reference.conf

  #
  # Schedoscope configuration properties and default values
  #

  schedoscope {

    #
    # Basic settings
    #

    app {

      #
      # The environment name of your Schedoscope instance. This allows you to run
      # multiple instances of schedoscope, such as for development, testing or
      # production but also for different applications / datawarehouses.
      #
      # The environment impacts the default database and partition path naming
      # schemes.
      #
      # Common environment names are: dev, int, prod
      #

      environment = "dev"

      #
      # View augmentor (a class extending
      # org.schedoscope.dsl.views.ViewUrlParser.ParsedViewAugmentor)
      # to use for dynamic view instantiation via the view pattern URL scheme.
      # This can be used to modify instantiated views in application-specific
      # ways outside of view pattern URLs. Should rarely need change.
      #

      parsedViewAugmentorClass = "org.schedoscope.dsl.views.NoAugmentation"
    }

    #
    # Settings with regard to scheduling logic
    #

    scheduler {

      #
      # The earliest date to consider for MonthlyParameterization or
      # DailyParameterization view traits. Should be the earliest day you have
      # data for your application to avoid any needless no-data overhead.
      #

      earliestDay = "2013-12-01"

      #
      # The latest date to consider for MonthlyParameterization or
      # DailyParameterization view traits. Should usually be "now", but can be
      # reduced to a fixed date, for example in testing environments.
      #

      latestDay = "now"


      #
      # Various timeouts to obey
      #

      timeouts {

        #
        # Timeout waiting for metastore operations
        #

        schema = 30 minutes


        #
        # Timeout waiting for scheduling command to return
        #

        schedulingCommand = 30 minutes
      }

      #
      # Registered listeners for view scheduling state changes
      #

      viewSchedulingListeners = ["org.schedoscope.scheduler.listeners.ViewSchedulingMonitor"]

    }

    #
    # Configuration properties with regard Schedoscope's REST web service API.
    # Used for both Schedoscope server and the Schedoscope client tool.
    #

    webservice {


      #
      # Host where Schedoscope instance is running
      #

      host = "localhost"

      #
      # Port on which the Schedoscope web service listens for connections
      #

      port = 20698

      #
      # Directory for storing static web service resources
      #

      resourceDirectory = "www"

      #
      # Number of webservice actors to answer requests.
      #

      concurrency = 5
    }


    #
    # Kerberos-related settings
    #

    kerberos {

      #
      # The kerberos principal required for access to the Metastore
      # E.g.: hive/somemachine@SOMEDOMAIN.COM
      #
      principal = ""
    }

    #
    # Settings related to core Hadoop
    #

    hadoop {

      #
      # Address and port of the YARN resource manager. Note that any locally configured Hadoop environment
      # takes precedence.
      #

      resourceManager = "localhost:8032"

      #
      # Address and port of the HDFS namenode. Note that any locally configured Hadoop environment
      # takes precedence.
      #

      nameNode = "localhost:8020"

      #
      # HDFS URI
      #

      hdfs = "hdfs://localhost:8020"

      #
      # Schedoscope stores view data by default below this root folder.
      #

      viewDataHdfsRoot = "/hdp"
    }


    #
    # Settings related to dev environment
    #

    development {

      #
      # Enables the development feature
      #
      enabled = false

      #
      # Adress of the production namenode
      #
      prodNameNode = "locahost:8020"

      #
      # The environment under prod
      #
      prodEnv = "prod"

      #
      # Hdfs root on prod
      #
      prodViewDataHdfsRoot = "/hdp"

      #
      # Enables the usage of ssh to run the distcp on a remote machine
      #
      sshEnabled = false

      #
      # Ssh to this machine. Only needed if ssh is enabled
      #
      sshTarget = ""

      #
      # Views under development i.e. views which dependencies will be stubbed
      # by loading data from the prod environment.
      #
      # You can define one view or a list of views.
      #
      # e.g.: [ schedoscope.example.osm.datamart/ShopProfiles ]
      #
      viewUrls = [""]

    }

    #
    # Settings related to the Hive metastore
    #

    metastore {

      #
      # Thrift URI to metastore service
      #
      metastoreUri = "thrift://localhost:9083"

      #
      # Hive JDBC URL to connect to Hive Server 2
      #

      jdbcUrl = "jdbc:hive2://localhost:10000/default"

      #
      # Path to hive config files on your cluster
      #

      hiveConfDir = "/etc/hive/conf/"

