apm-server.reference.yml

################### APM Server Configuration Example #########################

############################# APM Server ######################################

apm-server:
  # Defines the host and port the server is listening on

  #host: "localhost:8200"
  #max_unzipped_size:
  #max_header_bytes:
  #read_timeout: 2s
  #write_timeout: 2s

  # Authorization token to be checked. If a token is set here the agents must
  # send their token in the following format: Authorization: Bearer <secret-token>
  #secret_token:

#================================ General ======================================

# The name of the shipper that publishes the network data. It can be used to group
# all the transactions sent by a single shipper in the web interface.
# If this options is not defined, the hostname is used.
#name:

# The tags of the shipper are included in their own field with each
# transaction published. Tags make it easy to group servers by different
# logical properties.
#tags: ["service-X", "web-tier"]

# Optional fields that you can specify to add additional information to the
# output. Fields can be scalar values, arrays, dictionaries, or any nested
# combination of these.
#fields:
#  env: staging

# If this option is set to true, the custom fields are stored as top-level
# fields in the output document instead of being grouped under a fields
# sub-dictionary. Default is false.
#fields_under_root: false

# Internal queue configuration for buffering events to be published.
#queue:
  # Queue type by name (default 'mem')
  # The memory queue will present all available events (up to the outputs
  # bulk_max_size) to the output, the moment the output is ready to server
  # another batch of events.
  #mem:
    # Max number of events the queue can buffer.
    #events: 4096

    # Hints the minimum number of events stored in the queue,
    # before providing a batch of events to the outputs.
    # A value of 0 (the default) ensures events are immediately available
    # to be sent to the outputs.
    #flush.min_events: 0

    # Maximum duration after which events are available to the outputs,
    # if the number of events stored in the queue is < min_flush_events.
    #flush.timeout: 0s

# Sets the maximum number of CPUs that can be executing simultaneously. The
# default is the number of logical CPUs available in the system.
#max_procs:

#================================ Processors ===================================

# Processors are used to reduce the number of fields in the exported event or to
# enhance the event with external metadata. This section defines a list of
# processors that are applied one by one and the first one receives the initial
# event:
#
#   event -> filter1 -> event1 -> filter2 ->event2 ...
#
# The supported processors are drop_fields, drop_event, include_fields, and
# add_cloud_metadata.
#
# For example, you can use the following processors to keep the fields that
# contain CPU load percentages, but remove the fields that contain CPU ticks
# values:
#
#processors:
#- include_fields:
#    fields: ["cpu"]
#- drop_fields:
#    fields: ["cpu.user", "cpu.system"]
#
# The following example drops the events that have the HTTP response code 200:
#
#processors:
#- drop_event:
#    when:
#       equals:
#           http.code: 200
#
# The following example enriches each event with metadata from the cloud
# provider about the host machine. It works on EC2, GCE, DigitalOcean,
# Tencent Cloud, and Alibaba Cloud.
#
#processors:
#- add_cloud_metadata: ~
#
# The following example enriches each event with the machine's local time zone
# offset from UTC.
#
#processors:
#- add_locale:
#    format: offset
#
# The following example enriches each event with docker metadata, it matches
# given fields to an existing container id and adds info from that container:
#
#processors:
#- add_docker_metadata:
#    host: "unix:///var/run/docker.sock"
#    match_fields: ["system.process.cgroup.id"]
#    # To connect to Docker over TLS you must specify a client and CA certificate.
#    #ssl:
#    #  certificate_authority: "/etc/pki/root/ca.pem"
#    #  certificate:           "/etc/pki/client/cert.pem"
#    #  key:                   "/etc/pki/client/cert.key"
#
# The following example enriches each event with docker metadata, it matches
# container id from log path available in `source` field (by default it expects
# it to be /var/lib/docker/containers/*/*.log).
#
#processors:
#- add_docker_metadata: ~

#============================= Elastic Cloud ==================================

# These settings simplify using apm-server with the Elastic Cloud (https://cloud.elastic.co/).

# The cloud.id setting overwrites the `output.elasticsearch.hosts` and
# `setup.kibana.host` options.
# You can find the `cloud.id` in the Elastic Cloud web UI.
#cloud.id:

# The cloud.auth setting overwrites the `output.elasticsearch.username` and
# `output.elasticsearch.password` settings. The format is `<user>:<pass>`.
#cloud.auth:

