Dropwizard Configuration Reference

Servers

Tweaking some of the options will require good understanding of how Jetty is working. See the Jetty architecture chapter for reference.

server:
  type: default
  maxThreads: 1024

All

Name	Default	Description
type	default	default simple
maxThreads	1024	The maximum number of threads the thread pool is allowed to grow. Jetty will throw java.lang.IllegalStateException: Insufficient threads: in case of too aggressive limit on the thread count.
minThreads	8	The minimum number of threads to keep alive in the thread pool. Note that each Jetty connector consumes threads from the pool. See HTTP connector how the thread counts are calculated.
maxQueuedRequests	1024	The maximum number of requests to queue before blocking the acceptors.
idleThreadTimeout	1 minute	The amount of time a worker thread can be idle before being stopped.
nofileSoftLimit	(none)	The number of open file descriptors before a soft error is issued. Requires Jetty’s libsetuid.so on java.library.path.
nofileHardLimit	(none)	The number of open file descriptors before a hard error is issued. Requires Jetty’s libsetuid.so on java.library.path.
gid	(none)	The group ID to switch to once the connectors have started. Requires Jetty’s libsetuid.so on java.library.path.
uid	(none)	The user ID to switch to once the connectors have started. Requires Jetty’s libsetuid.so on java.library.path.
user	(none)	The username to switch to once the connectors have started. Requires Jetty’s libsetuid.so on java.library.path.
group	(none)	The group to switch to once the connectors have started. Requires Jetty’s libsetuid.so on java.library.path.
umask	(none)	The umask to switch to once the connectors have started. Requires Jetty’s libsetuid.so on java.library.path.
startsAsRoot	(none)	Whether or not the Dropwizard application is started as a root user. Requires Jetty’s libsetuid.so on java.library.path.
shutdownGracePeriod	30 seconds	The maximum time to wait for Jetty, and all Managed instances, to cleanly shutdown before forcibly terminating them.
allowedMethods	GET, POST, PUT, DELETE, HEAD, OPTIONS, PATCH	The set of allowed HTTP methods. Others will be rejected with a 405 Method Not Allowed response.
rootPath	/*	The URL pattern relative to applicationContextPath from which the JAX-RS resources will be served.
registerDefaultExceptionMappers	true	Whether or not the default Jersey ExceptionMappers should be registered. Set this to false if you want to register your own.
enableThreadNameFilter	true	Whether or not to apply the ThreadNameFilter that adjusts thread names to include the request method and request URI.
dumpAfterStart	false	Whether or not to dump Jetty Diagnostics after start.
dumpBeforeStop	false	Whether or not to dump Jetty Diagnostics before stop.

GZip

server:
  gzip:
    bufferSize: 8KiB

Name	Default	Description
enabled	true	If true, all requests with gzip in the Accept-Encoding header will have their response entities compressed and requests with gzip in the Content-Encoding header will have their request entities decompressed.
minimumEntitySize	256 bytes	All response entities under this size are not compressed.
bufferSize	8KiB	The size of the buffer to use when compressing.
excludedUserAgentPatterns	[]	The set of user agent patterns to exclude from compression.
compressedMimeTypes	Jetty’s default	The list of mime types to compress. The default is all types apart the commonly known image, video, audio and compressed types.
includedMethods	Jetty’s default	The list of HTTP methods to compress. The default is to compress only GET responses.
deflateCompressionLevel	-1	The compression level used for deflation(compression).
gzipCompatibleInflation	true	This option is unused and deprecated as compressed requests without header info are unsupported
syncFlush	false	The flush mode. Set to true if the application wishes to stream (e.g. SSE) the data, but this may hurt compression performance (as all pending output is flushed).

Request Log

The new request log uses the logback-access library for processing request logs, which allow to use an extended set of logging patterns. See the logback-access-pattern docs for the reference.

server:
  requestLog:
    appenders:
      - type: console

Name	Default	Description
appenders	console appender	The set of AppenderFactory appenders to which requests will be logged. See logging for more info.

Classic Request Log

The classic request log uses the logback-classic library for processing request logs. It produces logs only in the standard NCSA common log format, but allows to use an extended set of appenders.

server:
  requestLog:
    type: classic
    timeZone: UTC
    appenders:
      - type: console

Name	Default	Description
timeZone	UTC	The time zone to which request timestamps will be converted.
appenders	console appender	The set of AppenderFactory appenders to which requests will be logged. See logging for more info.

Server Push

Server push technology allows a server to send additional resources to a client along with the requested resource. It works only for HTTP/2 connections.

server:
  serverPush:
    enabled: true
    associatePeriod: '4 seconds'
    maxAssociations: 16
    refererHosts: ['dropwizard.io', 'dropwizard.github.io']
    refererPorts: [8444, 8445]

Name	Default	Description
enabled	false	If true, the filter will organize resources as primary resources (those referenced by the Referer header) and secondary resources (those that have the Referer header). Secondary resources that have been requested within a time window from the request of the primary resource will be associated with it. The next time a client requests the primary resource, the server will send to the client the secondary resources along with the primary in a single response.
associatePeriod	4 seconds	The time window within which a request for a secondary resource will be associated to a primary resource.
maxAssociations	16	The maximum number of secondary resources that may be associated to a primary resource.
refererHosts	All hosts	The list of referrer hosts for which the server push technology is supported.
refererPorts	All ports	The list of referrer ports for which the server push technology is supported.

Simple

Extends the attributes that are available to all servers

server:
  type: simple
  applicationContextPath: /application
  adminContextPath: /admin
  connector:
    type: http
    port: 8080

Name	Default	Description
connector	http connector	HttpConnectorFactory HTTP connector listening on port 8080. The ConnectorFactory connector which will handle both application and admin requests. TODO link to connector below.
applicationContextPath	/application	The context path of the application servlets, including Jersey.
adminContextPath	/admin	The context path of the admin servlets, including metrics and tasks.