      #
      # Number of parallel connections to use for schema- and partition creation
      # via the Hive metastore
      #

      concurrency = 5

      #
      # Back-off slot time (millis) for Actors dealing with metastore
      #
      actor-backoff-slot-time = 20000

      #
      # Back-off minimum constant delay (millis) for Actors dealing with metastore
      #
      actor-backoff-minimum-delay = 20000

      #
      # Number of partitions to put into a batch for each connection when
      # creating partitions
      #

      writeBatchSize = 2500

      #
      # Number of partitions to read in batch with each request on each
      # connection
      #

      readBatchSize = 10000
    }

    #
    # Settings concerning automatic logic change detection
    #

    versioning {

      #
      # Compute transformation version checksums and detect need for
      # rematerialization based on those checksums. Should be kept as is.
      #

      transformations = true
    }

    #
    # Number of retries for transformations before view state is changed to
    # failed.
    #

    action.retry = 5

    #
    # Setting concerning the usage of external dependencies
    #

    external-dependencies {

      #
      # This setting allows you to use external dependencies and operate several schedoscope instances in conjunction.
      #

      enabled = false

      #
      # A list of prefixes of packages with internal views. Every package not starting with a string in this list
      # will be treated as external and can not be referenced from the client or used as dependency if not flagged as
      # exernal
      #

      home = ["${env}.test.datahub"]

      #
      # Toggles checks whether internal views are used as external views and vice versa
      #

      checks = true
    }

    #
    # Default settings for exportTo() exporters.
    #

    export {

      #
      # Export settings for all export types
      #

      salt = "vD75MqvaasIlCf7H"

      #
      # BigQuery exporter settings.
      #

      bigQuery {

        #
        # GCP project ID under which the exported BigQuery dataset will be created
        #

        projectId = ""

        #
        # GCP key in JSON format to use for authentication
        #

        gcpKey = ""

        #
        # Number of reducers to use for parallel writing to BigQuery.
        #

        numberOfReducers = 10

        #
        # GCP data storage location of exported data within BigQuery.
        #

        dataLocation = "EU"

        #
        # GCP Cloud Storage bucket for temporary storage to use for exporting to BigQuery.
        #

        exportStorageBucket = "schedoscope_bigquery_export"

        #
        # GCP Cloud Storage bucket folder prefix to apply to blobs when exporting to BigQuery
        #

        exportStorageBucketFolderPrefix = ""

        #
        # GCP Cloud Storage bucket region to use for exporting to BigQuery
        #

        exportStorageBucketRegion = "europe-west3"

        #
        # Host of proxy to use for GCP API access
        #

        proxyHost = ""

        #
        # Port of proxy to use for GCP API access
        #

        proxyPort = ""


      }

      #
      # JDBC exporter settings.
      #

      jdbc {

        #
        # Number of reducers to use for parallel writing to JDBC.
        #

        numberOfReducers = 10

        #
        # Batch size for insert statements to use
        #

        insertBatchSize = 10000

        #
        # Storage engine to use (in case of MySQL JDBC targets)
        #

        storageEngine = "InnoDB"

      }

      #
      # Redis exporter.
      #

      redis {

        #
        # Number of reducers to use for parallel writing to Redis.
        #

        numberOfReducers = 10

        #
        # Usage of pipeline mode for writing to Redis.
        #

        usePipelineMode = false

        #
        # Batch size for Redis pipeline mode
        #

        insertBatchSize = 10000

      }

      #
      # Kafka exporter
      #

      kafka {

        #
        # Number of reducer to use for parallel writing to Kafka.
        #

        numberOfReducers = 10

      }

      #
      # Ftp exporter
      #

      ftp {

        #
        # Number of reducers to use for parallel exporting to a (S)Ftp Server.
        #

        numberOfReducers = 2

      }
    }

    #
    # Metascope related settings
    #

    metascope {

      #
      # Metascope webservice port
      #

      port = 8080

      #
      # The Schedoscope instance(s) webservice to retrieve the metadata from
      #

      schedoscope-instances = [
        {
          id = "schedoscope-1"
          host = "localhost"
          port = 20698
        }
      ]

      #
      # Configure authentication method
      #

      auth {

        #
        # Possible methods = ["simple", "ldap"]
        # simple: custom user management
        # ldap: external ldap directory is used for authentication
        #

        authentication = "simple"

        #
        # ldap settings
        #

        ldap {

          #
          # ldap server url
          #

          url = ""

          #
          #	ldap manager dn
          #

          managerDn = ""

