ElasticSearch 配置文件解析

Elasticsearch的config文件夾里面第一個是es的基本配置文件

[root@shnh-bak001 config]# cat elasticsearch.yml 
##################### Elasticsearch Configuration Example #####################

# This file contains an overview of various configuration settings,
# targeted at operations staff. Application developers should
# consult the guide at <http://elasticsearch.org/guide>.
#
# The installation procedure is covered at
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/setup.html>.
#
# Elasticsearch comes with reasonable defaults for most settings,
# so you can try it out without bothering with configuration.
#
# Most of the time, these defaults are just fine for running a production
# cluster. If you're fine-tuning your cluster, or wondering about the
# effect of certain configuration option, please _do ask_ on the
# mailing list or IRC channel [http://elasticsearch.org/community].

# Any element in the configuration can be replaced with environment variables
# by placing them in ${...} notation. For example:
#
#node.rack: ${RACK_ENV_VAR}

# For information on supported formats and syntax for the config file, see
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/setup-configuration.html>


################################### Cluster ###################################

# Cluster name identifies your cluster for auto-discovery. If you're running  
# multiple clusters on the same network, make sure you're using unique names.
# cluster.name可以確定你的集群名稱，當你的elasticsearch集群在同一個網段中會自動的找到具有相同cluseter.name的elasticsearch服務.
#  所以同一個網段具有多個elasticsearch集群時,確保cluster.name成為同一個集群的標示.
#cluster.name: elasticsearch





#################################### Node #####################################

# Node names are generated dynamically on startup, so you're relieved
# from configuring them manually. You can tie this node to a specific name:
# 節點名稱,可自動生成也可手動配置.
#node.name: "Franz Kafka"

# Every node can be configured to allow or deny being eligible as the master,
# and to allow or deny to store the data.
# 
# Allow this node to be eligible as a master node (enabled by default):
# 允許該節點成為master(默認開啟)
#node.master: true
#
# Allow this node to store data (enabled by default):
#允許該節點存儲數據(默認開啟)
#node.data: true

# You can exploit these settings to design advanced cluster topologies.
# 你可以通過這些選項配置高性能集群拓撲結構的模式.
# 1. You want this node to never become a master node, only to hold data.
#    This will be the "workhorse" of your cluster.
# 1. 如果你想讓節點從不選舉為主機節點，只用來存儲數據，可作為負載器
#node.master: false
#node.data: true
#
# 2. You want this node to only serve as a master: to not store any data and
#    to have free resources. This will be the "coordinator" of your cluster.
# 2. 如果你想讓節點成為主節點，且不存儲任何數據，并保留空閑資源，可作為協調器
#node.master: true
#node.data: false
#
# 3. You want this node to be neither master nor data node, but
#    to act as a "search load balancer" (fetching data from nodes,
#    aggregating results, etc.)
# 3. 如果你想讓節點既不成為主節點，又不成為數據節點，那么可將它作為搜索器，從節點獲取數據，生成搜索結果.
#node.master: false
#node.data: false

# Use the Cluster Health API [http://localhost:9200/_cluster/health], the
# Node Info API [http://localhost:9200/_nodes] or GUI tools
# such as <http://www.elasticsearch.org/overview/marvel/>,
# <http://github.com/karmi/elasticsearch-paramedic>,
# <http://github.com/lukas-vlcek/bigdesk> and
# <http://mobz.github.com/elasticsearch-head> to inspect the cluster state.

# A node can have generic attributes associated with it, which can later be used
# for customized shard allocation filtering, or allocation awareness. An attribute
# is a simple key value pair, similar to node.key: value, here is an example:
#
#node.rack: rack314

# By default, multiple nodes are allowed to start from the same installation location
# to disable it, set the following:
#node.max_local_storage_nodes: 1


#################################### Index ####################################

# You can set a number of options (such as shard/replica options, mapping
# or analyzer definitions, translog settings, ...) for indices globally,
# in this file.
#
# Note, that it makes more sense to configure index settings specifically for
# a certain index, either when creating it or by using the index templates API.
#
# See <http://elasticsearch.org/guide/en/elasticsearch/reference/current/index-modules.html> and
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/indices-create-index.html>
# for more information.