Default

Extends the attributes that are available to all servers

server:
  adminMinThreads: 1
  adminMaxThreads: 64
  adminContextPath: /
  applicationContextPath: /
  applicationConnectors:
    - type: http
      port: 8080
    - type: https
      port: 8443
      keyStorePath: example.keystore
      keyStorePassword: example
      validateCerts: false
  adminConnectors:
    - type: http
      port: 8081
    - type: https
      port: 8444
      keyStorePath: example.keystore
      keyStorePassword: example
      validateCerts: false

Name	Default	Description
applicationConnectors	An HTTP connector listening on port 8080.	A set of connectors which will handle application requests.
adminConnectors	An HTTP connector listening on port 8081.	An HTTP connector listening on port 8081. A set of connectors which will handle admin requests.
adminMinThreads	1	The minimum number of threads to use for admin requests.
adminMaxThreads	64	The maximum number of threads to use for admin requests.
adminContextPath	/	The context path of the admin servlets, including metrics and tasks.
applicationContextPath	/	The context path of the application servlets, including Jersey.

Connectors

HTTP

# Extending from the default server configuration
server:
  applicationConnectors:
    - type: http
      port: 8080
      bindHost: 127.0.0.1 # only bind to loopback
      inheritChannel: false
      headerCacheSize: 512 bytes
      outputBufferSize: 32KiB
      maxRequestHeaderSize: 8KiB
      maxResponseHeaderSize: 8KiB
      inputBufferSize: 8KiB
      idleTimeout: 30 seconds
      minBufferPoolSize: 64 bytes
      bufferPoolIncrement: 1KiB
      maxBufferPoolSize: 64KiB
      minRequestDataPerSecond: '0 bytes'
      minResponseDataPerSecond: '0 bytes'
      acceptorThreads: 1
      selectorThreads: 2
      acceptQueueSize: 1024
      reuseAddress: true
      useServerHeader: false
      useDateHeader: true
      useForwardedHeaders: false
      useProxyProtocol: false
      httpCompliance: RFC7230

Name	Default	Description
port	8080	The TCP/IP port on which to listen for incoming connections.
bindHost	(none)	The hostname to bind to.
inheritChannel	false	Whether this connector uses a channel inherited from the JVM. Use it with Server::Starter, to launch an instance of Jetty on demand.
headerCacheSize	512 bytes	The size of the header field cache.
outputBufferSize	32KiB	The size of the buffer into which response content is aggregated before being sent to the client. A larger buffer can improve performance by allowing a content producer to run without blocking, however larger buffers consume more memory and may induce some latency before a client starts processing the content.
maxRequestHeaderSize	8KiB	The maximum size of a request header. Larger headers will allow for more and/or larger cookies plus larger form content encoded in a URL. However, larger headers consume more memory and can make a server more vulnerable to denial of service attacks.
maxResponseHeaderSize	8KiB	The maximum size of a response header. Larger headers will allow for more and/or larger cookies and longer HTTP headers (eg for redirection). However, larger headers will also consume more memory.
inputBufferSize	8KiB	The size of the per-connection input buffer.
idleTimeout	30 seconds	The maximum idle time for a connection, which roughly translates to the java.net.Socket#setSoTimeout(int) call, although with NIO implementations other mechanisms may be used to implement the timeout. The max idle time is applied when waiting for a new message to be received on a connection or when waiting for a new message to be sent on a connection. This value is interpreted as the maximum time between some progress being made on the connection. So if a single byte is read or written, then the timeout is reset.
minBufferPoolSize	64 bytes	The minimum size of the buffer pool.
bufferPoolIncrement	1KiB	The increment by which the buffer pool should be increased.
maxBufferPoolSize	64KiB	The maximum size of the buffer pool.
minRequestDataPerSecond	0	The minimum request data rate in bytes per second; or <= 0 for no limit.
minResponseDataPerSecond	0	The minimum response data rate in bytes per second; or <= 0 for no limit.
acceptorThreads	(Jetty’s default)	The number of worker threads dedicated to accepting connections. By default is max(1, min(4, #CPUs/8)).
selectorThreads	(Jetty’s default)	The number of worker threads dedicated to sending and receiving data. By default is max(1, min(4, #CPUs/2)).
acceptQueueSize	(OS default)	The size of the TCP/IP accept queue for the listening socket.
reuseAddress	true	Whether or not SO_REUSEADDR is enabled on the listening socket.
useServerHeader	false	Whether or not to add the Server header to each response.
useDateHeader	true	Whether or not to add the Date header to each response.
useForwardedHeaders	false	Whether or not to look at X-Forwarded-* headers added by proxies. See ForwardedRequestCustomizer for details.
useProxyProtocol	false	Whether or not to accept PROXY protocol requests from a reverse proxy such as HAProxy. ProxyConnectionFactory supports version 1 and 2 of the PROXY protocol.
httpCompliance	RFC7230	This sets the http compliance level used by Jetty when parsing http, this can be useful when using a non-RFC7230 compliant front end, such as nginx, which can produce multi-line headers when forwarding client certificates using proxy_set_header X-SSL-CERT $ssl_client_cert; Possible values are set forth in the org.eclipse.jetty.http.HttpCompliance enum: RFC7230: Disallow header folding. RFC2616: Allow header folding.
requestCookieCompliance	RFC6265	This sets the cookie compliance level used by Jetty when parsing request Cookie headers, this can be useful when needing to support Version=1 cookies defined in RFC2109 (and continued in RFC2965) which allows for special/reserved characters (control, separator, et al) to be enclosed within double quotes when used in a cookie value; Possible values are set forth in the org.eclipse.jetty.http.CookieCompliance enum: RFC6265: Special characters in cookie values must be encoded. RFC2965: Allows for special characters enclosed within double quotes.
responseCookieCompliance	RFC6265	This sets the cookie compliance level used by Jetty when generating response Set-Cookie headers, this can be useful when needing to support Version=1 cookies defined in RFC2109 (and continued in RFC2965) which allows for special/reserved characters (control, separator, et al) to be enclosed within double quotes when used in a cookie value; Possible values are set forth in the org.eclipse.jetty.http.CookieCompliance enum: RFC6265: Special characters in cookie values must be encoded. RFC2965: Allows for special characters enclosed within double quotes.