          #
          # ldap manager password
          #

          managerPassword = ""

          #
          # ldap user dn pattern
          #

          userDnPattern = ""

          #
          # ldap group search base
          #

          groupSearchBase = ""

          #
          # Allowed groups to access Metascope
          #

          allowedGroups = ""

          #
          #	Admin group(s): User will have admin rights
          #

          adminGroups = ""

        }

      }

      #
      # Database which is used as the metadata repository.
      # Default: embedded Apache Derby instance, which creates a local repository in the metascope directory ('.../metascope/repository')
      #

      repository {

        #
        # JDBC URL to database server
        #

        url = "jdbc:h2:{metascope.dir}/repository;MODE=MySQL;CREATE=TRUE"

        #
        # database user
        #

        user = "sa"

        #
        # users password
        #

        password = "sa"

        #
        # Dialect to use to talk to database. For further information, visit:
        # http://docs.jboss.org/hibernate/orm/3.5/javadocs/org/hibernate/dialect/package-summary.html
        #

        dialect = "org.hibernate.dialect.H2Dialect"
      }

      #
      # Configure Hive Metastore access
      #

      metastore {

        #
        # Different ways to access metastore (only "thrift" and "jdbc" are allowed
        # "jdbc" mode only works with MySQL. When using "jdbc" mode, the metastore is accessed directly via JDBC
        #

        method = "thrift"

        jdbc {

          #
          # JDBC url to Hive Metastore (MySQL only)
          #

          url = ""

          #
          # database user to access metastore
          #

          user = ""

          #
          # database user password
          #

          password = ""

        }

      }

      #
      # Settigns relataed to the Apache Solr instance
      #

      solr {

        #
        # URL to Solr instance.
        # Default: embedded Apache Solr instance, which creates a local index in the metascope directory ('.../metascope/solr')
        #

        url = "{metascope.dir}/solr"
      }

      #
      # General settings concerning logging (via SLF4J)
      #

      logging {

        #
        # Path to logfile
        #

        logfile = "{metascope.dir}/logs/metascope-service.log"

        #
        # Log level granularity
        #

        loglevel = "DEBUG"
      }

    }

    #
    # Driver settings for the different transformation types.
    #

    transformations = {

      noop: {
        #
        # Class implementing the NoOp driver
        #
        driverClassName = "org.schedoscope.scheduler.driver.NoOpDriver"

        #
        # ignored
        #
        location = "/tmp/schedoscope/noop/"

        #
        # concurrency for NoOp transformations
        #
        concurrency = 5

        #
        # Back-off slot time (millis) for Driver Actor responsible
        #
        driver-actor-backoff-slot-time = 200

        #
        # Back-off minimum constant delay (millis) for Driver Actor responsible
        #
        driver-actor-backoff-minimum-delay = 100

        #
        # Timeout for NoOp transformations.
        #

        timeout = 1 day

        #
        # The handlers being notified after each driver run has
        # finished (succeeded or failed). These must implement the
        # trait org.schedoscope.scheduler.driver.DriverRunCompletionHandler
        #

        driverRunCompletionHandlers = ["org.schedoscope.scheduler.driver.DoNothingCompletionHandler"]

      }

      #
      # Settings for Hive transformations
      #

      hive: {

        #
        # Class implementing the Hive driver
        #

        driverClassName = "org.schedoscope.scheduler.driver.HiveDriver"

        #
        # Location where to put Hive UDFS in HDFS
        #

        location = "/tmp/schedoscope/hive/"

        #
        # Comma-separated list of directories where additional UDF library
        # jars can be found that are to be put onto HDFS when launching
        # Schedoscope.
        #

        libDirectory = ""

        #
        # Ignored
        #

        url = ""

        #
        # Do not change. Hive UDF jars should not be unpacked in HDFS.
        #

        unpack = false

        #
        # Number of parallel Driver actors to use for executing Hive
        # transformations
        #

        concurrency = 10

        #
        # Back-off slot time (millis) for Driver Actor responsible
        #
        driver-actor-backoff-slot-time = 5000

        #
        # Back-off minimum constant delay (millis) for Driver Actor responsible
        #
        driver-actor-backoff-minimum-delay = 3000

        #
        # Timeout for Hive transformations.
        #

        timeout = 1 day

        #
        # The handlers being notified after each driver run has
        # finished (succeeded or failed). These must implement the
        # trait org.schedoscope.scheduler.driver.DriverRunCompletionHandler
        #

        driverRunCompletionHandlers = ["org.schedoscope.scheduler.driver.DoNothingCompletionHandler"]

