Unable to perform search query error

After a long time I started my old graylog machine, and I get this message. I checked server.conf looks like this

############################
# GRAYLOG CONFIGURATION FILE
############################
#
# This is the Graylog configuration file. The file has to use ISO 8859-1/Latin-1 character encoding.
# Characters that cannot be directly represented in this encoding can be written using Unicode escapes
# as defined in https://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-3.3, using the \u prefix.
# For example, \u002c.
# 
# * Entries are generally expected to be a single line of the form, one of the following:
#
# propertyName=propertyValue
# propertyName:propertyValue
#
# * White space that appears between the property name and property value is ignored,
#   so the following are equivalent:
# 
# name=Stephen
# name = Stephen
#
# * White space at the beginning of the line is also ignored.
#
# * Lines that start with the comment characters ! or # are ignored. Blank lines are also ignored.
#
# * The property value is generally terminated by the end of the line. White space following the
#   property value is not ignored, and is treated as part of the property value.
#
# * A property value can span several lines if each line is terminated by a backslash (‘\’) character.
#   For example:
#
# targetCities=\
#         Detroit,\
#         Chicago,\
#         Los Angeles
#
#   This is equivalent to targetCities=Detroit,Chicago,Los Angeles (white space at the beginning of lines is ignored).
# 
# * The characters newline, carriage return, and tab can be inserted with characters \n, \r, and \t, respectively.
# 
# * The backslash character must be escaped as a double backslash. For example:
# 
# path=c:\\docs\\doc1
#

# If you are running more than one instances of Graylog server you have to select one of these
# instances as master. The master will perform some periodical tasks that non-masters won't perform.
is_master = true

# The auto-generated node ID will be stored in this file and read after restarts. It is a good idea
# to use an absolute file path here if you are starting Graylog server from init scripts or similar.
node_id_file = /etc/graylog/server/node-id

# You MUST set a secret to secure/pepper the stored user passwords here. Use at least 64 characters.
# Generate one by using for example: pwgen -N 1 -s 96
password_secret = vEWvQ9UALJUF1sb

# The default root user is named 'admin'
#root_username = admin

# You MUST specify a hash password for the root user (which you only need to initially set up the
# system and in case you lose connectivity to your authentication backend)
# This password cannot be changed using the API or via the web interface. If you need to change it,
# modify it in this file.
# Create one by using for example: echo -n yourpassword | shasum -a 256
# and put the resulting hash value into the following line
root_password_sha2 = da45cf0

# The email address of the root user.
# Default is empty
#root_email = ""

# The time zone setting of the root user. See http://www.joda.org/joda-time/timezones.html for a list of valid time zones.
# Default is UTC
#root_timezone = UTC
root_timezone = Europe/Warsaw
# Set the bin directory here (relative or absolute)
# This directory contains binaries that are used by the Graylog server.
# Default: bin
bin_dir = /usr/share/graylog-server/bin

# Set the data directory here (relative or absolute)
# This directory is used to store Graylog server state.
# Default: data
data_dir = /var/lib/graylog-server

# Set plugin directory here (relative or absolute)
plugin_dir = /usr/share/graylog-server/plugin

###############
# HTTP settings
###############

#### HTTP bind address
#
# The network interface used by the Graylog HTTP interface.
#
# This network interface must be accessible by all Graylog nodes in the cluster and by all clients
# using the Graylog web interface.
#
# If the port is omitted, Graylog will use port 9000 by default.
#
# Default: 127.0.0.1:9000
http_bind_address = IP SERVER:9000
#http_bind_address = [2001:db8::1]:9000

#### HTTP publish URI
#
# The HTTP URI of this Graylog node which is used to communicate with the other Graylog nodes in the cluster and by all
# clients using the Graylog web interface.
#
# The URI will be published in the cluster discovery APIs, so that other Graylog nodes will be able to find and connect to this Graylog node.
#
# This configuration setting has to be used if this Graylog node is available on another network interface than $http_bind_address,
# for example if the machine has multiple network interfaces or is behind a NAT gateway.
#
# If $http_bind_address contains a wildcard IPv4 address (0.0.0.0), the first non-loopback IPv4 address of this machine will be used.
# This configuration setting *must not* contain a wildcard address!
#
# Default: http://$http_bind_address/
#http_publish_uri = http://192.168.1.1:9000/

#### External Graylog URI
#
# The public URI of Graylog which will be used by the Graylog web interface to communicate with the Graylog REST API.
#
# The external Graylog URI usually has to be specified, if Graylog is running behind a reverse proxy or load-balancer
# and it will be used to generate URLs addressing entities in the Graylog REST API (see $http_bind_address).
#
# When using Graylog Collector, this URI will be used to receive heartbeat messages and must be accessible for all collectors.
#
# This setting can be overriden on a per-request basis with the "X-Graylog-Server-URL" HTTP request header.
#
# Default: $http_publish_uri
#http_external_uri =

#### Enable CORS headers for HTTP interface
#
# This is necessary for JS-clients accessing the server directly.
# If these are disabled, modern browsers will not be able to retrieve resources from the server.
# This is enabled by default. Uncomment the next line to disable it.
#http_enable_cors = false

#### Enable GZIP support for HTTP interface
#
# This compresses API responses and therefore helps to reduce
# overall round trip times. This is enabled by default. Uncomment the next line to disable it.
#http_enable_gzip = false

# The maximum size of the HTTP request headers in bytes.
#http_max_header_size = 8192

# The size of the thread pool used exclusively for serving the HTTP interface.
#http_thread_pool_size = 16

################
# HTTPS settings
################

#### Enable HTTPS support for the HTTP interface
#
# This secures the communication with the HTTP interface with TLS to prevent request forgery and eavesdropping.
#
# Default: false
#http_enable_tls = true

# The X.509 certificate chain file in PEM format to use for securing the HTTP interface.
#http_tls_cert_file = /path/to/graylog.crt

# The PKCS#8 private key file in PEM format to use for securing the HTTP interface.
#http_tls_key_file = /path/to/graylog.key

# The password to unlock the private key used for securing the HTTP interface.
#http_tls_key_password = secret


# Comma separated list of trusted proxies that are allowed to set the client address with X-Forwarded-For
# header. May be subnets, or hosts.
#trusted_proxies = 127.0.0.1/32, 0:0:0:0:0:0:0:1/128

# List of Elasticsearch hosts Graylog should connect to.
# Need to be specified as a comma-separated list of valid URIs for the http ports of your elasticsearch nodes.
# If one or more of your elasticsearch hosts require authentication, include the credentials in each node URI that
# requires authentication.
#
# Default: http://127.0.0.1:9200
#elasticsearch_hosts = http://node1:9200,http://user:password@node2:19200

# Maximum amount of time to wait for successfull connection to Elasticsearch HTTP port.
#
# Default: 10 Seconds
#elasticsearch_connect_timeout = 10s

# Maximum amount of time to wait for reading back a response from an Elasticsearch server.
#
# Default: 60 seconds
#elasticsearch_socket_timeout = 60s

# Maximum idle time for an Elasticsearch connection. If this is exceeded, this connection will
# be tore down.
#
# Default: inf
#elasticsearch_idle_timeout = -1s

# Maximum number of total connections to Elasticsearch.
#
# Default: 20
#elasticsearch_max_total_connections = 20

# Maximum number of total connections per Elasticsearch route (normally this means per
# elasticsearch server).
#
# Default: 2
#elasticsearch_max_total_connections_per_route = 2

