Server Configuration

Many Seq options can be configured through the Settings section of the web user interface. Lower-level settings, especially those that control the HTTP endpoint, or require a restart to be applied, are stored in the Seq.json configuration file, and manipulated using the seq config command-line.

The seq config command-line

From an administrative command prompt on the Seq server, running seq config list will list the available settings and their values:

seq config list

Setting values can be changed with seq config set by specifying the setting name and value:

seq config set -k api.listenUris -v https://example.com,https://example.com:45341
seq config set -k cache.systemRamTarget -v 0.8
seq config clear -k storage.prefferedEngine
seq service restart

Settings that accept multiple values can be specified by listing values separated by a comma ,.

Values can be reset to their defaults using seq config clear and the setting name.

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Seq reads settings Seq.json at startup, so the Seq service must be restarted before changes will take effect.

Environment variable overrides

Each setting value can be overridden at runtime by specifying an environment variable of the form SEQ_<setting path>, where <setting path> contains one element for each dotted segment of the setting name, separated by underscores.

For example the setting api.listenUris can overridden with the SEQ_API_LISTENURIS variable.

Settings

Settings can be viewed and updated from the command-line using the seq config command. Settings also support overrides in environment variables. The matching environment variable name for each setting is shown in the detailed documentation below.

api.assumeHttps

If True, cookies will carry the secure attribute even when served over HTTP.

The value can be overridden using the SEQ_API_ASSUMEHTTPS environment variable.

api.avoidLdap

If True, the Windows local security authority will be used instead of LDAP in some features (experimental).

The value can be overridden using the SEQ_API_AVOIDLDAP environment variable.

api.canonicalUri

The address that the server can be accessed on externally.

The value can be overridden using the SEQ_API_CANONICALURI environment variable.

api.corsAllowedOrigins

Origins from which the full API will be accessible using CORS. Note that this is not necessary for ingestion - events can always be sent to the ingestion endpoint using CORS.

The value can be overridden using the SEQ_API_CORSALLOWEDORIGINS environment variable.

api.frameAllowFrom

Origins that may embed the Seq UI within an <iframe>.

The value can be overridden using the SEQ_API_FRAMEALLOWFROM environment variable.

api.hardSessionExpirySeconds

If non-null, this will override the various session expiry timeouts used by the different authentication providers. The initial value is null (no additional hard session expiry override).

The value can be overridden using the SEQ_API_HARDSESSIONEXPIRYSECONDS environment variable.

api.hstsIncludeSubDomains

The includeSubdomains field set in the HSTS header, if enabled.

The value can be overridden using the SEQ_API_HSTSINCLUDESUBDOMAINS environment variable.

api.hstsMaxAge

The max-age specified in the HSTS header in seconds, if enabled. The initial value is 31536000 (365 days).

The value can be overridden using the SEQ_API_HSTSMAXAGE environment variable.

api.idleSessionExpirySeconds

If non-null, this will set an expiry timeout that will revoke user sessions after a period of inactivity. The initial value is 172800 (48 hours).

The value can be overridden using the SEQ_API_IDLESESSIONEXPIRYSECONDS environment variable.

api.ingestionPort

If non-null, only event ingestion will be allowed on the specified port. Note that a corresponding entry must exist in api.listenUris.

The value can be overridden using the SEQ_API_INGESTIONPORT environment variable.

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Make sure that an entry for the port, including the protocol and hostname to listen on, is present in api.listenUris in addition to the ingestionPort setting.

api.integratedAuthenticationScheme

The authentication scheme used for Windows authentication. IntegratedWindowsAuthentication (the default) and Negotiate are supported.

The value can be overridden using the SEQ_API_INTEGRATEDAUTHENTICATIONSCHEME environment variable.

api.listenUris

The addresses that the server will listen on. The first entry listed will be used as the default when generating URIs for apps and notifications.

The value can be overridden using the SEQ_API_LISTENURIS environment variable.

api.redirectHttpToHttps

Whether to redirect HTTP requests to the first HTTPS endpoint listed in api.listenUris. If set to True, the HSTS header will also be set.