      },

      #
      # Settings for MapReduce transformations
      #

      mapreduce: {

        #
        # Class implementing the Mapreduce driver
        #

        driverClassName = "org.schedoscope.scheduler.driver.MapreduceDriver"

        #
        # Ignored.
        #

        location = "/tmp/schedoscope/mapreduce/"


        #
        # Ignored.
        #

        libDirectory = ""

        #
        # Ignored.
        #

        url = ""

        #
        # Ignored
        #

        unpack = false

        #
        # Number of parallel Driver actors to use for executing MapReduce
        # transformations
        #

        concurrency = 10

        #
        # Back-off slot time (millis) for Driver Actor responsible
        #
        driver-actor-backoff-slot-time = 5000

        #
        # Back-off minimum constant delay (millis) for Driver Actor responsible
        #
        driver-actor-backoff-minimum-delay = 3000

        #
        # Timeout for MapReduce transformations
        #

        timeout = 1 day

        #
        # The handlers being notified after each driver run has
        # finished (succeeded or failed). These must implement the
        # trait org.schedoscope.scheduler.driver.DriverRunCompletionHandler
        #

        driverRunCompletionHandlers = ["org.schedoscope.scheduler.driver.DoNothingCompletionHandler"]

      },

      #
      # File system driver settings
      #

      filesystem: {

        #
        # Class implementing the FileSystem driver
        #

        driverClassName = "org.schedoscope.scheduler.driver.FilesystemDriver"

        #
        # Number of parallel Driver actors to use for executing file system
        # transformations
        #

        concurrency = 1

        #
        # Back-off slot time (millis) for Driver Actor responsible
        #
        driver-actor-backoff-slot-time = 200

        #
        # Back-off minimum constant delay (millis) for Driver Actor responsible
        #
        driver-actor-backoff-minimum-delay = 100

        #
        # Ignored.
        #

        location = "/tmp/schedoscope/filesystem/"

        #
        # Ignored
        #

        libDirectory = ""

        #
        # Ignored
        #

        url = ""

        #
        # Ignored
        #

        unpack = false

        #
        # Timeout for file system transformations
        #

        timeout = 1 hour

        #
        # The handlers being notified after each driver run has
        # finished (succeeded or failed). These must implement the
        # trait org.schedoscope.scheduler.driver.DriverRunCompletionHandler
        #

        driverRunCompletionHandlers = ["org.schedoscope.scheduler.driver.DoNothingCompletionHandler"]

      },

      #
      # Sequence driver settings
      #

      seq: {

        #
        # Class implementing the Seq driver
        #

        driverClassName = "org.schedoscope.scheduler.driver.SeqDriver"

        #
        # Number of parallel Driver actors to use for executing seq
        # transformations
        #

        concurrency = 10

        #
        # Back-off slot time (millis) for Driver Actor responsible
        #
        driver-actor-backoff-slot-time = 200

        #
        # Back-off minimum constant delay (millis) for Driver Actor responsible
        #
        driver-actor-backoff-minimum-delay = 100

        #
        # Ignored.
        #

        location = "/tmp/schedoscope/seq/"

        #
        # Ignored
        #

        libDirectory = ""

        #
        # Ignored
        #

        url = ""

        #
        # Ignored
        #

        unpack = false

        #
        # Timeout for seq transformations
        #

        timeout = 1 day

        #
        # The handlers being notified after each driver run has
        # finished (succeeded or failed). These must implement the
        # trait org.schedoscope.scheduler.driver.DriverRunCompletionHandler
        #

        driverRunCompletionHandlers = ["org.schedoscope.scheduler.driver.DoNothingCompletionHandler"]

      }

      #
      # Shell driver settings
      #

      shell: {

        #
        # Class implementing the Shell driver
        #

        driverClassName = "org.schedoscope.scheduler.driver.ShellDriver"

        #
        # Number of parallel Shell Driver actors to use
        #

        concurrency = 1

        #
        # Back-off slot time (millis) for Driver Actor responsible
        #
        driver-actor-backoff-slot-time = 200

        #
        # Back-off minimum constant delay (millis) for Driver Actor responsible
        #
        driver-actor-backoff-minimum-delay = 0

        #
        # Ignored
        #

        location = "/tmp/schedoscope/shell/"

        #
        # Ignored
        #

        libDirectory = ""