# Maximum number of times Graylog will retry failed requests to Elasticsearch.
#
# Default: 2
#elasticsearch_max_retries = 2

# Enable automatic Elasticsearch node discovery through Nodes Info,
# see https://www.elastic.co/guide/en/elasticsearch/reference/5.4/cluster-nodes-info.html
#
# WARNING: Automatic node discovery does not work if Elasticsearch requires authentication, e. g. with Shield.
#
# Default: false
#elasticsearch_discovery_enabled = true

# Filter for including/excluding Elasticsearch nodes in discovery according to their custom attributes,
# see https://www.elastic.co/guide/en/elasticsearch/reference/5.4/cluster.html#cluster-nodes
#
# Default: empty
#elasticsearch_discovery_filter = rack:42

# Frequency of the Elasticsearch node discovery.
#
# Default: 30s
# elasticsearch_discovery_frequency = 30s

# Enable payload compression for Elasticsearch requests.
#
# Default: false
#elasticsearch_compression_enabled = true

# Graylog will use multiple indices to store documents in. You can configured the strategy it uses to determine
# when to rotate the currently active write index.
# It supports multiple rotation strategies:
#   - "count" of messages per index, use elasticsearch_max_docs_per_index below to configure
#   - "size" per index, use elasticsearch_max_size_per_index below to configure
# valid values are "count", "size" and "time", default is "count"
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
rotation_strategy = count

# (Approximate) maximum number of documents in an Elasticsearch index before a new index
# is being created, also see no_retention and elasticsearch_max_number_of_indices.
# Configure this if you used 'rotation_strategy = count' above.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
elasticsearch_max_docs_per_index = 20000000

# (Approximate) maximum size in bytes per Elasticsearch index on disk before a new index is being created, also see
# no_retention and elasticsearch_max_number_of_indices. Default is 1GB.
# Configure this if you used 'rotation_strategy = size' above.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
#elasticsearch_max_size_per_index = 1073741824

# (Approximate) maximum time before a new Elasticsearch index is being created, also see
# no_retention and elasticsearch_max_number_of_indices. Default is 1 day.
# Configure this if you used 'rotation_strategy = time' above.
# Please note that this rotation period does not look at the time specified in the received messages, but is
# using the real clock value to decide when to rotate the index!
# Specify the time using a duration and a suffix indicating which unit you want:
#  1w  = 1 week
#  1d  = 1 day
#  12h = 12 hours
# Permitted suffixes are: d for day, h for hour, m for minute, s for second.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
#elasticsearch_max_time_per_index = 1d

# Disable checking the version of Elasticsearch for being compatible with this Graylog release.
# WARNING: Using Graylog with unsupported and untested versions of Elasticsearch may lead to data loss!
#elasticsearch_disable_version_check = true

# Disable message retention on this node, i. e. disable Elasticsearch index rotation.
#no_retention = false

# How many indices do you want to keep?
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
elasticsearch_max_number_of_indices = 20

# Decide what happens with the oldest indices when the maximum number of indices is reached.
# The following strategies are availble:
#   - delete # Deletes the index completely (Default)
#   - close # Closes the index and hides it from the system. Can be re-opened later.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
retention_strategy = delete

# How many Elasticsearch shards and replicas should be used per index? Note that this only applies to newly created indices.
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
elasticsearch_shards = 4
elasticsearch_replicas = 0

# Prefix for all Elasticsearch indices and index aliases managed by Graylog.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
elasticsearch_index_prefix = graylog

# Name of the Elasticsearch index template used by Graylog to apply the mandatory index mapping.
# Default: graylog-internal
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
#elasticsearch_template_name = graylog-internal

# Do you want to allow searches with leading wildcards? This can be extremely resource hungry and should only
# be enabled with care. See also: http://docs.graylog.org/en/2.1/pages/queries.html
allow_leading_wildcard_searches = false

# Do you want to allow searches to be highlighted? Depending on the size of your messages this can be memory hungry and
# should only be enabled after making sure your Elasticsearch cluster has enough memory.
allow_highlighting = false

# Analyzer (tokenizer) to use for message and full_message field. The "standard" filter usually is a good idea.
# All supported analyzers are: standard, simple, whitespace, stop, keyword, pattern, language, snowball, custom
# Elasticsearch documentation: https://www.elastic.co/guide/en/elasticsearch/reference/2.3/analysis.html
# Note that this setting only takes effect on newly created indices.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
elasticsearch_analyzer = standard

# Global request timeout for Elasticsearch requests (e. g. during search, index creation, or index time-range
# calculations) based on a best-effort to restrict the runtime of Elasticsearch operations.
# Default: 1m
#elasticsearch_request_timeout = 1m

# Global timeout for index optimization (force merge) requests.
# Default: 1h
#elasticsearch_index_optimization_timeout = 1h

# Maximum number of concurrently running index optimization (force merge) jobs.
# If you are using lots of different index sets, you might want to increase that number.
# Default: 20
#elasticsearch_index_optimization_jobs = 20

# Time interval for index range information cleanups. This setting defines how often stale index range information
# is being purged from the database.
# Default: 1h
#index_ranges_cleanup_interval = 1h

# Time interval for the job that runs index field type maintenance tasks like cleaning up stale entries. This doesn't
# need to run very often.
# Default: 1h
#index_field_type_periodical_interval = 1h

# Batch size for the Elasticsearch output. This is the maximum (!) number of messages the Elasticsearch output
# module will get at once and write to Elasticsearch in a batch call. If the configured batch size has not been
# reached within output_flush_interval seconds, everything that is available will be flushed at once. Remember
# that every outputbuffer processor manages its own batch and performs its own batch write calls.
# ("outputbuffer_processors" variable)
output_batch_size = 500

# Flush interval (in seconds) for the Elasticsearch output. This is the maximum amount of time between two
# batches of messages written to Elasticsearch. It is only effective at all if your minimum number of messages
# for this time period is less than output_batch_size * outputbuffer_processors.
output_flush_interval = 1

# As stream outputs are loaded only on demand, an output which is failing to initialize will be tried over and
# over again. To prevent this, the following configuration options define after how many faults an output will
# not be tried again for an also configurable amount of seconds.
output_fault_count_threshold = 5
output_fault_penalty_seconds = 30

# The number of parallel running processors.
# Raise this number if your buffers are filling up.
processbuffer_processors = 5
outputbuffer_processors = 3

# The following settings (outputbuffer_processor_*) configure the thread pools backing each output buffer processor.
# See https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ThreadPoolExecutor.html for technical details

# When the number of threads is greater than the core (see outputbuffer_processor_threads_core_pool_size),
# this is the maximum time in milliseconds that excess idle threads will wait for new tasks before terminating.
# Default: 5000
#outputbuffer_processor_keep_alive_time = 5000

# The number of threads to keep in the pool, even if they are idle, unless allowCoreThreadTimeOut is set
# Default: 3
#outputbuffer_processor_threads_core_pool_size = 3

# The maximum number of threads to allow in the pool
# Default: 30
#outputbuffer_processor_threads_max_pool_size = 30

# UDP receive buffer size for all message inputs (e. g. SyslogUDPInput).
#udp_recvbuffer_sizes = 1048576

# Wait strategy describing how buffer processors wait on a cursor sequence. (default: sleeping)
# Possible types:
#  - yielding
#     Compromise between performance and CPU usage.
#  - sleeping
#     Compromise between performance and CPU usage. Latency spikes can occur after quiet periods.
#  - blocking
#     High throughput, low latency, higher CPU usage.
#  - busy_spinning
#     Avoids syscalls which could introduce latency jitter. Best when threads can be bound to specific CPU cores.
processor_wait_strategy = blocking

