Configuration Options

Configuration for Relay is recorded in the file .relay/config.yml. To change this location, pass the --config option to any Relay command:

❯ ./relay run --config /path/to/folder

All configuration keys are snake_case.

Relay

The following document the general settings for Relay:

relay.mode

String, default: managed, possible values: managed, static, proxy and capture

Controls how Relay obtains the project configuration for events. For detailed explanation of these modes, see Relay Modes.

relay.upstream

String, default: https://sentry.io

Fully qualified URL of the upstream Relay or Sentry instance.

relay.host

String, default: 0.0.0.0 in Docker, otherwise 127.0.0.1

The host to which Relay should bind (network interface). Example: 0.0.0.0

relay.port

Integer, default: 3000

The port to bind for the unencrypted Relay HTTP server. Example: 3000

relay.tls_port

Integer, optional

Optional port to bind for the encrypted Relay HTTPS server. Example: 3001

This is in addition to the port option: If you set up a HTTPS server at tls_port, the HTTP server at port still exists.

relay.tls_identity_path

String, optional

The filesystem path to the identity (DER-encoded PKCS12) to use for the HTTPS server. Relative paths are evaluated in the current working directory. Example: relay_dev.pfx

relay.tls_identity_password

String, optional

Password for the PKCS12 archive in relay.tls_identity_path.

relay.override_project_ids

Boolean, optional

Overrides project identifiers stated in client DSNs with the identifier used at the Sentry upstream. By default, Relay rejects data on project ID mismatch.

Set this setting to true when Relay redirects traffic to a migrated Sentry instance, such as when moving from self-hosted to Sentry

HTTP

These settings control the network-related configuration.

http.timeout

Integer, default: 5

Timeout for upstream requests in seconds.

This timeout covers the time from sending the request until receiving response headers. Neither the connection process and handshakes, nor reading the response body is covered in this timeout.

http.connection_timeout

Integer, default: 3

Timeout for establishing connections with the upstream in seconds.

This includes SSL handshakes. Relay reuses connections when the upstream supports connection keep-alive. Connections are retained for a maximum 75 seconds, or 15 seconds of inactivity.

http.max_retry_interval

Integer, default: 60

Maximum interval between failed request retries in seconds.

http.host_header

String, default: null

The custom HTTP Host header to be sent to the upstream.

Caching

These settings fine tune caching of project states.

cache.project_expiry

Integer, default: 300 (5 minutes)

The cache timeout for project configurations in seconds. Irrelevant if you use the "simple proxy mode", where your project config is stored in local files.

cache.project_grace_period

Integer, default: 0 (seconds)

Number of seconds to continue using this project configuration after cache expiry while a new state is being fetched. This is added on top of cache.project_expiry and cache.miss_expiry.

cache.relay_expiry

Integer, default: 3600 (1 hour)

The cache timeout for downstream Relay info (public keys) in seconds. This is only relevant if you plan to connect further Relays to this one.

cache.envelope_expiry

Integer, default: 600 (10 minutes)

The maximum time Relay buffers incoming payloads in its cache in the case of network issues or backlogs. This applies to all types of data sent to Relay, including events, attachments, and sessions.

See also cache.envelope_buffer_size.

cache.miss_expiry

Integer, default: 60 (1 minute)

The cache timeout for non-existing entries.

cache.batch_interval

Integer, default: 100 (100 milliseconds)

The buffer timeout for batched queries before sending them upstream in milliseconds.

cache.batch_size

Integer, default: 500

The maximum number of project configs to fetch from Sentry at once.

cache.file_interval

Integer, default: 10 (10 seconds)

Interval for watching local cache override files in seconds.

cache.envelope_buffer_size

Integer, default: 1000

The maximum number of incoming payloads that are buffered in the case of network issues or backlogs. This applies to all types of data sent to Relay, including events, attachments, and sessions.

See also cache.envelope_expiry.

cache.eviction_interval

Integer, default: 60 (seconds)

Interval for evicting outdated project configs from memory.

Spooling

These settings control on-disk spooling. Currently, only spooling for incoming envelopes is supported.

spool.envelopes.path

String, default: null

The path to the spool file, which is used to save the envelopes to disk. If provided, enables on-disk spooling.

spool.envelopes.max_memory_size

String, default: 500MB

The maximum in-memory buffer for incoming envelopes. The buffer will be spooled to disk when the configured size is reached.

spool.envelopes.max_disk_size

String, default: 500MB

The maximum size on-disk spool.

spool.envelopes.max_connections

Integer, default: 20

The maximum number of connections in the pool to manage the on-disk spool.

spool.envelopes.min_connections

Integer, default: 10

The minimum number of connections in the pool to manage the on-disk spool.