        #
        # Ignored
        #

        url = ""

        #
        # Ignored
        #

        unpack = false

        #
        # Timeout for Shell transformations
        #

        timeout = 1 day

        #
        # The handlers being notified after each driver run has
        # finished (succeeded or failed). These must implement the
        # trait org.schedoscope.scheduler.driver.DriverRunCompletionHandler
        #

        driverRunCompletionHandlers = ["org.schedoscope.scheduler.driver.DoNothingCompletionHandler"]
      }
    }

    test {
      disableLineageValidation = true
    }

  }

  #
  # This section covers general Akka settings, in particular concerning the
  # various dispatchers / threadpools.
  #

  akka {

    #
    # General settings concerning logging (via SLF4J). Logback is given as a
    # default dependency to Schedoscope so SLF4J via Logback is the default
    # logging system.
    #

    log-config-on-start = off
    log-dead-letters = off
    loglevel = "INFO"
    loggers = ["akka.event.slf4j.Slf4jLogger"]

    #
    # Dispatcher settings
    #

    actor {

      guardian-supervisor-strategy = "org.schedoscope.TerminatingStoppingStrategy"

      #
      # Given the variety of component-specific dispatchers used by Schedoscope
      # we limit the Akka default dispatcher to 4 threads.
      #

      default-dispatcher {
        executor = "thread-pool-executor"
        type = Dispatcher

        thread-pool-executor {
          core-pool-size-min = 4
          core-pool-size-factor = 1.0
          core-pool-size-max = 4
          task-queue-size = -1
        }

        throughput = 5
      }


      #
      # Configuration of threads to use for unspecific future calls and
      # computations.
      # Again limited.
      #

      future-call-dispatcher {
        type = Dispatcher
        executor = "thread-pool-executor"

        thread-pool-executor {
          core-pool-size-min = 8
          core-pool-size-factor = 2.0
          core-pool-size-max = 8
          task-queue-size = -1
        }

        throughput = 5
      }


      #
      # The supervisor / message router for the Metastore-related actors is
      # assigned to one pinned dispatcher / thread. Should not need to be
      # changed.
      #

      schema-manager-dispatcher {
        executor = "thread-pool-executor"
        type = PinnedDispatcher
      }

      #
      # Threadpool / dispatcher configuration for the actor communicating
      # with the Metastore for creating / reading tables and partitions. Should
      # be aligned with the property schedoscope.metastore.concurrency
      #

      partition-creator-dispatcher {
        executor = "thread-pool-executor"
        type = Dispatcher
        mailbox-type = "org.schedoscope.scheduler.actors.ManagedActorPriorityMailbox"

        thread-pool-executor {
          core-pool-size-min = 5
          core-pool-size-factor = 1.0
          core-pool-size-max = 5
          task-queue-size = -1
        }

        throughput = 5
      }


      #
      # The actor logging transformation metadata (version, timestamp) to the
      # Metastore has one dedicated pinned dispatcher / thread.
      #

      metadata-logger-dispatcher {
        executor = "thread-pool-executor"
        type = PinnedDispatcher
        mailbox-type = "org.schedoscope.scheduler.actors.ManagedActorPriorityMailbox"
      }

      #
      # The actor managing, assigning, and collecting status information about
      # transformations to execute has one dedicated pinned dispatcher / thread
      # for reasons of responsiveness.
      #

      transformation-manager-dispatcher {
        executor = "thread-pool-executor"
        type = PinnedDispatcher
      }

      #
      # The actor managing and instantiating view actors for scheduling state
      # management has one dedicated pinned dispatcher / thread for reasons of
      # responsiveness.
      #

      view-manager-dispatcher {
        executor = "thread-pool-executor"
        type = PinnedDispatcher
      }

      #
      # The threadpool / dispatcher used by the table actors for communicating
      # with each other for view materialization and scheduling.
      #

      views-dispatcher {
        executor = "fork-join-executor"
        type = Dispatcher

        fork-join-executor {
          parallelism-min = 8
          parallelism-factor = 2.0
          parallelism-max = 8
          task-queue-size = -1
        }

        throughput = 5
      }

      #
      # The Router actor managing and instantiating driver actors
      # has one dedicated pinned dispatcher / thread for reasons of
      # responsiveness.
      #

      driver-router-dispatcher {
        executor = "thread-pool-executor"
        type = PinnedDispatcher
      }