# Size of internal ring buffers. Raise this if raising outputbuffer_processors does not help anymore.
# For optimum performance your LogMessage objects in the ring buffer should fit in your CPU L3 cache.
# Must be a power of 2. (512, 1024, 2048, ...)
ring_size = 65536

inputbuffer_ring_size = 65536
inputbuffer_processors = 2
inputbuffer_wait_strategy = blocking

# Enable the disk based message journal.
message_journal_enabled = true

# The directory which will be used to store the message journal. The directory must me exclusively used by Graylog and
# must not contain any other files than the ones created by Graylog itself.
#
# ATTENTION:
#   If you create a seperate partition for the journal files and use a file system creating directories like 'lost+found'
#   in the root directory, you need to create a sub directory for your journal.
#   Otherwise Graylog will log an error message that the journal is corrupt and Graylog will not start.
message_journal_dir = /var/lib/graylog-server/journal

# Journal hold messages before they could be written to Elasticsearch.
# For a maximum of 12 hours or 5 GB whichever happens first.
# During normal operation the journal will be smaller.
#message_journal_max_age = 12h
#message_journal_max_size = 5gb

#message_journal_flush_age = 1m
#message_journal_flush_interval = 1000000
#message_journal_segment_age = 1h
#message_journal_segment_size = 100mb

# Number of threads used exclusively for dispatching internal events. Default is 2.
#async_eventbus_processors = 2

# How many seconds to wait between marking node as DEAD for possible load balancers and starting the actual
# shutdown process. Set to 0 if you have no status checking load balancers in front.
lb_recognition_period_seconds = 3

# Journal usage percentage that triggers requesting throttling for this server node from load balancers. The feature is
# disabled if not set.
#lb_throttle_threshold_percentage = 95

# Every message is matched against the configured streams and it can happen that a stream contains rules which
# take an unusual amount of time to run, for example if its using regular expressions that perform excessive backtracking.
# This will impact the processing of the entire server. To keep such misbehaving stream rules from impacting other
# streams, Graylog limits the execution time for each stream.
# The default values are noted below, the timeout is in milliseconds.
# If the stream matching for one stream took longer than the timeout value, and this happened more than "max_faults" times
# that stream is disabled and a notification is shown in the web interface.
#stream_processing_timeout = 2000
#stream_processing_max_faults = 3

# Length of the interval in seconds in which the alert conditions for all streams should be checked
# and alarms are being sent.
#alert_check_interval = 60

# Since 0.21 the Graylog server supports pluggable output modules. This means a single message can be written to multiple
# outputs. The next setting defines the timeout for a single output module, including the default output module where all
# messages end up.
#
# Time in milliseconds to wait for all message outputs to finish writing a single message.
#output_module_timeout = 10000

# Time in milliseconds after which a detected stale master node is being rechecked on startup.
#stale_master_timeout = 2000

# Time in milliseconds which Graylog is waiting for all threads to stop on shutdown.
#shutdown_timeout = 30000

# MongoDB connection string
# See https://docs.mongodb.com/manual/reference/connection-string/ for details
mongodb_uri = mongodb://localhost/graylog

# Authenticate against the MongoDB server
# '+'-signs in the username or password need to be replaced by '%2B'
#mongodb_uri = mongodb://grayloguser:secret@localhost:27017/graylog

continued

# Use a replica set instead of a single host
#mongodb_uri = mongodb://grayloguser:secret@localhost:27017,localhost:27018,localhost:27019/graylog

# Increase this value according to the maximum connections your MongoDB server can handle from a single client
# if you encounter MongoDB connection problems.
mongodb_max_connections = 1000

# Number of threads allowed to be blocked by MongoDB connections multiplier. Default: 5
# If mongodb_max_connections is 100, and mongodb_threads_allowed_to_block_multiplier is 5,
# then 500 threads can block. More than that and an exception will be thrown.
# http://api.mongodb.com/java/current/com/mongodb/MongoOptions.html#threadsAllowedToBlockForConnectionMultiplier
mongodb_threads_allowed_to_block_multiplier = 5


# Email transport
#transport_email_enabled = false
#transport_email_hostname = mail.example.com
#transport_email_port = 587
#transport_email_use_auth = true
#transport_email_auth_username = you@example.com
#transport_email_auth_password = secret
#transport_email_subject_prefix = [graylog]
#transport_email_from_email = graylog@example.com

# Encryption settings
#
# ATTENTION:
#    Using SMTP with STARTTLS *and* SMTPS at the same time is *not* possible.

# Use SMTP with STARTTLS, see https://en.wikipedia.org/wiki/Opportunistic_TLS
#transport_email_use_tls = true

# Use SMTP over SSL (SMTPS), see https://en.wikipedia.org/wiki/SMTPS
# This is deprecated on most SMTP services!
#transport_email_use_ssl = true


# Specify and uncomment this if you want to include links to the stream in your stream alert mails.
# This should define the fully qualified base url to your web interface exactly the same way as it is accessed by your users.
#transport_email_web_interface_url = https://graylog.example.com

# The default connect timeout for outgoing HTTP connections.
# Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
# Default: 5s
#http_connect_timeout = 5s

# The default read timeout for outgoing HTTP connections.
# Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
# Default: 10s
#http_read_timeout = 10s

# The default write timeout for outgoing HTTP connections.
# Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
# Default: 10s
#http_write_timeout = 10s

# HTTP proxy for outgoing HTTP connections
# ATTENTION: If you configure a proxy, make sure to also configure the "http_non_proxy_hosts" option so internal
#            HTTP connections with other nodes does not go through the proxy.
# Examples:
#   - http://proxy.example.com:8123
#   - http://username:password@proxy.example.com:8123
#http_proxy_uri =

# A list of hosts that should be reached directly, bypassing the configured proxy server.
# This is a list of patterns separated by ",". The patterns may start or end with a "*" for wildcards.
# Any host matching one of these patterns will be reached through a direct connection instead of through a proxy.
# Examples:
#   - localhost,127.0.0.1
#   - 10.0.*,*.example.com
#http_non_proxy_hosts =

# Disable the optimization of Elasticsearch indices after index cycling. This may take some load from Elasticsearch
# on heavily used systems with large indices, but it will decrease search performance. The default is to optimize
# cycled indices.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
#disable_index_optimization = true

# Optimize the index down to <= index_optimization_max_num_segments. A higher number may take some load from Elasticsearch
# on heavily used systems with large indices, but it will decrease search performance. The default is 1.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
#index_optimization_max_num_segments = 1

# The threshold of the garbage collection runs. If GC runs take longer than this threshold, a system notification
# will be generated to warn the administrator about possible problems with the system. Default is 1 second.
#gc_warning_threshold = 1s

# Connection timeout for a configured LDAP server (e. g. ActiveDirectory) in milliseconds.
#ldap_connection_timeout = 2000

# Disable the use of SIGAR for collecting system stats
#disable_sigar = false

# The default cache time for dashboard widgets. (Default: 10 seconds, minimum: 1 second)
#dashboard_widget_default_cache_time = 10s

# For some cluster-related REST requests, the node must query all other nodes in the cluster. This is the maximum number
# of threads available for this. Increase it, if '/cluster/*' requests take long to complete.
# Should be http_thread_pool_size * average_cluster_size if you have a high number of concurrent users.
proxied_requests_thread_pool_size = 32

I would check your elasticsearch

I have copied the settings as I put the machine and they looked like they changed themselves?
it worries me because i have very important logs there.
How to recover them?