HTTPS

Extends the attributes that are available to the HTTP connector

# Extending from the default server configuration
server:
  applicationConnectors:
    - type: https
      port: 8443
      ....
      keyStorePath: /path/to/file
      keyStorePassword: changeit
      keyStoreType: JKS
      keyStoreProvider:
      trustStorePath: /path/to/file
      trustStorePassword: changeit
      trustStoreType: JKS
      trustStoreProvider:
      keyManagerPassword: changeit
      needClientAuth: false
      wantClientAuth:
      certAlias: <alias>
      crlPath: /path/to/file
      enableCRLDP: false
      enableOCSP: false
      maxCertPathLength: (unlimited)
      ocspResponderUrl: (none)
      jceProvider: (none)
      validateCerts: false
      validatePeers: false
      supportedProtocols: (JVM default)
      excludedProtocols: [SSL, SSLv2, SSLv2Hello, SSLv3] # (Jetty's default)
      supportedCipherSuites: (JVM default)
      excludedCipherSuites: [.*_(MD5|SHA|SHA1)$] # (Jetty's default)
      allowRenegotiation: true
      endpointIdentificationAlgorithm: (none)

Name	Default	Description
keyStorePath	REQUIRED	The path to the Java key store which contains the host certificate and private key.
keyStorePassword	REQUIRED	The password used to access the key store.
keyStoreType	JKS	The type of key store (usually JKS, PKCS12, JCEKS, Windows-MY}, or Windows-ROOT).
keyStoreProvider	(none)	The JCE provider to use to access the key store.
trustStorePath	(none)	The path to the Java key store which contains the CA certificates used to establish trust.
trustStorePassword	(none)	The password used to access the trust store.
trustStoreType	JKS	The type of trust store (usually JKS, PKCS12, JCEKS, Windows-MY, or Windows-ROOT).
trustStoreProvider	(none)	The JCE provider to use to access the trust store.
keyManagerPassword	(none)	The password, if any, for the key manager.
needClientAuth	(none)	Whether or not client authentication is required.
wantClientAuth	(none)	Whether or not client authentication is requested.
certAlias	(none)	The alias of the certificate to use.
crlPath	(none)	The path to the file which contains the Certificate Revocation List.
enableCRLDP	false	Whether or not CRL Distribution Points (CRLDP) support is enabled.
enableOCSP	false	Whether or not On-Line Certificate Status Protocol (OCSP) support is enabled.
maxCertPathLength	(unlimited)	The maximum certification path length.
ocspResponderUrl	(none)	The location of the OCSP responder.
jceProvider	(none)	The name of the JCE provider to use for cryptographic support. See Oracle documentation for more information.
validateCerts	false	Whether or not to validate TLS certificates before starting. If enabled, Dropwizard will refuse to start with expired or otherwise invalid certificates. This option will cause unconditional failure in Dropwizard 1.x until a new validation mechanism can be implemented.
validatePeers	false	Whether or not to validate TLS peer certificates. This option will cause unconditional failure in Dropwizard 1.x until a new validation mechanism can be implemented.
supportedProtocols	(none)	A list of protocols (e.g., SSLv3, TLSv1) which are supported. All other protocols will be refused.
excludedProtocols	[“SSL.*”, “TLSv1”, “TLSv1\.1”]	A list of protocols (e.g., SSLv3, TLSv1) which are excluded. These protocols will be refused.
supportedCipherSuites	(none)	A list of cipher suites (e.g., TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256) which are supported. All other cipher suites will be refused.
excludedCipherSuites	(none)	A list of cipher suites (e.g., TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256) which are excluded. These cipher suites will be refused and exclusion takes higher precedence than inclusion, such that if a cipher suite is listed in supportedCipherSuites and excludedCipherSuites, the cipher suite will be excluded. To verify that the proper cipher suites are being whitelisted and blacklisted, it is recommended to use the tool sslyze.
allowRenegotiation	true	Whether or not TLS renegotiation is allowed.
endpointIdentificationAlgorithm	(none)	Which endpoint identification algorithm, if any, to use during the TLS handshake.

HTTP/2 over TLS

HTTP/2 is a new protocol, intended as a successor of HTTP/1.1. It adds several important features like binary structure, stream multiplexing over a single connection, header compression, and server push. At the same time it remains semantically compatible with HTTP/1.1, which should make the upgrade process more seamless. Checkout HTTP/2 FAQ for the further information.

For an encrypted connection HTTP/2 uses ALPN protocol. It’s a TLS extension, that allows a client to negotiate a protocol to use after the handshake is complete. If either side does not support ALPN, then the protocol will be ignored, and an HTTP/1.1 connection over TLS will be used instead.

For this connector to work with ALPN protocol you need to either:

• Enable native SSL support via Google’s Conscrypt as described in the SSL section of the Core manual; or

• Provide alpn-boot library to JVM’s bootpath. The correct library version depends on the JVM version. Consult Jetty ALPN guide for the reference.

Note that your JVM also must provide TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 cipher. The specification states that HTTP/2 deployments must support it to avoid handshake failures. It’s the single supported cipher in HTTP/2 connector by default. In case you want to support more strong ciphers, you should specify them in the supportedCipherSuites parameter along with TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256.

This connector extends the attributes that are available to the HTTPS connector

server:
  applicationConnectors:
    - type: h2
      port: 8445
      maxConcurrentStreams: 1024
      initialStreamRecvWindow: 65535
      keyStorePath: /path/to/file # required
      keyStorePassword: changeit
      trustStorePath: /path/to/file # required
      trustStorePassword: changeit
      supportedCipherSuites: # optional
        - TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
        - TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256

Name	Default	Description
maxConcurrentStreams	1024	The maximum number of concurrently open streams allowed on a single HTTP/2 connection. Larger values increase parallelism, but cost a memory commitment.
initialStreamRecvWindow	65535	The initial flow control window size for a new stream. Larger values may allow greater throughput, but also risk head of line blocking if TCP/IP flow control is triggered.

HTTP/2 Plain Text

HTTP/2 promotes using encryption, but doesn’t require it. However, most browsers stated that they will not support HTTP/2 without encryption. Currently no browser supports HTTP/2 unencrypted.