      #
      # The threadpool / dispatcher available for the transformation drivers.
      # As drivers execute transformations asynchronously - either by
      # communicating with servers like Oozie or the Resource Manager or by
      # futures, this pool should not need to grow much when increasing
      # concurrency settings of the various transformations.
      #

      driver-dispatcher {
        executor = "thread-pool-executor"
        type = Dispatcher
        mailbox-type = "org.schedoscope.scheduler.actors.ManagedActorPriorityMailbox"

        thread-pool-executor {
          core-pool-size-min = 8
          core-pool-size-factor = 2.0
          core-pool-size-max = 8
          task-queue-size = -1
        }

        throughput = 5
      }

      #
      # Due to API limitations, we can currently only execute file system, Pig,
      # and Hive transformations asynchronously by employing futures.
      #
      # The following threadpool / dispatcher feeds those futures. Hence, it
      # should grow proportionally with the concurrency settings of the
      # mentioned transformation types.
      #

      future-driver-dispatcher {
        type = Dispatcher
        executor = "thread-pool-executor"

        thread-pool-executor {
          core-pool-size-min = 16
          core-pool-size-factor = 4.0
          core-pool-size-max = 16
          task-queue-size = -1
        }

        throughput = 5
      }

      #
      # The Supervising strategy for view scheduling Listener Actors
      # maxRetries - maximum number of restart attempts for OneForOneStrategy
      #
      view-scheduling-listener-actor {
        maxRetries = -1
      }

    }
  }

  #
  # The following are a list of "suggestions" for spray settings to use for the
  # Schedoscope web service and client. They are not automatically pulled
  # but have to be explicitly set in your application.conf / schedoscope.conf.
  #

  spray.can {
    client {
      parsing {
        max-content-length = 100m
      }

      # The time after which an idle connection will be automatically closed.
      # Set to `infinite` to completely disable idle timeouts.
      idle-timeout = 1200s

      #  The max time period that a client connection will be waiting for a response
      #  before triggering a request timeout. The timer for this logic is not started
      #  until the connection is actually in a state to receive the response, which
      #  may be quite some time after the request has been received from the
      #  application!
      #  There are two main reasons to delay the start of the request timeout timer:
      #    1. On the host-level API with pipelining disabled:
      #  If the request cannot be sent immediately because all connections are
      #  currently busy with earlier requests it has to be queued until a
      #  connection becomes available.
      #  2. With pipelining enabled:
      #    The request timeout timer starts only once the response for the
      #  preceding request on the connection has arrived.
      #  Set to `infinite` to completely disable request timeouts.
      request-timeout = 900s

      # The time period within which the TCP connecting process must be completed.
      # Set to `infinite` to disable.
      connecting-timeout = 10s

    }
    server {
      # If a request hasn't been responded to after the time period set here
      # a `spray.http.Timedout` message will be sent to the timeout handler.
      # Set to `infinite` to completely disable request timeouts.
      request-timeout = 900s

      # After a `Timedout` message has been sent to the timeout handler and the
      # request still hasn't been completed after the time period set here
      # the server will complete the request itself with an error response.
      # Set to `infinite` to disable timeout timeouts.
      timeout-timeout = 6s

      # The time after which an idle connection will be automatically closed.
      # Set to `infinite` to completely disable idle connection timeouts.
      idle-timeout = 1200s

      # Enables/disables the returning of more detailed error messages to
      # the client in the error response.
      # Should be disabled for browser-facing APIs due to the risk of XSS attacks
      # and (probably) enabled for internal or non-browser APIs.
      # Note that spray will always produce log messages containing the full
      # error details.
      verbose-error-messages = off

      # Enables/disables the logging of the full (potentially multiple line)
      # error message to the server logs.
      # If disabled only a single line will be logged.
      verbose-error-logging = off

      # Enables/disables support for statistics collection and querying.
      # Even though stats keeping overhead is small,
      # for maximum performance switch off when not needed.
      stats-support = on

      # Enables/disables automatic back-pressure handling by write buffering and
      # receive throttling
      automatic-back-pressure-handling = on
      back-pressure {
        # The reciprocal rate of requested Acks per NoAcks. E.g. the default value
        # '10' means that every 10th write request is acknowledged. This affects the
        # number of writes each connection has to buffer even in absence of back-pressure.
        noack-rate = 10
        # The lower limit the write queue size has to shrink to before reads are resumed.
        # Use 'infinite' to disable the low-watermark so that reading is resumed instantly
        # after the next successful write.
        reading-low-watermark = infinite
      }
    }
  }