############################
# GRAYLOG CONFIGURATION FILE
############################
#
# This is the Graylog configuration file. The file has to use ISO 8859-1/Latin-1 character encoding.
# Characters that cannot be directly represented in this encoding can be written using Unicode escapes
# as defined in https://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-3.3, using the \u prefix.
# For example, \u002c.
# 
# * Entries are generally expected to be a single line of the form, one of the following:
#
# propertyName=propertyValue
# propertyName:propertyValue
#
# * White space that appears between the property name and property value is ignored,
#   so the following are equivalent:
# 
# name=Stephen
# name = Stephen
#
# * White space at the beginning of the line is also ignored.
#
# * Lines that start with the comment characters ! or # are ignored. Blank lines are also ignored.
#
# * The property value is generally terminated by the end of the line. White space following the
#   property value is not ignored, and is treated as part of the property value.
#
# * A property value can span several lines if each line is terminated by a backslash (‘\’) character.
#   For example:
#
# targetCities=\
#         Detroit,\
#         Chicago,\
#         Los Angeles
#
#   This is equivalent to targetCities=Detroit,Chicago,Los Angeles (white space at the beginning of lines is ignored).
# 
# * The characters newline, carriage return, and tab can be inserted with characters \n, \r, and \t, respectively.
# 
# * The backslash character must be escaped as a double backslash. For example:
# 
# path=c:\\docs\\doc1
#

# If you are running more than one instances of Graylog server you have to select one of these
# instances as master. The master will perform some periodical tasks that non-masters won't perform.
is_master = true

# The auto-generated node ID will be stored in this file and read after restarts. It is a good idea
# to use an absolute file path here if you are starting Graylog server from init scripts or similar.
node_id_file = /etc/graylog/server/node-id

# You MUST set a secret to secure/pepper the stored user passwords here. Use at least 64 characters.
# Generate one by using for example: pwgen -N 1 -s 96
password_secret = 7Sd1v7eTg37FQe5hP8R2IHPxUOKhJT7Ej46y9PfkNbDUR1octnR0jjdYmQB9FC3DZjVC8PkdP6bevMq5dgxmP3f1EeYHNlI6


# The default root user is named 'admin'
#root_username = admin

# You MUST specify a hash password for the root user (which you only need to initially set up the
# system and in case you lose connectivity to your authentication backend)
# This password cannot be changed using the API or via the web interface. If you need to change it,
# modify it in this file.
# Create one by using for example: echo -n yourpassword | shasum -a 256
# and put the resulting hash value into the following line
root_password_sha2 = da45cf056
  
# The email address of the root user.
# Default is empty
#root_email = ""

# The time zone setting of the root user. See http://www.joda.org/joda-time/timezones.html for a list of valid time zones.
# Default is UTC
# root_timezone = UTC
root_timezone = Europe/Warsaw
# Set plugin directory here (relative or absolute)
plugin_dir = /usr/share/graylog-server/plugin

# REST API listen URI. Must be reachable by other Graylog server nodes if you run a cluster.
# When using Graylog Collectors, this URI will be used to receive heartbeat messages and must be accessible for all collectors.
rest_listen_uri = http://IPSERVER:9000/api/

# REST API transport address. Defaults to the value of rest_listen_uri. Exception: If rest_listen_uri
# is set to a wildcard IP address (0.0.0.0) the first non-loopback IPv4 system address is used.
# If set, this will be promoted in the cluster discovery APIs, so other nodes may try to connect on
# this address and it is used to generate URLs addressing entities in the REST API. (see rest_listen_uri)
# You will need to define this, if your Graylog server is running behind a HTTP proxy that is rewriting
# the scheme, host name or URI.
# This must not contain a wildcard address (0.0.0.0).
#rest_transport_uri = http://192.168.1.1:9000/api/

# Enable CORS headers for REST API. This is necessary for JS-clients accessing the server directly.
# If these are disabled, modern browsers will not be able to retrieve resources from the server.
# This is enabled by default. Uncomment the next line to disable it.
#rest_enable_cors = false

# Enable GZIP support for REST API. This compresses API responses and therefore helps to reduce
# overall round trip times. This is enabled by default. Uncomment the next line to disable it.
#rest_enable_gzip = false

# Enable HTTPS support for the REST API. This secures the communication with the REST API with
# TLS to prevent request forgery and eavesdropping. This is disabled by default. Uncomment the
# next line to enable it.
#rest_enable_tls = true

# The X.509 certificate chain file in PEM format to use for securing the REST API.
#rest_tls_cert_file = /path/to/graylog.crt

# The PKCS#8 private key file in PEM format to use for securing the REST API.
#rest_tls_key_file = /path/to/graylog.key

# The password to unlock the private key used for securing the REST API.
#rest_tls_key_password = secret

# The maximum size of the HTTP request headers in bytes.
#rest_max_header_size = 8192

# The maximal length of the initial HTTP/1.1 line in bytes.
#rest_max_initial_line_length = 4096

# The size of the thread pool used exclusively for serving the REST API.
#rest_thread_pool_size = 16

# Comma separated list of trusted proxies that are allowed to set the client address with X-Forwarded-For
# header. May be subnets, or hosts.
#trusted_proxies = 127.0.0.1/32, 0:0:0:0:0:0:0:1/128

# Enable the embedded Graylog web interface.
# Default: true
#web_enable = false

# Web interface listen URI.
# Configuring a path for the URI here effectively prefixes all URIs in the web interface. This is a replacement
# for the application.context configuration parameter in pre-2.0 versions of the Graylog web interface.
web_listen_uri = http://IPSERVER:9000/

# Web interface endpoint URI. This setting can be overriden on a per-request basis with the X-Graylog-Server-URL header.
# Default: $rest_transport_uri
#web_endpoint_uri =

# Enable CORS headers for the web interface. This is necessary for JS-clients accessing the server directly.
# If these are disabled, modern browsers will not be able to retrieve resources from the server.
#web_enable_cors = false

# Enable/disable GZIP support for the web interface. This compresses HTTP responses and therefore helps to reduce
# overall round trip times. This is enabled by default. Uncomment the next line to disable it.
#web_enable_gzip = false

# Enable HTTPS support for the web interface. This secures the communication of the web browser with the web interface
# using TLS to prevent request forgery and eavesdropping.
# This is disabled by default. Uncomment the next line to enable it and see the other related configuration settings.
#web_enable_tls = true

# The X.509 certificate chain file in PEM format to use for securing the web interface.
#web_tls_cert_file = /path/to/graylog-web.crt

# The PKCS#8 private key file in PEM format to use for securing the web interface.
#web_tls_key_file = /path/to/graylog-web.key

# The password to unlock the private key used for securing the web interface.
#web_tls_key_password = secret

# The maximum size of the HTTP request headers in bytes.
#web_max_header_size = 8192

# The maximal length of the initial HTTP/1.1 line in bytes.
#web_max_initial_line_length = 4096

# The size of the thread pool used exclusively for serving the web interface.
#web_thread_pool_size = 16

# Configuration file for the embedded Elasticsearch instance in Graylog.
# Pay attention to the working directory of the server, maybe use an absolute path here.
# Default: empty
#elasticsearch_config_file = /etc/graylog/server/elasticsearch.yml