# Set the number of shards (splits) of an index (5 by default):
# 設置索引的分片數，默認為5
#index.number_of_shards: 5

# Set the number of replicas (additional copies) of an index (1 by default):
# 設置索引的副本數,默認為1
#index.number_of_replicas: 1

# Note, that for development on a local machine, with small indices, it usually
# makes sense to "disable" the distributed features:
#
#index.number_of_shards: 1
#index.number_of_replicas: 0

# These settings directly affect the performance of index and search operations
# in your cluster. Assuming you have enough machines to hold shards and
# replicas, the rule of thumb is:
#
# 1. Having more *shards* enhances the _indexing_ performance and allows to
#    _distribute_ a big index across machines.
# 2. Having more *replicas* enhances the _search_ performance and improves the
#    cluster _availability_.
#  1.如果服務器夠多，可以將分片提高，盡量將數據平均分布到大集群中去
   2.增加副本數量可以提高搜索性能.
# The "number_of_shards" is a one-time setting for an index.
#   分片數索引一次性生成的，后去不可更改設置
# The "number_of_replicas" can be increased or decreased anytime,
# by using the Index Update Settings API.
#    副本數可以通過API去實時增加或減少.
# Elasticsearch takes care about load balancing, relocating, gathering the
# results from nodes, etc. Experiment with different settings to fine-tune
# your setup.

# Use the Index Status API (<http://localhost:9200/A/_status>) to inspect
# the index status.


#################################### Paths ####################################

# Path to directory containing configuration (this file and logging.yml):
# 配置文件存儲位置
#path.conf: /path/to/conf

# Path to directory where to store index data allocated for this node.
# 數據存儲位置
#path.data: /path/to/data
#
# Can optionally include more than one location, causing data to be striped across
# the locations (a la RAID 0) on a file level, favouring locations with most free
# space on creation. For example:
# 多個數據存儲位置，有利于性能提升
#path.data: /path/to/data1,/path/to/data2

# Path to temporary files:
# 臨時文件的路徑
#path.work: /path/to/work

# Path to log files:
# 日志文件的路徑
#path.logs: /path/to/logs

# Path to where plugins are installed:
# 插件安裝路徑
#path.plugins: /path/to/plugins


#################################### Plugin ###################################

# If a plugin listed here is not installed for current node, the node will not start.
# 設置插件作為啟動條件，如果以下插件沒有安裝，則該節點服務不會啟動
#plugin.mandatory: mapper-attachments,lang-groovy


################################### Memory ####################################

# Elasticsearch performs poorly when JVM starts swapping: you should ensure that
# it _never_ swaps.
# 當JVM開始寫入交換空間(swapping) Elasticsearch 性能會低下，應該保持它不會寫入交換空間.
# Set this property to true to lock the memory:
# 設置這個屬性為true來鎖定內存
#bootstrap.mlockall: true

# Make sure that the ES_MIN_MEM and ES_MAX_MEM environment variables are set
# to the same value, and that the machine has enough memory to allocate
# for Elasticsearch, leaving enough memory for the operating system itself.
# 確保ES_MIN_MEM 和ES_MAX_MEM 環境變量設置為相同的值,以及機器有足夠的內存分配給ES.

# You should also make sure that the Elasticsearch process is allowed to lock
# the memory, eg. by using `ulimit -l unlimited`.
  #需要允許elasticsearch的進程可以鎖住內存，linux 可以使用ulimit -l unlimited

############################## Network And HTTP ###############################

# Elasticsearch, by default, binds itself to the 0.0.0.0 address, and listens
# on port [9200-9300] for HTTP traffic and on port [9300-9400] for node-to-node
# communication. (the range means that if the port is busy, it will automatically
# try the next port).