#================================ Outputs ======================================

# Configure what outputs to use when sending the data collected by the beat.
# Multiple outputs may be used.

#-------------------------- Elasticsearch output -------------------------------
output.elasticsearch:
  # Boolean flag to enable or disable the output module.
  #enabled: true

  # Array of hosts to connect to.
  # Scheme and port can be left out and will be set to the default (http and 9200)
  # In case you specify and additional path, the scheme is required: http://localhost:9200/path
  # IPv6 addresses should always be defined as: https://[2001:db8::1]:9200
  hosts: ["localhost:9200"]

  # Set gzip compression level.
  #compression_level: 0

  # Optional protocol and basic auth credentials.
  #protocol: "https"
  #username: "elastic"
  #password: "changeme"

  # Dictionary of HTTP parameters to pass within the url with index operations.
  #parameters:
    #param1: value1
    #param2: value2

  # Number of workers per Elasticsearch host.
  #worker: 1

  # Optional index name. The default is "apm-server" plus date
  # and generates [apm-server-]YYYY.MM.DD keys.
  # In case you modify this pattern you must update setup.template.name and setup.template.pattern accordingly.
  #index: "apm-server-%{[beat.version]}-%{+yyyy.MM.dd}"

  # Optional ingest node pipeline. By default no pipeline will be used.
  #pipeline: ""

  # Optional HTTP Path
  #path: "/elasticsearch"

  # Custom HTTP headers to add to each request
  #headers:
  #  X-My-Header: Contents of the header

  # Proxy server url
  #proxy_url: http://proxy:3128

  # The number of times a particular Elasticsearch index operation is attempted. If
  # the indexing operation doesn't succeed after this many retries, the events are
  # dropped. The default is 3.
  #max_retries: 3

  # The maximum number of events to bulk in a single Elasticsearch bulk API index request.
  # The default is 50.
  #bulk_max_size: 50

  # Configure http request timeout before failing an request to Elasticsearch.
  #timeout: 90

  # Use SSL settings for HTTPS. Default is true.
  #ssl.enabled: true

  # Configure SSL verification mode. If `none` is configured, all server hosts
  # and certificates will be accepted. In this mode, SSL based connections are
  # susceptible to man-in-the-middle attacks. Use only for testing. Default is
  # `full`.
  #ssl.verification_mode: full

  # List of supported/valid TLS versions. By default all TLS versions 1.0 up to
  # 1.2 are enabled.
  #ssl.supported_protocols: [TLSv1.0, TLSv1.1, TLSv1.2]

  # SSL configuration. By default is off.
  # List of root certificates for HTTPS server verifications
  #ssl.certificate_authorities: ["/etc/pki/root/ca.pem"]

  # Certificate for SSL client authentication
  #ssl.certificate: "/etc/pki/client/cert.pem"

  # Client Certificate Key
  #ssl.key: "/etc/pki/client/cert.key"

  # Optional passphrase for decrypting the Certificate Key.
  #ssl.key_passphrase: ''

  # Configure cipher suites to be used for SSL connections
  #ssl.cipher_suites: []

  # Configure curve types for ECDHE based cipher suites
  #ssl.curve_types: []


#----------------------------- Logstash output ---------------------------------
#output.logstash:
  # Boolean flag to enable or disable the output module.
  #enabled: true

  # The Logstash hosts
  #hosts: ["localhost:5044"]

  # Number of workers per Logstash host.
  #worker: 1

  # Set gzip compression level.
  #compression_level: 3

  # Optional maximum time to live for a connection to Logstash, after which the
  # connection will be re-established.  A value of `0s` (the default) will
  # disable this feature.
  #
  # Not yet supported for async connections (i.e. with the "pipelining" option set)
  #ttl: 30s

  # Optional load balance the events between the Logstash hosts
  #loadbalance: true

  # Number of batches to be sent asynchronously to logstash while processing
  # new batches.
  #pipelining: 5

  # Optional index name. The default index name is set to name of the beat
  # in all lowercase.
  #index: 'apm-server'

  # SOCKS5 proxy server URL
  #proxy_url: socks5://user:password@socks5-server:2233

  # Resolve names locally when using a proxy server. Defaults to false.
  #proxy_use_local_resolver: false

  # Enable SSL support. SSL is automatically enabled, if any SSL setting is set.
  #ssl.enabled: true

  # Configure SSL verification mode. If `none` is configured, all server hosts
  # and certificates will be accepted. In this mode, SSL based connections are
  # susceptible to man-in-the-middle attacks. Use only for testing. Default is
  # `full`.
  #ssl.verification_mode: full