# Graylog will use multiple indices to store documents in. You can configured the strategy it uses to determine
# when to rotate the currently active write index.
# It supports multiple rotation strategies:
#   - "count" of messages per index, use elasticsearch_max_docs_per_index below to configure
#   - "size" per index, use elasticsearch_max_size_per_index below to configure
# valid values are "count", "size" and "time", default is "count"
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
rotation_strategy = count

# (Approximate) maximum number of documents in an Elasticsearch index before a new index
# is being created, also see no_retention and elasticsearch_max_number_of_indices.
# Configure this if you used 'rotation_strategy = count' above.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
elasticsearch_max_docs_per_index = 20000000

# (Approximate) maximum size in bytes per Elasticsearch index on disk before a new index is being created, also see
# no_retention and elasticsearch_max_number_of_indices. Default is 1GB.
# Configure this if you used 'rotation_strategy = size' above.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#elasticsearch_max_size_per_index = 1073741824

# (Approximate) maximum time before a new Elasticsearch index is being created, also see
# no_retention and elasticsearch_max_number_of_indices. Default is 1 day.
# Configure this if you used 'rotation_strategy = time' above.
# Please note that this rotation period does not look at the time specified in the received messages, but is
# using the real clock value to decide when to rotate the index!
# Specify the time using a duration and a suffix indicating which unit you want:
#  1w  = 1 week
#  1d  = 1 day
#  12h = 12 hours
# Permitted suffixes are: d for day, h for hour, m for minute, s for second.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#elasticsearch_max_time_per_index = 1d

# Disable checking the version of Elasticsearch for being compatible with this Graylog release.
# WARNING: Using Graylog with unsupported and untested versions of Elasticsearch may lead to data loss!
#elasticsearch_disable_version_check = true

# Disable message retention on this node, i. e. disable Elasticsearch index rotation.
#no_retention = false

# How many indices do you want to keep?
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
elasticsearch_max_number_of_indices = 20

# Decide what happens with the oldest indices when the maximum number of indices is reached.
# The following strategies are availble:
#   - delete # Deletes the index completely (Default)
#   - close # Closes the index and hides it from the system. Can be re-opened later.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
retention_strategy = delete

# How many Elasticsearch shards and replicas should be used per index? Note that this only applies to newly created indices.
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
elasticsearch_shards = 4
elasticsearch_replicas = 0

# Prefix for all Elasticsearch indices and index aliases managed by Graylog.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
elasticsearch_index_prefix = graylog

# Name of the Elasticsearch index template used by Graylog to apply the mandatory index mapping.
# Default: graylog-internal
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#elasticsearch_template_name = graylog-internal

# Do you want to allow searches with leading wildcards? This can be extremely resource hungry and should only
# be enabled with care. See also: http://docs.graylog.org/en/2.1/pages/queries.html
allow_leading_wildcard_searches = false

# Do you want to allow searches to be highlighted? Depending on the size of your messages this can be memory hungry and
# should only be enabled after making sure your Elasticsearch cluster has enough memory.
allow_highlighting = false

# settings to be passed to elasticsearch's client (overriding those in the provided elasticsearch_config_file)
# all these
# this must be the same as for your Elasticsearch cluster
#elasticsearch_cluster_name = graylog

# The prefix being used to generate the Elasticsearch node name which makes it easier to identify the specific Graylog
# server running the embedded Elasticsearch instance. The node name will be constructed by concatenating this prefix
# and the Graylog node ID (see node_id_file), for example "graylog-17052010-1234-5678-abcd-1337cafebabe".
# Default: graylog-
#elasticsearch_node_name_prefix = graylog-

# A comma-separated list of Elasticsearch nodes which Graylog is using to connect to the Elasticsearch cluster,
# see https://www.elastic.co/guide/en/elasticsearch/reference/2.3/modules-discovery-zen.html for details.
# Default: 127.0.0.1
#elasticsearch_discovery_zen_ping_unicast_hosts = 127.0.0.1:9300

# Use multiple Elasticsearch nodes as seed
#elasticsearch_discovery_zen_ping_unicast_hosts = 198.51.100.23:9300, 198.51.100.42:9300

# we don't want the Graylog server to store any data, or be master node
#elasticsearch_node_master = false
#elasticsearch_node_data = false

# use a different port if you run multiple Elasticsearch nodes on one machine
#elasticsearch_transport_tcp_port = 9350

# we don't need to run the embedded HTTP server here
#elasticsearch_http_enabled = false

# Change the following setting if you are running into problems with timeouts during Elasticsearch cluster discovery.
# The setting is specified in milliseconds, the default is 5000ms (5 seconds).
#elasticsearch_cluster_discovery_timeout = 5000

# the following settings allow to change the bind addresses for the Elasticsearch client in Graylog
# these settings are empty by default, letting Elasticsearch choose automatically,
# override them here or in the 'elasticsearch_config_file' if you need to bind to a special address
# refer to https://www.elastic.co/guide/en/elasticsearch/reference/2.3/modules-network.html
# for special values here
#elasticsearch_network_host =
#elasticsearch_network_bind_host =
#elasticsearch_network_publish_host =

# The total amount of time discovery will look for other Elasticsearch nodes in the cluster
# before giving up and declaring the current node master.
#elasticsearch_discovery_initial_state_timeout = 3s

# Analyzer (tokenizer) to use for message and full_message field. The "standard" filter usually is a good idea.
# All supported analyzers are: standard, simple, whitespace, stop, keyword, pattern, language, snowball, custom
# Elasticsearch documentation: https://www.elastic.co/guide/en/elasticsearch/reference/2.3/analysis.html
# Note that this setting only takes effect on newly created indices.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
elasticsearch_analyzer = standard

# Global request timeout for Elasticsearch requests (e. g. during search, index creation, or index time-range
# calculations) based on a best-effort to restrict the runtime of Elasticsearch operations.
# Default: 1m
#elasticsearch_request_timeout = 1m

# Global timeout for index optimization (force merge) requests.
# Default: 1h
#elasticsearch_index_optimization_timeout = 1h

# Maximum number of concurrently running index optimization (force merge) jobs.
# If you are using lots of different index sets, you might want to increase that number.
# Default: 20
#elasticsearch_index_optimization_jobs = 20

# Time interval for index range information cleanups. This setting defines how often stale index range information
# is being purged from the database.
# Default: 1h
#index_ranges_cleanup_interval = 1h

# Batch size for the Elasticsearch output. This is the maximum (!) number of messages the Elasticsearch output
# module will get at once and write to Elasticsearch in a batch call. If the configured batch size has not been
# reached within output_flush_interval seconds, everything that is available will be flushed at once. Remember
# that every outputbuffer processor manages its own batch and performs its own batch write calls.
# ("outputbuffer_processors" variable)
output_batch_size = 500

# Flush interval (in seconds) for the Elasticsearch output. This is the maximum amount of time between two
# batches of messages written to Elasticsearch. It is only effective at all if your minimum number of messages
# for this time period is less than output_batch_size * outputbuffer_processors.
output_flush_interval = 1