The connector should only be used in closed secured networks or during development. It expects from clients an HTTP/1.1 OPTIONS request with Upgrade : h2c header to indicate a wish to upgrade to HTTP/2, or a request with the HTTP/2 connection preface. If the client doesn’t support HTTP/2, a plain HTTP/1.1 connections will be used instead.

This connector extends the attributes that are available to the HTTP connector

server:
  applicationConnectors:
    - type: h2c
      port: 8446
      maxConcurrentStreams: 1024
      initialStreamRecvWindow: 65535

Name	Default	Description
maxConcurrentStreams	1024	The maximum number of concurrently open streams allowed on a single HTTP/2 connection. Larger values increase parallelism, but cost a memory commitment.
initialStreamRecvWindow	65535	The initial flow control window size for a new stream. Larger values may allow greater throughput, but also risk head of line blocking if TCP/IP flow control is triggered.

Tasks

admin:
  tasks:
    printStackTraceOnError: true

Name	Default	Description
printStackTraceOnError	false	Print the full stack trace when the execution of a task failed.

Health checks

admin:
  healthChecks:
    minThreads: 1
    maxThreads: 4
    workQueueSize: 1

Name		Default Description
minThreads	1	The minimum number of threads for executing health checks.
maxThreads	4	The maximum number of threads for executing health checks.
workQueueSize	1	The length of the work queue for health check executions.

Logging

logging:
  level: INFO
  loggers:
    "io.dropwizard": INFO
    "org.hibernate.SQL":
      level: DEBUG
      additive: false
      appenders:
        - type: file
          currentLogFilename: /var/log/myapplication-sql.log
          archivedLogFilenamePattern: /var/log/myapplication-sql-%d.log.gz
          archivedFileCount: 5
  appenders:
    - type: console

Name	Default	Description
level	Level.INFO	Logback logging level.
additive	true	Logback additive setting.
loggers	(none)	Individual logger configuration (both forms are acceptable).
appenders	(none)	One of console, file or syslog.

Console

logging:
  level: INFO
  appenders:
    - type: console
      threshold: ALL
      queueSize: 512
      discardingThreshold: 0
      timeZone: UTC
      target: stdout
      logFormat: "%-5p [%d{ISO8601,UTC}] %c: %m%n%rEx"
      filterFactories:
        - type: URI

Name	Default	Description
type	REQUIRED	The appender type. Must be console.
threshold	ALL	The lowest level of events to print to the console.
queueSize	256	The maximum capacity of the blocking queue.
discardingThreshold	-1	When the blocking queue has only the capacity mentioned in discardingThreshold remaining, it will drop events of level TRACE, DEBUG and INFO, keeping only events of level WARN and ERROR. If no discarding threshold is specified (-1), then a default of queueSize / 5 (logback’s default ratio) is used. To keep all events, set discardingThreshold to 0.
timeZone	UTC	The time zone to which event timestamps will be converted. To use the system/default time zone, set it to system.
target	stdout	The name of the standard stream to which events will be written. Can be stdout or stderr.
logFormat	%-5p [%d{ISO8601,UTC}] %c: %m%n%rEx	The Logback pattern with which events will be formatted. See the Logback documentation for details. The default log pattern is `%h %l %u [%t{dd/MMM/yyyy:HH:mm:ss Z,UTC}] "%r" %s %b "%i{Referer}" "%i{User-Agent}" %D`. Use the placeholder %dwTimeZone to include the value of timeZone in the pattern.
filterFactories	(none)	The list of filters to apply to the appender, in order, after the threshold.
neverBlock	false	Prevent the wrapping asynchronous appender from blocking when its underlying queue is full. Set to true to disable blocking.

File

logging:
  level: INFO
  appenders:
    - type: file
      currentLogFilename: /var/log/myapplication.log
      threshold: ALL
      queueSize: 512
      discardingThreshold: 0
      archive: true
      archivedLogFilenamePattern: /var/log/myapplication-%d.log
      archivedFileCount: 5
      timeZone: UTC
      logFormat: "%-5p [%d{ISO8601,UTC}] %c: %m%n%rEx"
      bufferSize: 8KiB
      immediateFlush: true
      filterFactories:
        - type: URI

Name	Default	Description
type	REQUIRED	The appender type. Must be file.
currentLogFilename	REQUIRED	The filename where current events are logged.
threshold	ALL	The lowest level of events to write to the file.
queueSize	256	The maximum capacity of the blocking queue.
discardingThreshold	-1	When the blocking queue has only the capacity mentioned in discardingThreshold remaining, it will drop events of level TRACE, DEBUG and INFO, keeping only events of level WARN and ERROR. If no discarding threshold is specified (-1), then a default of queueSize / 5 (logback’s default ratio) is used. To keep all events, set discardingThreshold to 0.
archive	true	Whether or not to archive old events in separate files.
archivedLogFilenamePattern	(none)	Required if archive is true. The filename pattern for archived files. If maxFileSize is specified, rollover is size-based, and the pattern must contain %i for an integer index of the archived file. Otherwise rollover is date-based, and the pattern must contain %d, which is replaced with the date in yyyy-MM-dd form. If the pattern ends with .gz or .zip, files will be compressed as they are archived.
archivedFileCount	5	The number of archived files to keep. Must be greater than or equal to 0. Zero is a special value signifying to keep infinite logs (use with caution)
maxFileSize	(unlimited)	The maximum size of the currently active file before a rollover is triggered. The value can be expressed in bytes, kibibytes, kilobytes, mebibytes, megabytes, gibibytes, gigabytes, tebibytes, terabytes, pebibytes, and petabytes by appending B, KiB, KB, MiB, MB, GiB, GB, TiB, TB, PiB, or PB to the numeric value. Examples include 5KiB, 100MiB, 1GiB, 1TB. Sizes can also be spelled out, such as 5 kibibytes, 100 mebibytes, 1 gibibyte, 1 terabyte.
totalSizeCap	(unlimited)	Controls the total size of all files. Oldest archives are deleted asynchronously when the total size cap is exceeded.
timeZone	UTC	The time zone to which event timestamps will be converted.
logFormat	%-5p [%d{ISO8601,UTC}] %c: %m%n%rEx	The Logback pattern with which events will be formatted. See the Logback documentation for details. The default log pattern is `%h %l %u [%t{dd/MMM/yyyy:HH:mm:ss Z,UTC}] "%r" %s %b "%i{Referer}" "%i{User-Agent}" %D`. Use the placeholder %dwTimeZone to include the value of timeZone in the pattern.
filterFactories	(none)	The list of filters to apply to the appender, in order, after the threshold.
neverBlock	false	Prevent the wrapping asynchronous appender from blocking when its underlying queue is full. Set to true to disable blocking.
bufferSize	8KiB	The buffer size of the underlying FileAppender (setting added in logback 1.1.10). Increasing this from the default of 8KiB to 256KiB is reported to significantly reduce thread contention.
immediateFlush	true	If set to true, log events will be immediately flushed to disk. Immediate flushing is safer, but it degrades logging throughput.