  # List of supported/valid TLS versions. By default all TLS versions 1.0 up to
  # 1.2 are enabled.
  #ssl.supported_protocols: [TLSv1.0, TLSv1.1, TLSv1.2]

  # Optional SSL configuration options. SSL is off by default.
  # List of root certificates for HTTPS server verifications
  #ssl.certificate_authorities: ["/etc/pki/root/ca.pem"]

  # Certificate for SSL client authentication
  #ssl.certificate: "/etc/pki/client/cert.pem"

  # Client Certificate Key
  #ssl.key: "/etc/pki/client/cert.key"

  # Optional passphrase for decrypting the Certificate Key.
  #ssl.key_passphrase: ''

  # Configure cipher suites to be used for SSL connections
  #ssl.cipher_suites: []

  # Configure curve types for ECDHE based cipher suites
  #ssl.curve_types: []

#------------------------------- Kafka output ----------------------------------
#output.kafka:
  # Boolean flag to enable or disable the output module.
  #enabled: true

  # The list of Kafka broker addresses from where to fetch the cluster metadata.
  # The cluster metadata contain the actual Kafka brokers events are published
  # to.
  #hosts: ["localhost:9092"]

  # The Kafka topic used for produced events. The setting can be a format string
  # using any event field. To set the topic from document type use `%{[type]}`.
  #topic: beats

  # The Kafka event key setting. Use format string to create unique event key.
  # By default no event key will be generated.
  #key: ''

  # The Kafka event partitioning strategy. Default hashing strategy is `hash`
  # using the `output.kafka.key` setting or randomly distributes events if
  # `output.kafka.key` is not configured.
  #partition.hash:
    # If enabled, events will only be published to partitions with reachable
    # leaders. Default is false.
    #reachable_only: false

    # Configure alternative event field names used to compute the hash value.
    # If empty `output.kafka.key` setting will be used.
    # Default value is empty list.
    #hash: []

  # Authentication details. Password is required if username is set.
  #username: ''
  #password: ''

  # Kafka version apm-server is assumed to run against. Defaults to the oldest
  # supported stable version (currently version 0.8.2.0)
  #version: 0.8.2

  # Metadata update configuration. Metadata do contain leader information
  # deciding which broker to use when publishing.
  #metadata:
    # Max metadata request retry attempts when cluster is in middle of leader
    # election. Defaults to 3 retries.
    #retry.max: 3

    # Waiting time between retries during leader elections. Default is 250ms.
    #retry.backoff: 250ms

    # Refresh metadata interval. Defaults to every 10 minutes.
    #refresh_frequency: 10m

  # The number of concurrent load-balanced Kafka output workers.
  #worker: 1

  # The number of times to retry publishing an event after a publishing failure.
  # After the specified number of retries, the events are typically dropped.
  # Some Beats, such as Filebeat, ignore the max_retries setting and retry until
  # all events are published.  Set max_retries to a value less than 0 to retry
  # until all events are published. The default is 3.
  #max_retries: 3

  # The maximum number of events to bulk in a single Kafka request. The default
  # is 2048.
  #bulk_max_size: 2048

  # The number of seconds to wait for responses from the Kafka brokers before
  # timing out. The default is 30s.
  #timeout: 30s

  # The maximum duration a broker will wait for number of required ACKs. The
  # default is 10s.
  #broker_timeout: 10s

  # The number of messages buffered for each Kafka broker. The default is 256.
  #channel_buffer_size: 256

  # The keep-alive period for an active network connection. If 0s, keep-alives
  # are disabled. The default is 0 seconds.
  #keep_alive: 0

  # Sets the output compression codec. Must be one of none, snappy and gzip. The
  # default is gzip.
  #compression: gzip

  # The maximum permitted size of JSON-encoded messages. Bigger messages will be
  # dropped. The default value is 1000000 (bytes). This value should be equal to
  # or less than the broker's message.max.bytes.
  #max_message_bytes: 1000000