# Set the bind address specifically (IPv4 or IPv6):
# 設置綁定的ip地址,可以是ipv4或ipv6的,默認為0.0.0.0
#network.bind_host: 192.168.0.1

# Set the address other nodes will use to communicate with this node. If not
# set, it is automatically derived. It must point to an actual IP address.
# 設置其他節點和該節點交互的ip地址,如果不設置，值必須是個真實的ip地址
#network.publish_host: 192.168.0.1

# Set both 'bind_host' and 'publish_host':
# 同時設置bind_host和publish_host上面2個參數
#network.host: 192.168.0.1

# Set a custom port for the node to node communication (9300 by default):
# 設置節點間交互的tcp端口,默認是9300
#transport.tcp.port: 9300

# Enable compression for all communication between nodes (disabled by default):
# 設置是否壓縮tcp傳輸時的數據,默認為false，不壓縮
#transport.tcp.compress: true

# Set a custom port to listen for HTTP traffic:
# 設置對外服務的http端口
#http.port: 9200

# Set a custom allowed content length:
# 設置請求內容的最大容量,默認為100mb
#http.max_content_length: 100mb

# Disable HTTP completely:
# 使用http協議對外提供服務,默認為true，開啟
#http.enabled: false


################################### Gateway ###################################

# The gateway allows for persisting the cluster state between full cluster
# restarts. Every change to the state (such as adding an index) will be stored
# in the gateway, and when the cluster starts up for the first time,
# it will read its state from the gateway.
  #下面配置控制怎樣以及何時啟動一整個集群重啟的初始化恢復過程.(當使用shard gateway時,是為了盡可能的重用local data(本地數據))
# There are several types of gateway implementations. For more information, see
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/modules-gateway.html>.

# The default gateway type is the "local" gateway (recommended):
# gateway類型,默認為local即為本地文件系統，可以設置為本地文件系統
#gateway.type: local

# Settings below control how and when to start the initial recovery process on
# a full cluster restart (to reuse as much local data as possible when using shared
# gateway).

# Allow recovery process after N nodes in a cluster are up:
# 在一個集群中的N個節點啟動后，才允許恢復處理
#gateway.recover_after_nodes: 1

# Set the timeout to initiate the recovery process, once the N nodes
# from previous setting are up (accepts time value):
# 設置初始化恢復過程的超時時間,超時時間從上一個配置中配置的N個節點啟動后算起
#gateway.recover_after_time: 5m

# Set how many nodes are expected in this cluster. Once these N nodes
# are up (and recover_after_nodes is met), begin recovery process immediately
# (without waiting for recover_after_time to expire):
# 設置這個集群中期望有多少個節點,一旦這N個節點啟動(并且recover_after_nodes也符合)，立即開始恢復過程(不等待revover_after_time超時)
#gateway.expected_nodes: 2


############################# Recovery Throttling #############################

# These settings allow to control the process of shards allocation between
# nodes during initial recovery, replica allocation, rebalancing,
# or when adding and removing nodes.
  #下面這些配置允許在初始化恢復，副本分配，再平衡或添加和刪除節點時控制節點間的分片分配設置。
# Set the number of concurrent recoveries happening on a node:
#
# 1. During the initial recovery
# 1. 初始化數據恢復時，并發恢復線程的個數，默認為4
#cluster.routing.allocation.node_initial_primaries_recoveries: 4
#
# 2. During adding/removing nodes, rebalancing, etc
# 2. 添加刪除節點或負載均衡時并發恢復線程的個數，默認為2
#cluster.routing.allocation.node_concurrent_recoveries: 2

# Set to throttle throughput when recovering (eg. 100mb, by default 20mb):
# 設置恢復時的吞吐量
#indices.recovery.max_bytes_per_sec: 20mb

# Set to limit the number of open concurrent streams when
# recovering a shard from a peer:
# 設置來限制從其他分片恢復數據時最大同時打開并發流的個數，默認為5
#indices.recovery.concurrent_streams: 5


################################## Discovery ##################################

# Discovery infrastructure ensures nodes can be found within a cluster
# and master node is elected. Multicast discovery is the default.