The value can be overridden using the SEQ_API_REDIRECTHTTPTOHTTPS environment variable.

cache.largeObjectHeapCompaction

Specify how the .NET large object heap is compacted. Allowed values are Periodic, Never, and Default (a version-specific value, currently equivalent to Periodic). Compaction can prevent out-of-memory errors in some circumstances, but may result in short availability pauses while compaction takes place.

The value can be overridden using the SEQ_CACHE_LARGEOBJECTHEAPCOMPACTION environment variable.

cache.systemRamTarget

Seq uses RAM heavily to speed up query processing. On shared machines (or local developer workstations) it may be desirable to limit this behavior. Specifying a smaller fractional value here (e.g. 0.5) will cause Seq to release memory once system memory usage surpasses the threshold (e.g. 50%). If the value specified is greater than 1.0, it will betreated as an absolute byte value. The value may be set to zero to completelydisable caching - this may have significant performance impact.

The value can be overridden using the SEQ_CACHE_SYSTEMRAMTARGET environment variable.

diagnostics.internalLoggingLevel

Seq's own internal logging level. Modifying this value may cause significantly higher I/O load and is not recommended. The default is Information.

The value can be overridden using the SEQ_DIAGNOSTICS_INTERNALLOGGINGLEVEL environment variable.

diagnostics.internalLogPath

The location for Seq's own internal log files.

The value can be overridden using the SEQ_DIAGNOSTICS_INTERNALLOGPATH environment variable.

diagnostics.internalLogServerUrl

Send Seq's internal logs to another Seq server.

The value can be overridden using the SEQ_DIAGNOSTICS_INTERNALLOGSERVERURL environment variable.

diagnostics.metricsSamplingIntervalSeconds

Interval (seconds) at which Seq will write metrics information to its internal log file.

The value can be overridden using the SEQ_DIAGNOSTICS_METRICSSAMPLINGINTERVALSECONDS environment variable.

diagnostics.nativeStorageMetricsSamplingIntervalMinutes

Interval (minutes) at which Seq will write native storage metrics to its internal log file.

The value can be overridden using the SEQ_DIAGNOSTICS_NATIVESTORAGEMETRICSSAMPLINGINTERVALMINUTES environment variable.

diagnostics.telemetryServerUrl

Send Seq's error telemetry (if enabled) to another Seq server.

The value can be overridden using the SEQ_DIAGNOSTICS_TELEMETRYSERVERURL environment variable.

firstRun.adminPasswordHash

A salted, cryptographically-hashed, base-64 encoded default password for the administrator account, ignored after the first time Seq is run. Use seq config hash to compute a value that can be stored in this setting. Alternatively, consider using the --default-admin-password-stdin argument to the seq run command. The default when no password is supplied is to not enable authentication.

The value can be overridden using the SEQ_FIRSTRUN_ADMINPASSWORDHASH environment variable.

firstRun.adminUsername

A default username for the administrator account, ignored after the first time Seq is run. The default is admin.

The value can be overridden using the SEQ_FIRSTRUN_ADMINUSERNAME environment variable.

firstRun.requireAuthenticationForHttpIngestion

If true, API keys or user authentication will be required for HTTP/S ingestion; ignored after thefirst time Seq is run.

The value can be overridden using the SEQ_FIRSTRUN_REQUIREAUTHENTICATIONFORHTTPINGESTION environment variable.

metastore.mSSql.connectionString

A connection string for the Microsoft SQL Server/Azure SQL instance into which metadata will be stored. If null,local metadata storage will be used. The default is null.

The value can be overridden using the SEQ_METASTORE_MSSQL_CONNECTIONSTRING environment variable.

metastore.mSSql.msiResource

If the connection must use an Azure Managed Service Identity, the resource for which to request an access token; normally this will be https://database.windows.net/; the default is to not use an Azure MSI.

The value can be overridden using the SEQ_METASTORE_MSSQL_MSIRESOURCE environment variable.

metastore.mSSql.msiTenantId

If using an Azure Managed Service Identity and the identity has access to multiple tenants, the tenant id; the default is to not specify a tenant id.