  # The ACK reliability level required from broker. 0=no response, 1=wait for
  # local commit, -1=wait for all replicas to commit. The default is 1.  Note:
  # If set to 0, no ACKs are returned by Kafka. Messages might be lost silently
  # on error.
  #required_acks: 1

  # The configurable ClientID used for logging, debugging, and auditing
  # purposes.  The default is "beats".
  #client_id: beats

  # Enable SSL support. SSL is automatically enabled, if any SSL setting is set.
  #ssl.enabled: true

  # Optional SSL configuration options. SSL is off by default.
  # List of root certificates for HTTPS server verifications
  #ssl.certificate_authorities: ["/etc/pki/root/ca.pem"]

  # Configure SSL verification mode. If `none` is configured, all server hosts
  # and certificates will be accepted. In this mode, SSL based connections are
  # susceptible to man-in-the-middle attacks. Use only for testing. Default is
  # `full`.
  #ssl.verification_mode: full

  # List of supported/valid TLS versions. By default all TLS versions 1.0 up to
  # 1.2 are enabled.
  #ssl.supported_protocols: [TLSv1.0, TLSv1.1, TLSv1.2]

  # Certificate for SSL client authentication
  #ssl.certificate: "/etc/pki/client/cert.pem"

  # Client Certificate Key
  #ssl.key: "/etc/pki/client/cert.key"

  # Optional passphrase for decrypting the Certificate Key.
  #ssl.key_passphrase: ''

  # Configure cipher suites to be used for SSL connections
  #ssl.cipher_suites: []

  # Configure curve types for ECDHE based cipher suites
  #ssl.curve_types: []

#------------------------------- Redis output ----------------------------------
#output.redis:
  # Boolean flag to enable or disable the output module.
  #enabled: true

  # The list of Redis servers to connect to. If load balancing is enabled, the
  # events are distributed to the servers in the list. If one server becomes
  # unreachable, the events are distributed to the reachable servers only.
  #hosts: ["localhost:6379"]

  # The Redis port to use if hosts does not contain a port number. The default
  # is 6379.
  #port: 6379

  # The name of the Redis list or channel the events are published to. The
  # default is apm-server.
  #key: apm-server

  # The password to authenticate with. The default is no authentication.
  #password:

  # The Redis database number where the events are published. The default is 0.
  #db: 0

  # The Redis data type to use for publishing events. If the data type is list,
  # the Redis RPUSH command is used. If the data type is channel, the Redis
  # PUBLISH command is used. The default value is list.
  #datatype: list

  # The number of workers to use for each host configured to publish events to
  # Redis. Use this setting along with the loadbalance option. For example, if
  # you have 2 hosts and 3 workers, in total 6 workers are started (3 for each
  # host).
  #worker: 1

  # If set to true and multiple hosts or workers are configured, the output
  # plugin load balances published events onto all Redis hosts. If set to false,
  # the output plugin sends all events to only one host (determined at random)
  # and will switch to another host if the currently selected one becomes
  # unreachable. The default value is true.
  #loadbalance: true

  # The Redis connection timeout in seconds. The default is 5 seconds.
  #timeout: 5s

  # The number of times to retry publishing an event after a publishing failure.
  # After the specified number of retries, the events are typically dropped.
  # Some Beats, such as Filebeat, ignore the max_retries setting and retry until
  # all events are published. Set max_retries to a value less than 0 to retry
  # until all events are published. The default is 3.
  #max_retries: 3

  # The maximum number of events to bulk in a single Redis request or pipeline.
  # The default is 2048.
  #bulk_max_size: 2048

  # The URL of the SOCKS5 proxy to use when connecting to the Redis servers. The
  # value must be a URL with a scheme of socks5://.
  #proxy_url:

  # This option determines whether Redis hostnames are resolved locally when
  # using a proxy. The default value is false, which means that name resolution
  # occurs on the proxy server.
  #proxy_use_local_resolver: false

  # Enable SSL support. SSL is automatically enabled, if any SSL setting is set.
  #ssl.enabled: true

  # Configure SSL verification mode. If `none` is configured, all server hosts
  # and certificates will be accepted. In this mode, SSL based connections are
  # susceptible to man-in-the-middle attacks. Use only for testing. Default is
  # `full`.
  #ssl.verification_mode: full

