forget to update your DSN
to point to your running Relay instance. After you set up Relay, you should see a dramatic improvement to the impact on your server.
Our documentation is open source and available on GitHub. Your contributions are welcome, whether fixing a typo (drat!) or suggesting an update ("yeah, this would be better").