Size Limits

These settings control HTTP-related limits. All values are either integers, or are human-readable strings of a number and a human-readable unit, such as:

• 500B
• 1kB (1,000 bytes)
• 1KB or 1KiB (1,024 bytes)
• 1MB (1,000,000 bytes)
• 1MiB (1,048,576 bytes)

limits.max_concurrent_requests

Integer, default: 100

The maximum number of concurrent connections upstream. If supported by the upstream, Relay supports connection keepalive.

limits.max_concurrent_queries

Integer, default: 5

The maximum number of queries that can be sent concurrently from Relay upstream before Relay starts buffering requests. Queries are all requests made upstream for obtaining information and explicitly exclude event submission.

The concurrency of queries is additionally constrained by max_concurrent_requests.

limits.max_event_size

String, default: 1MiB

The maximum payload size for events.

limits.max_attachment_size

String, default: 50MiB

The maximum size for each attachment.

limits.max_attachments_size

String, default: 50MiB

The maximum combined size for all attachments in an envelope or request.

limits.max_envelope_size

String, default: 50MiB

The maximum payload size for an entire envelopes. Individual limits still apply.

limits.max_session_count

Integer, default: 100

The maximum number of session items per envelope.

limits.max_api_payload_size

String, default: 20MiB

The maximum payload size for general API requests.

limits.max_api_file_upload_size

String, default: 40MiB

The maximum payload size for file uploads and chunks.

limits.max_api_chunk_upload_size

String, default: 100MiB

The maximum payload size for chunks.

limits.max_thread_count

Integer, default: number of cpus

The maximum number of threads to spawn for each CPU and web worker.

The total number of threads spawned will roughly be 2 * limits.max_thread_count + N, where N is a fixed set of management threads.

limits.query_timeout

Integer, default: 30 (seconds)

The maximum number of seconds a query is allowed to take across retries. Individual requests have lower timeouts.

limits.max_connection_rate

Integer, default: 256

The maximum number of connections to Relay that can be created at once.

limits.max_pending_connections

Integer, default: 2048

The maximum number of pending connects to Relay. This corresponds to the backlog param of listen(2) in POSIX.

limits.max_connections

Integer: default: 25_000

The maximum number of open incoming connections to Relay.

limits.shutdown_timeout

Integer, default:L 10 (seconds)

The maximum number of seconds to wait for pending events after receiving a shutdown signal.

Logging

logging.level

String, default: info

The log level for the relay. One of:

• off
• error
• warn
• info
• debug
• trace

logging.log_failed_payloads

boolean, default: false

Logs full event payloads of failed events to the log stream.

logging.format

String, default: auto

Controls the log format. One of:

• auto: Auto detect (pretty for TTY, simplified for other)
• pretty: Human readable format with colors
• simplified: Simplified human readable log output
• json: JSON records, suitable for logging software

logging.enable_backtraces

boolean, default: true

Writes back traces for all internal errors to the log stream and includes them in Sentry errors, if enabled.

StatsD Metrics

metrics.statsd

String, optional

If set to a host/port string then metrics will be reported to this StatsD instance.

metrics.prefix

String, default: sentry.relay

The prefix that should be added to all metrics.

metrics.default_tags

Map of strings to strings, default: empty

A set of default tags that should be attached to all outgoing StatsD metrics.

metrics.hostname_tag

String, optional

If set, adds a tag of the given name and sets it to the hostname of the machine that is running Relay. This configuration is useful to distinguish multiple Relays.

metrics.buffering

boolean, default: true

Whether the emitted metrics will be buffered before sending to StatsD server. This generally improves performance, but comes with a caveat that with low traffic volume, metrics might take a few more seconds to propagate.

metrics.sample_rate

Float, default 1.0

Global sample rate for all emitted metrics. Should be between 0.0 and 1.0. If outside that range, the value will be normalized (negative values would become 0.0, positive larger than 1.0 become 1.0). For instance, the value of 0.3 means that only 30% of the emitted metrics will be sent. Note that the implemented sampling approach is not aware of metrics types, and, for example, does not rescale counter values when the sample rate is less than 1.0.

Internal Error Reporting

Configures error reporting for errors happening within Relay. Disabled by default.

sentry.enabled

boolean, default: false

Whether to report internal errors to a separate DSN. false means no internal errors are sent, but still logged.

sentry.dsn

String, optional

Sentry DSN to which to report internal Relay failures.

We recommend setting this to a value that will not send Relay errors to itself. Ideally, this value should send errors to Sentry directly, not another Relay.