  # List of supported/valid TLS versions. By default all TLS versions 1.0 up to
  # 1.2 are enabled.
  #ssl.supported_protocols: [TLSv1.0, TLSv1.1, TLSv1.2]

  # Optional SSL configuration options. SSL is off by default.
  # List of root certificates for HTTPS server verifications
  #ssl.certificate_authorities: ["/etc/pki/root/ca.pem"]

  # Certificate for SSL client authentication
  #ssl.certificate: "/etc/pki/client/cert.pem"

  # Client Certificate Key
  #ssl.key: "/etc/pki/client/cert.key"

  # Optional passphrase for decrypting the Certificate Key.
  #ssl.key_passphrase: ''

  # Configure cipher suites to be used for SSL connections
  #ssl.cipher_suites: []

  # Configure curve types for ECDHE based cipher suites
  #ssl.curve_types: []


#------------------------------- File output -----------------------------------
#output.file:
  # Boolean flag to enable or disable the output module.
  #enabled: true

  # Path to the directory where to save the generated files. The option is
  # mandatory.
  #path: "/tmp/apm-server"

  # Name of the generated files. The default is `apm-server` and it generates
  # files: `apm-server`, `apm-server.1`, `apm-server.2`, etc.
  #filename: apm-server

  # Maximum size in kilobytes of each file. When this size is reached, and on
  # every apm-server restart, the files are rotated. The default value is 10240
  # kB.
  #rotate_every_kb: 10000

  # Maximum number of files under path. When this number of files is reached,
  # the oldest file is deleted and the rest are shifted from last to first. The
  # default is 7 files.
  #number_of_files: 7


#----------------------------- Console output ---------------------------------
#output.console:
  # Boolean flag to enable or disable the output module.
  #enabled: true

  # Pretty print json event
  #pretty: false

#================================= Paths ======================================

# The home path for the apm-server installation. This is the default base path
# for all other path settings and for miscellaneous files that come with the
# distribution (for example, the sample dashboards).
# If not set by a CLI flag or in the configuration file, the default for the
# home path is the location of the binary.
#path.home:

# The configuration path for the apm-server installation. This is the default
# base path for configuration files, including the main YAML configuration file
# and the Elasticsearch template file. If not set by a CLI flag or in the
# configuration file, the default for the configuration path is the home path.
#path.config: ${path.home}

# The data path for the apm-server installation. This is the default base path
# for all the files in which apm-server needs to store its data. If not set by a
# CLI flag or in the configuration file, the default for the data path is a data
# subdirectory inside the home path.
#path.data: ${path.home}/data

# The logs path for a apm-server installation. This is the default location for
# the Beat's log files. If not set by a CLI flag or in the configuration file,
# the default for the logs path is a logs subdirectory inside the home path.
#path.logs: ${path.home}/logs

#============================== Dashboards =====================================
# These settings control loading the sample dashboards to the Kibana index. Loading
# the dashboards is disabled by default and can be enabled either by setting the
# options here, or by using the `-setup` CLI flag or the `setup` command.
#setup.dashboards.enabled: false

# The directory from where to read the dashboards. The default is the `kibana`
# folder in the home path.
#setup.dashboards.directory: ${path.home}/kibana

# The URL from where to download the dashboards archive. It is used instead of
# the directory if it has a value.
#setup.dashboards.url:

# The file archive (zip file) from where to read the dashboards. It is used instead
# of the directory when it has a value.
#setup.dashboards.file:

# In case the archive contains the dashboards from multiple Beats, this lets you
# select which one to load. You can load all the dashboards in the archive by
# setting this to the empty string.
#setup.dashboards.beat: apm-server

# The name of the Kibana index to use for setting the configuration. Default is ".kibana"
#setup.dashboards.kibana_index: .kibana

# The Elasticsearch index name. This overwrites the index name defined in the
# dashboards and index pattern. Example: testbeat-*
#setup.dashboards.index:

#============================== Template =====================================

# A template is used to set the mapping in Elasticsearch
# By default template loading is enabled and the template is loaded.
# These settings can be adjusted to load your own template or overwrite existing ones.