The value can be overridden using the SEQ_METASTORE_MSSQL_MSITENANTID environment variable.

metastore.mSSql.schema

The name of the schema under which Seq should store metadata. The default is dbo.

The value can be overridden using the SEQ_METASTORE_MSSQL_SCHEMA environment variable.

services.servicesBaseUri

The base URL Seq uses for service discovery, if enabled. The default is https://datalust.co.

The value can be overridden using the SEQ_SERVICES_SERVICESBASEURI environment variable.

storage.flare.diskReaderLimit

The maximum number of storage threads that will be allowed to concurrently read from the disk. Increasing this value can improve throughput, at the expense of additional risk of stampedes causingservice instability.

The value can be overridden using the SEQ_STORAGE_FLARE_DISKREADERLIMIT environment variable.

storage.flare.indexerPriority

The priority assigned to storage management and indexing; the default value 0 will cause all required management tasks to proceed normally. Higher values represent the fraction of maintenance time during which these tasks should yield.

The value can be overridden using the SEQ_STORAGE_FLARE_INDEXERPRIORITY environment variable.

storage.flare.queryParallelism

The default number of threads assigned to execution of each parallel query. Increasing this limit can result in higher service resource usage.

The value can be overridden using the SEQ_STORAGE_FLARE_QUERYPARALLELISM environment variable.

storage.masterKey

The master encryption key used to protect sensitive values in the Seq document store.

Windows: this value is itself encrypted and must be retrieved using the seq show-key command for secure backup.

Linux/macOS: this value is stored unencrypted in Seq.json; use the SEQ_STORAGE_MASTERKEY variable for secure key management.

The value can be overridden using the SEQ_STORAGE_MASTERKEY environment variable.

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On Windows, this value cannot be manipulated directly as DPAPI is used to protect the value stored in Seq.json. Use the seq.exe show-key command to retrieve the cleartext key for backup purposes.

storage.masterKeyEnvironmentVariableName

Obsolete; use the SEQ_STORAGE_MASTERKEY environment variable to supply the master encryption key.

The value can be overridden using the SEQ_STORAGE_MASTERKEYENVIRONMENTVARIABLENAME environment variable.

Seq.json Example

An example Seq.json configuration file is shown below.

{
  "cache": {
    "systemRamTarget": 0.9,
    "largeObjectHeapCompaction": "Default"
  },
  "diagnostics": {
    "internalLogPath": null,
    "internalLoggingLevel": "Information",
    "internalLogServerUrl": null,
    "telemetryServerUrl": null,
    "metricsSamplingIntervalSeconds": 300,
    "nativeStorageMetricsSamplingIntervalMinutes": 60
  },
  "api": {
    "listenUris": [
      "https://seq.example.com",
      "https://seq.example.com:45341"
    ],
    "canonicalUri": null,
    "ingestionPort": 45341,
    "corsAllowedOrigins": [],
    "frameAllowFrom": [],
    "integratedAuthenticationScheme": null,
    "avoidLdap": false,
    "assumeHttps": false,
    "redirectHttpToHttps": false,
    "hstsMaxAge": 31536000,
    "hstsIncludeSubDomains": false,
    "hardSessionExpirySeconds": null,
    "idleSessionExpirySeconds": 172800
  },
  "storage": {
    "masterKey": "pmk.STAail8VPUq2dgjKAVnAsw==",
    "masterKeyEnvironmentVariableName": null,
    "useEnvironmentForMasterKey": false,
    "flare": {
      "indexerPriority": 0.0,
      "queryParallelism": 4,
      "diskReaderLimit": 5
    }
  },
  "metastore": {
    "msSql": {
      "connectionString": null,
      "schema": null,
      "msiResource": null,
      "msiTenantId": null
    }
  },
  "firstRun": {
    "adminUsername": null,
    "adminPasswordHash": null,
    "requireAuthenticationForHttpIngestion": false
  },
  "services": {
    "servicesBaseUri": null
  }
}