# As stream outputs are loaded only on demand, an output which is failing to initialize will be tried over and
# over again. To prevent this, the following configuration options define after how many faults an output will
# not be tried again for an also configurable amount of seconds.
output_fault_count_threshold = 5
output_fault_penalty_seconds = 30

# The number of parallel running processors.
# Raise this number if your buffers are filling up.
processbuffer_processors = 5
outputbuffer_processors = 3

#outputbuffer_processor_keep_alive_time = 5000
#outputbuffer_processor_threads_core_pool_size = 3
#outputbuffer_processor_threads_max_pool_size = 30
# UDP receive buffer size for all message inputs (e. g. SyslogUDPInput).
#udp_recvbuffer_sizes = 1048576

# Wait strategy describing how buffer processors wait on a cursor sequence. (default: sleeping)
# Possible types:
#  - yielding
#     Compromise between performance and CPU usage.
#  - sleeping
#     Compromise between performance and CPU usage. Latency spikes can occur after quiet periods.
#  - blocking
#     High throughput, low latency, higher CPU usage.
#  - busy_spinning
#     Avoids syscalls which could introduce latency jitter. Best when threads can be bound to specific CPU cores.
processor_wait_strategy = blocking

# Size of internal ring buffers. Raise this if raising outputbuffer_processors does not help anymore.
# For optimum performance your LogMessage objects in the ring buffer should fit in your CPU L3 cache.
# Must be a power of 2. (512, 1024, 2048, ...)
ring_size = 65536

inputbuffer_ring_size = 65536
inputbuffer_processors = 2
inputbuffer_wait_strategy = blocking

# Enable the disk based message journal.
message_journal_enabled = true

# The directory which will be used to store the message journal. The directory must me exclusively used by Graylog and
# must not contain any other files than the ones created by Graylog itself.
#
# ATTENTION:
#   If you create a seperate partition for the journal files and use a file system creating directories like 'lost+found'
#   in the root directory, you need to create a sub directory for your journal.
#   Otherwise Graylog will log an error message that the journal is corrupt and Graylog will not start.
message_journal_dir = /var/lib/graylog-server/journal

# Journal hold messages before they could be written to Elasticsearch.
# For a maximum of 12 hours or 5 GB whichever happens first.
# During normal operation the journal will be smaller.
#message_journal_max_age = 12h
#message_journal_max_size = 5gb

#message_journal_flush_age = 1m
#message_journal_flush_interval = 1000000
#message_journal_segment_age = 1h
#message_journal_segment_size = 100mb

# Number of threads used exclusively for dispatching internal events. Default is 2.
#async_eventbus_processors = 2

# How many seconds to wait between marking node as DEAD for possible load balancers and starting the actual
# shutdown process. Set to 0 if you have no status checking load balancers in front.
lb_recognition_period_seconds = 3

# Journal usage percentage that triggers requesting throttling for this server node from load balancers. The feature is
# disabled if not set.
#lb_throttle_threshold_percentage = 95

# Every message is matched against the configured streams and it can happen that a stream contains rules which
# take an unusual amount of time to run, for example if its using regular expressions that perform excessive backtracking.
# This will impact the processing of the entire server. To keep such misbehaving stream rules from impacting other
# streams, Graylog limits the execution time for each stream.
# The default values are noted below, the timeout is in milliseconds.
# If the stream matching for one stream took longer than the timeout value, and this happened more than "max_faults" times
# that stream is disabled and a notification is shown in the web interface.
#stream_processing_timeout = 2000
#stream_processing_max_faults = 3

# Length of the interval in seconds in which the alert conditions for all streams should be checked
# and alarms are being sent.
#alert_check_interval = 60

# Since 0.21 the Graylog server supports pluggable output modules. This means a single message can be written to multiple
# outputs. The next setting defines the timeout for a single output module, including the default output module where all
# messages end up.
#
# Time in milliseconds to wait for all message outputs to finish writing a single message.
#output_module_timeout = 10000

# Time in milliseconds after which a detected stale master node is being rechecked on startup.
#stale_master_timeout = 2000

# Time in milliseconds which Graylog is waiting for all threads to stop on shutdown.
#shutdown_timeout = 30000

# MongoDB connection string
# See https://docs.mongodb.com/manual/reference/connection-string/ for details
mongodb_uri = mongodb://localhost/graylog

# Authenticate against the MongoDB server
#mongodb_uri = mongodb://grayloguser:secret@localhost:27017/graylog

# Use a replica set instead of a single host
#mongodb_uri = mongodb://grayloguser:secret@localhost:27017,localhost:27018,localhost:27019/graylog

# Increase this value according to the maximum connections your MongoDB server can handle from a single client
# if you encounter MongoDB connection problems.
mongodb_max_connections = 1000

# Number of threads allowed to be blocked by MongoDB connections multiplier. Default: 5
# If mongodb_max_connections is 100, and mongodb_threads_allowed_to_block_multiplier is 5,
# then 500 threads can block. More than that and an exception will be thrown.
# http://api.mongodb.com/java/current/com/mongodb/MongoOptions.html#threadsAllowedToBlockForConnectionMultiplier
mongodb_threads_allowed_to_block_multiplier = 5

# Drools Rule File (Use to rewrite incoming log messages)
# See: http://docs.graylog.org/en/2.1/pages/drools.html
#rules_file = /etc/graylog/server/rules.drl

# Email transport
#transport_email_enabled = false
#transport_email_hostname = mail.example.com
#transport_email_port = 587
#transport_email_use_auth = true
#transport_email_use_tls = true
#transport_email_use_ssl = true
#transport_email_auth_username = you@example.com
#transport_email_auth_password = secret
#transport_email_subject_prefix = [graylog]
#transport_email_from_email = graylog@example.com

# Specify and uncomment this if you want to include links to the stream in your stream alert mails.
# This should define the fully qualified base url to your web interface exactly the same way as it is accessed by your users.
#transport_email_web_interface_url = https://graylog.example.com

# The default connect timeout for outgoing HTTP connections.
# Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
# Default: 5s
#http_connect_timeout = 5s

# The default read timeout for outgoing HTTP connections.
# Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
# Default: 10s
#http_read_timeout = 10s

# The default write timeout for outgoing HTTP connections.
# Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
# Default: 10s
#http_write_timeout = 10s

# HTTP proxy for outgoing HTTP connections
#http_proxy_uri =

# Disable the optimization of Elasticsearch indices after index cycling. This may take some load from Elasticsearch
# on heavily used systems with large indices, but it will decrease search performance. The default is to optimize
# cycled indices.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#disable_index_optimization = true

# Optimize the index down to <= index_optimization_max_num_segments. A higher number may take some load from Elasticsearch
# on heavily used systems with large indices, but it will decrease search performance. The default is 1.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#index_optimization_max_num_segments = 1

# The threshold of the garbage collection runs. If GC runs take longer than this threshold, a system notification
# will be generated to warn the administrator about possible problems with the system. Default is 1 second.
#gc_warning_threshold = 1s

# Connection timeout for a configured LDAP server (e. g. ActiveDirectory) in milliseconds.
#ldap_connection_timeout = 2000

# Disable the use of SIGAR for collecting system stats
#disable_sigar = false

# The default cache time for dashboard widgets. (Default: 10 seconds, minimum: 1 second)
#dashboard_widget_default_cache_time = 10s

# Automatically load content packs in "content_packs_dir" on the first start of Graylog.
#content_packs_loader_enabled = true