# Set to ensure a node sees N other master eligible nodes to be considered
# operational within the cluster. This should be set to a quorum/majority of 
# the master-eligible nodes in the cluster.
# 設置這個參數來保證集群中的節點可以知道其他N個有master資格的節點，默認為1，對應大的集群來說，可以設置大一點的值(2-4)
#discovery.zen.minimum_master_nodes: 1

# Set the time to wait for ping responses from other nodes when discovering.
# Set this option to a higher value on a slow or congested network
# to minimize discovery failures:
# 檢測超時時間，默認3秒，設置這個選項應對網絡擁擠的時候，防止腦裂，降低故障。
#discovery.zen.ping.timeout: 3s

# For more information, see
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/modules-discovery-zen.html>

# Unicast discovery allows to explicitly control which nodes will be used
# to discover the cluster. It can be used when multicast is not present,
# or to restrict the cluster communication-wise.
#
# 1. Disable multicast discovery (enabled by default):
# 設置是否打開多播發現節點，默認是true
# 當多播不可用或者集群跨網段的時候集群通信還是用單播了。
#discovery.zen.ping.multicast.enabled: false
#
# 2. Configure an initial list of master nodes in the cluster
#    to perform discovery when new nodes (master or data) are started:
# 這是一個集群中的主節點的初始列表，當節點(主節點或者數據節點)啟動時使用這個列表進行探測
#discovery.zen.ping.unicast.hosts: ["host1", "host2:port"]

# EC2 discovery allows to use AWS EC2 API in order to perform discovery.
#
# You have to install the cloud-aws plugin for enabling the EC2 discovery.
#
# For more information, see
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/modules-discovery-ec2.html>
#
# See <http://elasticsearch.org/tutorials/elasticsearch-on-ec2/>
# for a step-by-step tutorial.

# GCE discovery allows to use Google Compute Engine API in order to perform discovery.
#
# You have to install the cloud-gce plugin for enabling the GCE discovery.
#
# For more information, see <https://github.com/elasticsearch/elasticsearch-cloud-gce>.

# Azure discovery allows to use Azure API in order to perform discovery.
#
# You have to install the cloud-azure plugin for enabling the Azure discovery.
#
# For more information, see <https://github.com/elasticsearch/elasticsearch-cloud-azure>.

################################## Slow Log ##################################

# Shard level query and fetch threshold logging.

#index.search.slowlog.threshold.query.warn: 10s
#index.search.slowlog.threshold.query.info: 5s
#index.search.slowlog.threshold.query.debug: 2s
#index.search.slowlog.threshold.query.trace: 0ms

index.search.slowlog.threshold.fetch.warn: 1s
index.search.slowlog.threshold.fetch.info: 800ms
index.search.slowlog.threshold.fetch.debug: 500ms
index.search.slowlog.threshold.fetch.trace: 0ms

#index.indexing.slowlog.threshold.index.warn: 10s
#index.indexing.slowlog.threshold.index.info: 5s
#index.indexing.slowlog.threshold.index.debug: 2s
#index.indexing.slowlog.threshold.index.trace: 500ms

################################## GC Logging ################################

#monitor.jvm.gc.young.warn: 1000ms
#monitor.jvm.gc.young.info: 700ms
#monitor.jvm.gc.young.debug: 400ms

#monitor.jvm.gc.old.warn: 10s
#monitor.jvm.gc.old.info: 5s
#monitor.jvm.gc.old.debug: 2s

################################## Security ################################

# Uncomment if you want to enable JSONP as a valid return transport on the
# http server. With this enabled, it may pose a security risk, so disabling
# it unless you need it is recommended (it is disabled by default).
#
#http.jsonp.enable: true

來自： http://my.oschina.net/davehe/blog/591364