Syslog

logging:
  level: INFO
  appenders:
    - type: syslog
      host: localhost
      port: 514
      facility: local0
      threshold: ALL
      stackTracePrefix: \t
      logFormat: "%-5p [%d{ISO8601,UTC}] %c: %m%n%rEx"
      filterFactories:
        - type: URI

Name	Default	Description
host	localhost	The hostname of the syslog server.
port	514	The port on which the syslog server is listening.
facility	local0	The syslog facility to use. Can be either auth, authpriv, daemon, cron, ftp, lpr, kern, mail, news, syslog, user, uucp, local0, local1, local2, local3, local4, local5, local6, or local7.
threshold	ALL	The lowest level of events to write to the file.
logFormat	%-5p [%d{ISO8601,UTC}] %c: %m%n%rEx	The Logback pattern with which events will be formatted. See the Logback documentation for details. The default log pattern is `%h %l %u [%t{dd/MMM/yyyy:HH:mm:ss Z,UTC}] "%r" %s %b "%i{Referer}" "%i{User-Agent}" %D`.
stackTracePrefix	t	The prefix to use when writing stack trace lines (these are sent to the syslog server separately from the main message)
filterFactories	(none)	The list of filters to apply to the appender, in order, after the threshold.
neverBlock	false	Prevent the wrapping asynchronous appender from blocking when its underlying queue is full. Set to true to disable blocking.
includeStackTrace	true	Set to false to disable sending stack traces to the syslog service.

TCP

logging:
  level: INFO
  appenders:
    - type: tcp
      host: localhost
      port: 4560
      connectionTimeout: 500ms
      immediateFlush: true
      sendBufferSize: 8KiB

Name	Default	Description
host	localhost	The hostname of the TCP server.
port	4560	The port on which the TCP server is listening.
connectionTimeout	500ms	The timeout to connect to the TCP server.
immediateFlush	true	If set to true, log events will be immediately send to the server Immediate flushing is safer, but it degrades logging throughput.
sendBufferSize	8KiB	The buffer size of the underlying SocketAppender. Takes into effect if immediateFlush is disabled.

UDP

logging:
  level: INFO
  appenders:
    - type: udp
      host: localhost
      port: 514

Name	Default	Description
host	localhost	The hostname of the UDP server.
port	514	The port on which the UDP server is listening.

FilterFactories

A factory used for request logging appenders should implement io.dropwizard.logging.filter.FilterFactory<IAccessEvent> while one used for regular logging should implement io.dropwizard.logging.filter.FilterFactory<ILoggingEvent>. To register a factory, its fully qualified classname must be listed in META-INF/services/io.dropwizard.logging.filter.FilterFactory. The factory then can be referenced in the configuration either via its simple classname or via type name, if factory class annotated with @JsonTypeName.

logging:
  level: INFO
  appenders:
    - type: console
      filterFactories:
        - type: URI

Name	Default	Description
type	REQUIRED	The filter type name.

JSON layout

layout:
  type: json
  timestampFormat: "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
  prettyPrint: false
  appendLineSeparator: true
  includes: [timestamp, threadName, level, loggerName, message, mdc, exception]
  customFieldNames:
    timestamp: "@timestamp"
  additionalFields:
    service-name: "user-service"
  includesMdcKeys: [userId]
  flattenMdc: true
  exception:
    rootFirst: true
    depth: full
    evaluators: [org.apache]

Name	Default	Description
timestampFormat	(none)	By default, the timestamp is not formatted. To customize how timestamps are formatted, set the property to the corresponding DateTimeFormatter string or one of the predefined formats (e.g. ISO_LOCAL_TIME, ISO_ZONED_DATE_TIME, RFC_1123_DATE_TIME).
prettyPrint	false	Whether the JSON output should be formatted for human readability.
appendLineSeparator	true	Whether to append a line separator at the end of the message formatted as JSON.
includes	(timestamp, level, threadName, mdc, loggerName, message, exception)	Set of logging event attributes to include in the JSON map: timestamp true Whether to include the timestamp as the timestamp field. level true Whether to include the logging level as the level field. threadName true Whether to include the thread name as the thread field. mdc true Whether to include the MDC properties as the mdc field. loggerName true Whether to include the logger name as the logger field. message true Whether to include the formatted message as the message field. exception true Whether to log exceptions. If the property enabled and there is an exception, it will be formatted to a string as the exception field. contextName false Whether to include the logging context name as the context field .
customFieldNames	(empty)	Map of field name replacements . For example (requestTime:request_time, userAgent:user_agent).
additionalFields	(empty)	Map of fields to add in the JSON map.
includesMdcKeys	(empty)	Set of MDC keys which should be included in the JSON map. By default includes everything.
flattenMdc	false	Flatten the MDC to the root of the JSON object instead of nested in the mdc field.
exception	(empty)	The exception configuration for the exception field.

Exception

layout:
  type: json
  exception:
    rootFirst: false
    depth: 25
    evaluators: [org.apache]

Name	Default	Description
rootFirst	true	Whether the root cause should be displayed first.
depth	full	The stack trace depth.
evaluators	(empty)	The packages to filter from the stacktrace.