# The directory which contains content packs which should be loaded on the first start of Graylog.
content_packs_dir = /usr/share/graylog-server/contentpacks

# A comma-separated list of content packs (files in "content_packs_dir") which should be applied on
# the first start of Graylog.
# Default: empty
content_packs_auto_load = grok-patterns.json

# For some cluster-related REST requests, the node must query all other nodes in the cluster. This is the maximum number
# of threads available for this. Increase it, if '/cluster/*' requests take long to complete.
# Should be rest_thread_pool_size * average_cluster_size if you have a high number of concurrent users.
proxied_requests_thread_pool_size = 32

Config elasticsearch

#
path.data: /var/lib/elasticsearch
#
# Path to log files:
#
path.logs: /var/log/elasticsearch
#
# ----------------------------------- Memory -----------------------------------
#
# Lock the memory on startup:
#
#bootstrap.memory_lock: true
#
# Make sure that the heap size is set to about half the memory available
# on the system and that the owner of the process is allowed to use this
# limit.
#
# Elasticsearch performs poorly when the system is swapping the memory.
#
# ---------------------------------- Network -----------------------------------
#
# Set the bind address to a specific IP (IPv4 or IPv6):
#
#network.host: 192.168.0.1
#
# Set a custom port for HTTP:
#
#http.port: 9200
#
# For more information, consult the network module documentation.
#
# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when new node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
#
#discovery.zen.ping.unicast.hosts: ["host1", "host2"]
#
# Prevent the "split brain" by configuring the majority of nodes (total number of master-eligible nodes / 2 + 1):
#
#discovery.zen.minimum_master_nodes:
#
# For more information, consult the zen discovery module documentation.
#
# ---------------------------------- Gateway -----------------------------------
#
# Block initial recovery after a full cluster restart until N nodes are started:
#
#gateway.recover_after_nodes: 3
#
# For more information, consult the gateway module documentation.
#
# ---------------------------------- Various -----------------------------------
#
# Require explicit names when deleting indices:
#
#action.destructive_requires_name: true
action.auto_create_index: false
script. inline: false
sciipt. indexed: false
script.file: false 

LOG
status = error

# log action execution errors for easier debugging
logger.action.name = org.elasticsearch.action
logger.action.level = debug

appender.console.type = Console
appender.console.name = console
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = [%d{ISO8601}][%-5p][%-25c{1.}] [%node_name]%marker %m%n

appender.rolling.type = RollingFile
appender.rolling.name = rolling
appender.rolling.fileName = ${sys:es.logs.base_path}${sys:file.separator}${sys:es.logs.cluster_name}.log
appender.rolling.layout.type = PatternLayout
appender.rolling.layout.pattern = [%d{ISO8601}][%-5p][%-25c{1.}] [%node_name]%marker %.-10000m%n
appender.rolling.filePattern = ${sys:es.logs.base_path}${sys:file.separator}${sys:es.logs.cluster_name}-%d{yyyy-MM-dd}-%i.log.gz
appender.rolling.policies.type = Policies
appender.rolling.policies.time.type = TimeBasedTriggeringPolicy
appender.rolling.policies.time.interval = 1
appender.rolling.policies.time.modulate = true
appender.rolling.policies.size.type = SizeBasedTriggeringPolicy
appender.rolling.policies.size.size = 128MB
appender.rolling.strategy.type = DefaultRolloverStrategy
appender.rolling.strategy.fileIndex = nomax
appender.rolling.strategy.action.type = Delete
appender.rolling.strategy.action.basepath = ${sys:es.logs.base_path}
appender.rolling.strategy.action.condition.type = IfFileName
appender.rolling.strategy.action.condition.glob = ${sys:es.logs.cluster_name}-*
appender.rolling.strategy.action.condition.nested_condition.type = IfAccumulatedFileSize
appender.rolling.strategy.action.condition.nested_condition.exceeds = 2GB

rootLogger.level = info
rootLogger.appenderRef.console.ref = console
rootLogger.appenderRef.rolling.ref = rolling

appender.deprecation_rolling.type = RollingFile
appender.deprecation_rolling.name = deprecation_rolling
appender.deprecation_rolling.fileName = ${sys:es.logs.base_path}${sys:file.separator}${sys:es.logs.cluster_name}_deprecation.log
appender.deprecation_rolling.layout.type = PatternLayout
appender.deprecation_rolling.layout.pattern = [%d{ISO8601}][%-5p][%-25c{1.}] [%node_name]%marker %.-10000m%n
appender.deprecation_rolling.filePattern = ${sys:es.logs.base_path}${sys:file.separator}${sys:es.logs.cluster_name}_deprecation-%i.log.gz
appender.deprecation_rolling.policies.type = Policies
appender.deprecation_rolling.policies.size.type = SizeBasedTriggeringPolicy
appender.deprecation_rolling.policies.size.size = 1GB
appender.deprecation_rolling.strategy.type = DefaultRolloverStrategy
appender.deprecation_rolling.strategy.max = 4

logger.deprecation.name = org.elasticsearch.deprecation
logger.deprecation.level = warn
logger.deprecation.appenderRef.deprecation_rolling.ref = deprecation_rolling
logger.deprecation.additivity = false

appender.index_search_slowlog_rolling.type = RollingFile
appender.index_search_slowlog_rolling.name = index_search_slowlog_rolling
appender.index_search_slowlog_rolling.fileName = ${sys:es.logs.base_path}${sys:file.separator}${sys:es.logs.cluster_name}_index_search_slowlog.log
appender.index_search_slowlog_rolling.layout.type = PatternLayout
appender.index_search_slowlog_rolling.layout.pattern = [%d{ISO8601}][%-5p][%-25c] [%node_name]%marker %.-10000m%n
appender.index_search_slowlog_rolling.filePattern = ${sys:es.logs.base_path}${sys:file.separator}${sys:es.logs.cluster_name}_index_search_slowlog-%d{yyyy-MM-dd}.log
appender.index_search_slowlog_rolling.policies.type = Policies
appender.index_search_slowlog_rolling.policies.time.type = TimeBasedTriggeringPolicy
appender.index_search_slowlog_rolling.policies.time.interval = 1
appender.index_search_slowlog_rolling.policies.time.modulate = true

logger.index_search_slowlog_rolling.name = index.search.slowlog
logger.index_search_slowlog_rolling.level = trace
logger.index_search_slowlog_rolling.appenderRef.index_search_slowlog_rolling.ref = index_search_slowlog_rolling
logger.index_search_slowlog_rolling.additivity = false

appender.index_indexing_slowlog_rolling.type = RollingFile
appender.index_indexing_slowlog_rolling.name = index_indexing_slowlog_rolling
appender.index_indexing_slowlog_rolling.fileName = ${sys:es.logs.base_path}${sys:file.separator}${sys:es.logs.cluster_name}_index_indexing_slowlog.log
appender.index_indexing_slowlog_rolling.layout.type = PatternLayout
appender.index_indexing_slowlog_rolling.layout.pattern = [%d{ISO8601}][%-5p][%-25c] [%node_name]%marker %.-10000m%n
appender.index_indexing_slowlog_rolling.filePattern = ${sys:es.logs.base_path}${sys:file.separator}${sys:es.logs.cluster_name}_index_indexing_slowlog-%d{yyyy-MM-dd}.log
appender.index_indexing_slowlog_rolling.policies.type = Policies
appender.index_indexing_slowlog_rolling.policies.time.type = TimeBasedTriggeringPolicy
appender.index_indexing_slowlog_rolling.policies.time.interval = 1
appender.index_indexing_slowlog_rolling.policies.time.modulate = true

logger.index_indexing_slowlog.name = index.indexing.slowlog.index
logger.index_indexing_slowlog.level = trace
logger.index_indexing_slowlog.appenderRef.index_indexing_slowlog_rolling.ref = index_indexing_slowlog_rolling
logger.index_indexing_slowlog.additivity = false

first, you can copy easy the complete configuration file into a single posting …

But by check the status I mean - does Elasticsearch run, what is the cluster status?