# Set to false to disable template loading.
#setup.template.enabled: true

# Template name. By default the template name is "apm-server-%{[beat.version]}"
# The template name and pattern has to be set in case the elasticsearch index pattern is modified.
#setup.template.name: "apm-server-%{[beat.version]}"

# Template patttern. By default the template patter is "-%{[beat.version]}-*" to apply to the default index settings.
# The first part is the version of the beat and then -* is used to match all daily indicies.
# The template name and pattern has to be set in case the elasticsearch index pattern is modified.
#setup.template.pattern: "apm-server-%{[beat.version]}-*"

# Path to fields.yml file to generate the template
#setup.template.fields: "${path.config}/fields.yml"

# Overwrite existing template
#setup.template.overwrite: false

# Elasticsearch template settings
setup.template.settings:

  # A dictionary of settings to place into the settings.index dictionary
  # of the Elasticsearch template. For more details, please check
  # https://www.elastic.co/guide/en/elasticsearch/reference/current/mapping.html
  #index:
    #number_of_shards: 1
    #codec: best_compression

  # A dictionary of settings for the _source field. For more details, please check
  # https://www.elastic.co/guide/en/elasticsearch/reference/current/mapping-source-field.html
  #_source:
    #enabled: false

#============================== Kibana =====================================

# Starting with Beats version 6.0.0, the dashboards are loaded via the Kibana API.
# This requires a Kibana endpoint configuration.
setup.kibana:

  # Kibana Host
  # Scheme and port can be left out and will be set to the default (http and 5601)
  # In case you specify and additional path, the scheme is required: http://localhost:5601/path
  # IPv6 addresses should always be defined as: https://[2001:db8::1]:5601
  #host: "localhost:5601"

  # Optional protocol and basic auth crendentials.
  #protocol: "https"
  #username: "elastic"
  #password: "changeme"

  # Optional HTTP Path
  #path: ""

  # Use SSL settings for HTTPS. Default is true.
  #ssl.enabled: true

  # Configure SSL verification mode. If `none` is configured, all server hosts
  # and certificates will be accepted. In this mode, SSL based connections are
  # susceptible to man-in-the-middle attacks. Use only for testing. Default is
  # `full`.
  #ssl.verification_mode: full

  # List of supported/valid TLS versions. By default all TLS versions 1.0 up to
  # 1.2 are enabled.
  #ssl.supported_protocols: [TLSv1.0, TLSv1.1, TLSv1.2]

  # SSL configuration. By default is off.
  # List of root certificates for HTTPS server verifications
  #ssl.certificate_authorities: ["/etc/pki/root/ca.pem"]

  # Certificate for SSL client authentication
  #ssl.certificate: "/etc/pki/client/cert.pem"

  # Client Certificate Key
  #ssl.key: "/etc/pki/client/cert.key"

  # Optional passphrase for decrypting the Certificate Key.
  #ssl.key_passphrase: ''

  # Configure cipher suites to be used for SSL connections
  #ssl.cipher_suites: []

  # Configure curve types for ECDHE based cipher suites
  #ssl.curve_types: []



#================================ Logging ======================================
# There are three options for the log output: syslog, file, stderr.
# Under Windows systems, the log files are per default sent to the file output,
# under all other system per default to syslog.

# Sets log level. The default log level is info.
# Available log levels are: critical, error, warning, info, debug
#logging.level: info

# Enable debug output for selected components. To enable all selectors use ["*"]
# Other available selectors are "beat", "publish", "service"
# Multiple selectors can be chained.
#logging.selectors: [ ]

# Send all logging output to syslog. The default is false.
#logging.to_syslog: true

# If enabled, apm-server periodically logs its internal metrics that have changed
# in the last period. For each metric that changed, the delta from the value at
# the beginning of the period is logged. Also, the total values for
# all non-zero internal metrics are logged on shutdown. The default is true.
#logging.metrics.enabled: true

# The period after which to log the internal metrics. The default is 30s.
#logging.metrics.period: 30s

# Logging to rotating files files. Set logging.to_files to false to disable logging to
# files.
logging.to_files: true
logging.files:
  # Configure the path where the logs are written. The default is the logs directory
  # under the home path (the binary location).
  #path: /var/log/apm-server

  # The name of the files where the logs are written to.
  #name: apm-server

  # Configure log file size limit. If limit is reached, log file will be
  # automatically rotated
  #rotateeverybytes: 10485760 # = 10MB

  # Number of rotated log files to keep. Oldest files will be deleted first.
  #keepfiles: 7

# Set to true to log messages in json format.
#logging.json: false