JSON access log layout

layout:
  type: access-json
  timestampFormat: "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
  prettyPrint: false
  appendLineSeparator: true
  includes: [timestamp, remoteAddress, remoteUser, protocol, method, requestUri, statusCode, requestTime, contentLength, userAgent]
  requestHeaders:
    - X-Request-Id
  responseHeaders:
    - X-Request-Id
  requestAttributes:
    - SomeAttributeName
  customFieldNames:
    timestamp: "@timestamp"
  additionalFields:
    service-name: "user-service"

Name	Default	Description
timestampFormat	(none)	By default, the timestamp is not formatted. To customize how timestamps are formatted, set the property to the corresponding DateTimeFormatter string or one of the predefined formats (e.g. ISO_LOCAL_TIME, ISO_ZONED_DATE_TIME,``RFC_1123_DATE_TIME``).
prettyPrint	false	Whether the JSON output should be formatted for human readability.
appendLineSeparator	true	Whether to append a line separator at the end of the message formatted as JSON.
includes	(timestamp, remoteAddress, protocol, method, requestUri, statusCode, requestTime, contentLength, userAgent)	Set of logging event attributes to include in the JSON map: contentLength true Whether to include the response content length, if it’s known as the contentLength field. method true Whether to include the request HTTP method as the method field. remoteAddress true Whether to include the IP address of the client or last proxy that sent the request as the remoteAddress field. remoteUser true Whether to include information about the remote user as the remoteUser field. requestTime true Whether to include the time elapsed between receiving the request and logging it as the requestTime field. Time is in ms. requestUri true Whether to include the URI of the request as the uri field. statusCode true Whether to include the status code of the response as the status field. protocol true Whether to include the request HTTP protocol as the protocol field. timestamp true Whether to include the timestamp of the event the timestamp field. userAgent true Whether to include the user agent of the request as the userAgent field. requestParameters false Whether to include the request parameters as the params field. requestContent false Whether to include the body of the request as the requestContent field. Must register the TeeFilter to be effective. requestUrl false Whether to include the request URL (method, URI, query parameters, protocol) as the url field. pathQuery false Whether to include the URI and query parameters of the request as the pathQuery field. remoteHost false Whether to include the fully qualified name of the client or the last proxy that sent the request as the remoteHost field. responseContent false Whether to include the response body as the responseContent field. Must register the TeeFilter to be effective. serverName false Whether to include the name of the server to which the request was sent as the serverName field.
requestHeaders	(empty)	Set of request headers included in the JSON map as the headers field.
responseHeaders	(empty)	Set of response headers included in the JSON map as the responseHeaders field.
requestAttributes	(empty)	Set of ServletRequest attributes included in the JSON map as the requestAttributes field.
customFieldNames	(empty)	Map of field name replacements in the JSON map. For example requestTime:request_time, userAgent:user_agent).
additionalFields	(empty)	Map of fields to add in the JSON map.

Metrics

The metrics configuration has three fields; frequency, reporters and reportOnStop.

metrics:
  frequency: 1 minute
  reporters:
    - type: <type>
  reportOnStop: false

Name	Default	Description
frequency	1 minute	The frequency to report metrics. Overridable per-reporter.
reporters	(none)	A list of reporters to report metrics.
reportOnStop	false	To report metrics one last time when stopping Dropwizard.

All Reporters

The following options are available for all metrics reporters.

metrics:
  reporters:
    - type: <type>
      durationUnit: milliseconds
      rateUnit: seconds
      excludes: (none)
      includes: (all)
      excludesAttributes: (none)
      includesAttributes: (all)
      useRegexFilters: false
      frequency: 1 minute

Name	Default	Description
durationUnit	milliseconds	The unit to report durations as. Overrides per-metric duration units.
rateUnit	seconds	The unit to report rates as. Overrides per-metric rate units.
excludes	(none)	Metrics to exclude from reports, by name. When defined, matching metrics will not be reported.
includes	(all)	Metrics to include in reports, by name. When defined, only these metrics will be reported.
excludesAttributes	(none)	Metric attributes to exclude from reports, by name (e.g. p98, m15_rate, stddev). When defined, matching metrics attributes will not be reported.
includesAttributes	(all)	Metrics attributes to include in reports, by name (e.g. p98, m15_rate, stddev). When defined, only these attributes will be reported.
useRegexFilters	false	Indicates whether the values of the ‘includes’ and ‘excludes’ fields should be treated as regular expressions or not.
useSubstringMatching	false	Uses a substring matching strategy to determine whether a metric should be processed.
frequency	(none)	The frequency to report metrics. Overrides the default.

The inclusion and exclusion rules are defined as:

• If includes is empty, then all metrics are included;

• If includes is not empty, only metrics from this list are included;

• If excludes is empty, no metrics are excluded;

• If excludes is not empty, then exclusion rules take precedence over inclusion rules. Thus if a name matches the exclusion rules it will not be included in reports even if it also matches the inclusion rules.

When neither useRegexFilters nor useSubstringMatching are enabled, a default exact matching strategy will be used to determine whether a metric should be processed. In case both useRegexFilters and useSubstringMatching are set, useRegexFilters takes precedence over useSubstringMatching.

Formatted Reporters

These options are available only to “formatted” reporters and extend the options available to all reporters

metrics:
  reporters:
    - type: <type>
      locale: <system default>

Name	Default	Description
locale	System default	The Locale for formatting numbers, dates and times.

Console Reporter

Reports metrics periodically to the console.

Extends the attributes that are available to formatted reporters

metrics:
  reporters:
    - type: console
      timeZone: UTC
      output: stdout

Name	Default	Description
timeZone	UTC	The timezone to display dates/times for.
output	stdout	The stream to write to. One of stdout or stderr.

CSV Reporter

Reports metrics periodically to a CSV file.

Extends the attributes that are available to formatted reporters

metrics:
  reporters:
    - type: csv
      file: /path/to/file

Name	Default	Description
file	No default	The CSV file to write metrics to.

Graphite Reporter

Reports metrics periodically to Graphite.

Extends the attributes that are available to all reporters

Note

You will need to add dropwizard-metrics-graphite to your POM.

metrics:
  reporters:
    - type: graphite
      host: localhost
      port: 2003
      prefix: <prefix>
      transport: tcp

Name	Default	Description
host	localhost	The hostname of the Graphite server to report to.
port	2003	The port of the Graphite server to report to.
prefix	(none)	The prefix for Metric key names to report to Graphite.
transport	tcp	The type of transport to report to Graphite with (“tcp” or “udp”).