● elasticsearch.service - Elasticsearch
Loaded: loaded (/usr/lib/systemd/system/elasticsearch.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Wed 2019-10-09 14:50:04 CEST; 2 days ago
Docs: http://www.elastic.co
Main PID: 5769 (code=exited, status=1/FAILURE)

paź 09 14:50:03 logi2 systemd[1]: Started Elasticsearch.
paź 09 14:50:03 logi2 elasticsearch[5769]: warning: Falling back to java on path. This behavior is deprecated. Specify JAVA_HOME
paź 09 14:50:04 logi2 elasticsearch[5769]: OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(0x0000000554cc0000, 10388504576, 0) failed; error='Cannot allocate memory' (errno=1
paź 09 14:50:04 logi2 elasticsearch[5769]: #
paź 09 14:50:04 logi2 elasticsearch[5769]: # There is insufficient memory for the Java Runtime Environment to continue.
paź 09 14:50:04 logi2 elasticsearch[5769]: # Native memory allocation (mmap) failed to map 10388504576 bytes for committing reserved memory.
paź 09 14:50:04 logi2 elasticsearch[5769]: # An error report file with more information is saved as:
paź 09 14:50:04 logi2 elasticsearch[5769]: # /var/log/elasticsearch/hs_err_pid5769.log
paź 09 14:50:04 logi2 systemd[1]: elasticsearch.service: Main process exited, code=exited, status=1/FAILURE
paź 09 14:50:04 logi2 systemd[1]: elasticsearch.service: Failed with result 'exit-code'.
~
~
~
~
~
~
~
lines 1-16/16 (END)

it looks like your elasticsearch is not running.

I repaired Java settings, moments went by. Now this message :frowning: what to do

lines 1-11/11 (END)

● elasticsearch.service - Elasticsearch
Loaded: loaded (/usr/lib/systemd/system/elasticsearch.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Mon 2019-10-14 15:36:35 CEST; 4h 55min ago
Docs: http://www.elastic.co
Process: 4019 ExecStart=/usr/share/elasticsearch/bin/elasticsearch -p ${PID_DIR}/elasticsearch.pid --quiet (code=exited,
Main PID: 4019 (code=exited, status=1/FAILURE)

paź 14 15:36:18 speedcon-logi2 systemd[1]: Started Elasticsearch.
paź 14 15:36:18 speedcon-logi2 elasticsearch[4019]: warning: Falling back to java on path. This behavior is deprecated. Sp
paź 14 15:36:35 speedcon-logi2 systemd[1]: elasticsearch.service: Main process exited, code=exited, status=1/FAILURE
paź 14 15:36:35 speedcon-logi2 systemd[1]: elasticsearch.service: Failed with result 'exit-code'.

Log elastic

OpenJDK 64-Bit Server VM (25.212-b03) for linux-amd64 JRE (1.8.0_212-8u212-b03-0ubuntu1.18.04.1-b03), built on Apr 26 2019 01:04:36 by "buildd" with gcc 7.3.0
Memory: 4k page, physical 22618476k(19927240k free), swap 2097148k(2097148k free)
CommandLine flags: -XX:+AlwaysPreTouch -XX:CMSInitiatingOccupancyFraction=75 -XX:ErrorFile=/var/log/elasticsearch/hs_err_pid%p.log -XX:GCLogFileSize=67108864 -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/var/lib/elasticsearch -XX:InitialHeapSize=10737418240 -XX:MaxHeapSize=10737418240 -XX:MaxNewSize=348966912 -XX:MaxTenuringThreshold=6 -XX:NewSize=348966912 -XX:NumberOfGCLogFiles=32 -XX:OldPLABSize=16 -XX:OldSize=697933824 -XX:-OmitStackTraceInFastThrow -XX:+PrintGC -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCDateStamps -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintTenuringDistribution -XX:ThreadStackSize=1024 -XX:+UseCMSInitiatingOccupancyOnly -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseConcMarkSweepGC -XX:+UseGCLogFileRotation -XX:+UseParNewGC 
2019-07-18T11:37:39.993+0200: 6,473: Total time for which application threads were stopped: 0,0001127 seconds, Stopping threads took: 0,0000406 seconds
2019-07-18T11:37:40.060+0200: 6,540: Total time for which application threads were stopped: 0,0001287 seconds, Stopping threads took: 0,0000378 seconds
2019-07-18T11:37:40.110+0200: 6,590: Total time for which application threads were stopped: 0,0001125 seconds, Stopping threads took: 0,0000203 seconds
2019-07-18T11:37:40.235+0200: 6,715: Total time for which application threads were stopped: 0,0002208 seconds, Stopping threads took: 0,0000879 seconds
2019-07-18T11:37:40.658+0200: 7,137: Total time for which application threads were stopped: 0,0002003 seconds, Stopping threads took: 0,0000397 seconds
2019-07-18T11:37:41.595+0200: 8,075: Total time for which application threads were stopped: 0,0001974 seconds, Stopping threads took: 0,0000663 seconds
2019-07-18T11:37:41.646+0200: 8,126: Total time for which application threads were stopped: 0,0002620 seconds, Stopping threads took: 0,0000626 seconds
2019-07-18T11:37:41.936+0200: 8,415: Total time for which application threads were stopped: 0,0003273 seconds, Stopping threads took: 0,0000547 seconds
2019-07-18T11:37:41.950+0200: 8,429: Total time for which application threads were stopped: 0,0002888 seconds, Stopping threads took: 0,0000723 seconds
2019-07-18T11:37:41.966+0200: 8,446: Total time for which application threads were stopped: 0,0036728 seconds, Stopping threads took: 0,0034071 seconds
2019-07-18T11:37:42.132+0200: 8,612: Total time for which application threads were stopped: 0,0002991 seconds, Stopping threads took: 0,0000360 seconds
2019-07-18T11:37:42.245+0200: 8,724: Total time for which application threads were stopped: 0,0003184 seconds, Stopping threads took: 0,0000707 seconds
2019-07-18T11:37:42.263+0200: 8,743: Total time for which application threads were stopped: 0,0002591 seconds, Stopping threads took: 0,0000436 seconds
2019-07-18T11:37:43.146+0200: 9,626: [GC (Allocation Failure) 2019-07-18T11:37:43.146+0200: 9,626: [ParNew

How much ram does the system have, and how much are you allocating to Elasticsearch?

Stands on a 10GB virtual machine system and the same for elastic

So the VM has 10GB total configured, and you are allocating all 10GB to Elasticsearch? I believe the general rule of thumb is to allocate no more than 50% of total system memory.

At this point I changed to 5GB for elastic (whole machine 10GB) and unfortunately it is still the same :frowning:

What is the output of your Elasticsearch log after dropping allocation to 5GB and restarting the service?