SLF4J

Reports metrics periodically by logging via SLF4J.

Extends the attributes that are available to all reporters

See BaseReporterFactory and BaseFormattedReporterFactory for more options.

metrics:
  reporters:
    - type: log
      logger: metrics
      markerName: <marker name>

Name	Default	Description
logger	metrics	The name of the logger to write metrics to.
markerName	(none)	The name of the marker to mark logged metrics with.

Clients

HttpClient

See HttpClientConfiguration for more options.

httpClient:
  timeout: 500ms
  connectionTimeout: 500ms
  timeToLive: 1h
  cookiesEnabled: false
  maxConnections: 1024
  maxConnectionsPerRoute: 1024
  keepAlive: 0ms
  retries: 0
  userAgent: <application name> (<client name>)

Name	Default	Description
timeout	500 milliseconds	The maximum idle time for a connection, once established.
connectionTimeout	500 milliseconds	The maximum time to wait for a connection to open.
connectionRequestTimeout	500 milliseconds	The maximum time to wait for a connection to be returned from the connection pool.
timeToLive	1 hour	The maximum time a pooled connection can stay idle (not leased to any thread) before it is shut down.
cookiesEnabled	false	Whether or not to enable cookies.
maxConnections	1024	The maximum number of concurrent open connections.
maxConnectionsPerRoute	1024	The maximum number of concurrent open connections per route.
keepAlive	0 milliseconds	The maximum time a connection will be kept alive before it is reconnected. If set to 0, connections will be immediately closed after every request/response.
retries	0	The number of times to retry failed requests. Requests are only retried if they throw an exception other than InterruptedIOException, UnknownHostException, ConnectException, or SSLException.
userAgent	applicationName (clientName)	The User-Agent to send with requests.
validateAfterInactivityPeriod	0 milliseconds	The maximum time before a persistent connection is checked to remain active. If set to 0, no inactivity check will be performed.

Proxy

httpClient:
  proxy:
    host: 192.168.52.11
    port: 8080
    scheme : http
    auth:
      username: secret
      password: stuff
      authScheme: NTLM
      realm: realm
      hostname: host
      domain: WINDOWSDOMAIN
      credentialType: NT
    nonProxyHosts:
      - localhost
      - '192.168.52.*'
      - '*.example.com'

Name	Default	Description
host	REQUIRED	The proxy server host name or ip address.
port	(scheme default)	The proxy server port. If the port is not set then the scheme default port is used.
scheme	http	The proxy server URI scheme. HTTP and HTTPS schemas are permitted. By default HTTP scheme is used.
auth	(none)	The proxy server Basic or NTLM authentication schemes. If they are not set then no credentials will be passed to the server.
username	REQUIRED	The username used to connect to the server.
password	REQUIRED	The password used to connect to the server.
authScheme	Basic	The authentication scheme used by the. Allowed options are: Basic, NTLM
realm	(none)	The realm, used for NTLM authentication.
hostname	(none)	The hostname of the windows workstation, used for NTLM authentication.
domain	(none)	The Windows Domain, used for NTLM authentication.
credentialType	(none)	The Apache HTTP Client Credentials implementation used for proxy authentication. Allowed options are: UsernamePassword or NT
nonProxyHosts	(none)	List of patterns of hosts that should be reached without proxy. The patterns may contain symbol ‘*’ as a wildcard. If a host matches one of the patterns it will be reached through a direct connection.

TLS

httpClient:
  tls:
    protocol: TLSv1.2
    provider: SunJSSE
    verifyHostname: true
    keyStorePath: /path/to/file
    keyStorePassword: changeit
    keyStoreType: JKS
    trustStorePath: /path/to/file
    trustStorePassword: changeit
    trustStoreType: JKS
    trustSelfSignedCertificates: false
    supportedProtocols: TLSv1.1,TLSv1.2
    supportedCipherSuites: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
    certAlias: alias-of-specific-cert

Name	Default	Description
protocol	TLSv1.2	The default protocol the client will attempt to use during the SSL Handshake. See here for more information.
provider	(none)	The name of the JCE provider to use on client side for cryptographic support (for example, SunJCE, Conscrypt, BC, etc). See Oracle documentation for more information.
verifyHostname	true	Whether to verify the hostname of the server against the hostname presented in the server certificate.
keyStorePath	(none)	The path to the Java key store which contains the client certificate and private key.
keyStorePassword	(none)	The password used to access the key store.
keyStoreType	JKS	The type of key store (usually JKS, PKCS12, JCEKS, Windows-MY, or Windows-ROOT).
trustStorePath	(none)	The path to the Java key store which contains the CA certificates used to establish trust.
trustStorePassword	(none)	The password used to access the trust store.
trustStoreType	JKS	The type of trust store (usually JKS, PKCS12, JCEKS, Windows-MY, or Windows-ROOT).
trustSelfSignedCertificates	false	If true, will trust all self-signed certificates regardless of trustStore settings. If false, trust decisions will be handled by the supplied trustStore.
supportedProtocols	(none)	A list of protocols (e.g., SSLv3, TLSv1) which are supported. All other protocols will be refused.
supportedCipherSuites	(none)	A list of cipher suites (e.g., TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256) which are supported. All other cipher suites will be refused.
certAlias	(none)	The alias of a specific client certificate to present when authenticating. Use this when the specified keystore has multiple certificates to force use of a non-default certificate.

JerseyClient

Extends the attributes that are available to http clients

See JerseyClientConfiguration and HttpClientConfiguration for more options.

jerseyClient:
  minThreads: 1
  maxThreads: 128
  workQueueSize: 8
  gzipEnabled: true
  gzipEnabledForRequests: true
  chunkedEncodingEnabled: true

Name	Default	Description
minThreads	1	The minimum number of threads in the pool used for asynchronous requests.
maxThreads	128	The maximum number of threads in the pool used for asynchronous requests. If asynchronous requests made by jersey client while serving requests, the number must be set according to the maxThread setting of the server. Otherwise some requests made to dropwizard on heavy load may fail due to congestion on the jersey client’s thread pool.
workQueueSize	8	The size of the work queue of the pool used for asynchronous requests. Additional threads will be spawn only if the queue is reached its maximum size.
gzipEnabled	true	Adds an Accept-Encoding: gzip header to all requests, and enables automatic gzip decoding of responses.
gzipEnabledForRequests	true	Adds a Content-Encoding: gzip header to all requests, and enables automatic gzip encoding of requests.
chunkedEncodingEnabled	true	Enables the use of chunked encoding for requests.

Database

database:
  driverClass : org.postgresql.Driver
  url: 'jdbc:postgresql://db.example.com/db-prod'
  user: pg-user
  password: iAMs00perSecrEET

Name	Default	Description
driverClass	REQUIRED	The full name of the JDBC driver class.
url	REQUIRED	The URL of the server.
user	none	The username used to connect to the server.
password	none	The password used to connect to the server.
removeAbandoned	false	Remove abandoned connections if they exceed removeAbandonedTimeout. If set to true a connection is considered abandoned and eligible for removal if it has been in use longer than the removeAbandonedTimeout and the condition for abandonWhenPercentageFull is met.
removeAbandonedTimeout	60 seconds	The time before a database connection can be considered abandoned.
abandonWhenPercentageFull	0	Connections that have been abandoned (timed out) won’t get closed and reported up unless the number of connections in use are above the percentage defined by abandonWhenPercentageFull. The value should be between 0-100.
alternateUsernamesAllowed	false	Set to true if the call getConnection(username,password) is allowed. This is used for when the pool is used by an application accessing multiple schemas. There is a performance impact turning this option on, even when not used.
commitOnReturn	false	Set to true if you want the connection pool to commit any pending transaction when a connection is returned.
rollbackOnReturn	false	Set to true if you want the connection pool to rollback any pending transaction when a connection is returned.
autoCommitByDefault	JDBC driver’s default	The default auto-commit state of the connections.
readOnlyByDefault	JDBC driver’s default	The default read-only state of the connections.
properties	none	Any additional JDBC driver parameters.
defaultCatalog	none	The default catalog to use for the connections.
defaultTransactionIsolation	JDBC driver’s default	The default transaction isolation to use for the connections. Can be one of none, default, read-uncommitted, read-committed, repeatable-read, or serializable.
useFairQueue	true	If true, calls to getConnection are handled in a FIFO manner.
initialSize	10	The initial size of the connection pool.
minSize	10	The minimum size of the connection pool.
maxSize	100	The maximum size of the connection pool.
initializationQuery	none	A custom query to be run when a connection is first created.
logAbandonedConnections	false	If true, logs stack traces of abandoned connections.
logValidationErrors	false	If true, logs errors when connections fail validation.
maxConnectionAge	none	If set, connections which have been open for longer than maxConnectionAge are closed when returned.
maxWaitForConnection	30 seconds	If a request for a connection is blocked for longer than this period, an exception will be thrown.
minIdleTime	1 minute	The minimum amount of time an connection must sit idle in the pool before it is eligible for eviction.
validationQuery	SELECT 1	The SQL query that will be used to validate connections from this pool before returning them to the caller or pool. If specified, this query does not have to return any data, it just can’t throw a SQLException.( FireBird will throw exception unless validationQuery set to select 1 from rdb$database)
validationQueryTimeout	none	The timeout before a connection validation queries fail.
checkConnectionWhileIdle	true	Set to true if query validation should take place while the connection is idle.
checkConnectionOnBorrow	false	Whether or not connections will be validated before being borrowed from the pool. If the connection fails to validate, it will be dropped from the pool, and another will be borrowed.
checkConnectionOnConnect	false	Whether or not connections will be validated before being added to the pool. If the connection fails to validate, it won’t be added to the pool.
checkConnectionOnReturn	false	Whether or not connections will be validated after being returned to the pool. If the connection fails to validate, it will be dropped from the pool.
autoCommentsEnabled	true	Whether or not ORMs should automatically add comments.
evictionInterval	5 seconds	The amount of time to sleep between runs of the idle connection validation, abandoned cleaner and idle pool resizing.
validationInterval	30 seconds	To avoid excess validation, only run validation once every interval.
validatorClassName	none	Name of a class of a custom validator implementation, which will be used for validating connections.
jdbcInterceptors	none	A semicolon separated list of JDBC interceptor classnames.
ignoreExceptionOnPreLoad	false	Flag whether ignore error of connection creation while initializing the pool. Set to true if you want to ignore error of connection creation while initializing the pool. Set to false if you want to fail the initialization of the pool by throwing exception.

Polymorphic configuration

The dropwizard-configuration module provides you with a polymorphic configuration mechanism, meaning that a particular section of your configuration file can be implemented using one or more configuration classes.

To use this capability for your own configuration classes, create a top-level configuration interface or class that implements Discoverable and add the name of that class to META-INF/services/io.dropwizard.jackson.Discoverable. Make sure to use Jackson polymorphic deserialization annotations appropriately.

@JsonTypeInfo(use = Id.NAME, include = As.PROPERTY, property = "type")
interface WidgetFactory extends Discoverable {
    Widget createWidget();
}

Then create subtypes of the top-level type corresponding to each alternative, and add their names to META-INF/services/WidgetFactory.

@JsonTypeName("hammer")
public class HammerFactory implements WidgetFactory {
    @JsonProperty
    private int weight = 10;

    @Override
    public Hammer createWidget() {
        return new Hammer(weight);
    }
}

@JsonTypeName("chisel")
public class ChiselFactory implements WidgetFactory {
    @JsonProperty
    private float radius = 1;

    @Override
    public Chisel createWidget() {
        return new Chisel(radius);
    }
}

Now you can use WidgetFactory objects in your application’s configuration.

public class MyConfiguration extends Configuration {
    @JsonProperty
    @NotNull
    @Valid
    private List<WidgetFactory> widgets;
}

widgets:
  - type: hammer
    weight: 20
  - type: chisel
    radius: 0.4

See testing configurations for details on ensuring the configuration will be deserialized correctly.