# ======================== Elasticsearch Configuration =========================
#
# NOTE: Elasticsearch comes with reasonable defaults for most settings.
# Before you set out to tweak and tune the configuration, make sure you
# understand what are you trying to accomplish and the consequences.
#
# The primary way of configuring a node is via this file. This template lists
# the most important settings you may want to configure for a production cluster.
#
# Please consult the documentation for further information on configuration options:
# https://www.elastic.co/guide/en/elasticsearch/reference/index.html
#
# ---------------------------------- Cluster -----------------------------------
#
# Use a descriptive name for your cluster:
#
#cluster.name: my-application
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
#node.name: node-1
#
# Add custom attributes to the node:
#
#node.attr.rack: r1
#
# ----------------------------------- Paths ------------------------------------
#
# Path to directory where to store the data (separate multiple locations by comma):
#
#path.data: /path/to/data
#
# Path to log files:
#
#path.logs: /path/to/logs
#
# ----------------------------------- 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 -----------------------------------
#
# By default Elasticsearch is only accessible on localhost. Set a different
# address here to expose this node on the network:
#
#network.host: 192.168.0.1
#
# By default Elasticsearch listens for HTTP traffic on the first free port it
# finds starting at 9200. Set a specific HTTP port here:
#
#http.port: 9200
#
# For more information, consult the network module documentation.
#
# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when this node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
#
#discovery.seed_hosts: ["host1", "host2"]
#
# Bootstrap the cluster using an initial set of master-eligible nodes:
#
#cluster.initial_master_nodes: ["node-1", "node-2"]
#
# For more information, consult the discovery and cluster formation module documentation.
#
discovery.seed_hosts: ["127.0.0.1:9300"]
cluster.initial_master_nodes: ["localhost"]
# ---------------------------------- Various -----------------------------------
#
# Allow wildcard deletion of indices:
#
#action.destructive_requires_name: false
#----------------------- BEGIN SECURITY AUTO CONFIGURATION -----------------------
#
# The following settings, TLS certificates, and keys have been automatically
# generated to configure Elasticsearch security features on 30-12-2024 12:29:02
#
# --------------------------------------------------------------------------------
# Enable security features
xpack.security.enabled: false
xpack.security.enrollment.enabled: true
# Allow HTTP API connections from anywhere
# Connections are encrypted and require user authentication
http.host: 0.0.0.0
# Allow other nodes to join the cluster from anywhere
# Connections are encrypted and mutually authenticated
transport.host: 0.0.0.0
#----------------------- END SECURITY AUTO CONFIGURATION -------------------------
复制代码
==============================安装遇到的具体问题分析==================
运行后
Elasticsearch security features have been automatically configured!
✅ Authentication is enabled and cluster connections are encrypted.
ℹ️ Password for the elastic user (reset with `bin/elasticsearch-reset-password -u elastic`):
7b9UkBY*NeEH3_ea85JG
ℹ️ HTTP CA certificate SHA-256 fingerprint:
d7a127636d720f927127c4f974f806f512eae01dd8b85af21be192dd5bbb3c3c
ℹ️ Configure Kibana to use this cluster:
• Run Kibana and click the configuration link in the terminal when Kibana starts.
• Copy the following enrollment token and paste it into Kibana in your browser (valid for the next 30 minutes):
eyJ2ZXIiOiI4LjE0LjAiLCJhZHIiOlsiMTkyLjE2OC4xNTAuNTA6OTIwMCJdLCJmZ3IiOiJkN2ExMjc2MzZkNzIwZjkyNzEyN2M0Zjk3NGY4MDZmNTEyZWFlMDFkZDhiODVhZjIxYmUxOTJkZDViYmIzYzNjIiwia2V5IjoiYVR5VkY1UUJWLTBzb19zV0UzT246UkhSangyMFRReWl1ZzZPeUtWSVJIQSJ9
ℹ️ Configure other nodes to join this cluster:
• On this node:
⁃ Create an enrollment token with `bin/elasticsearch-create-enrollment-token -s node`.
⁃ Uncomment the transport.host setting at the end of config/elasticsearch.yml.
⁃ Restart Elasticsearch.
• On other nodes:
⁃ Start Elasticsearch with `bin/elasticsearch --enrollment-token <token>`, using the enrollment token that you generated.
重要信息：
elastic user 的密码是 7b9UkBY*NeEH3_ea85JG
重置密码的命令 bin/elasticsearch-reset-password -u elastic
使用：bin/elasticsearch-create-enrollment-token -s node创建一个token, 但这个还用不上
"取消对config/exelasticsearch.yml末尾transport.host设置的注释。重新启动Elasticsearch。
8、修改elasticsearch.yml
cd /usr/local/software/elasticsearch/config
备份下
cp elasticsearch.yml elasticsearch_bak.yml
修改
vi elasticsearch.yml
把它的注释去掉，然后保存重启。
transport.host: 0.0.0.0
[2024-12-30T21:00:35,801][ERROR][o.e.b.Elasticsearch ] [localhost.localdomain] node validation exception
[2] bootstrap checks failed. You must address the points described in the following [2] lines before starting Elasticsearch. For more information see [https://www.elastic.co/guide/en/elasticsearch/reference/8.17/bootstrap-checks.html]
bootstrap check failure [1] of [2]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]; for more information see [https://www.elastic.co/guide/en/elasticsearch/reference/8.17/bootstrap-checks-file-descriptor.html]
bootstrap check failure [2] of [2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]; for more information see [https://www.elastic.co/guide/en/elasticsearch/reference/8.17/bootstrap-checks-max-map-count.html]
ERROR:
这个错误信息说明 Elasticsearch 在启动时执行了 bootstrap checks（启动检查），并且未通过两个关键的检查。具体来说，出现了以下两个问题：
错误信息解析：
max file descriptors 设置过低
错误信息：[bootstrap check failure [1] of [2]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]]
解释：Elasticsearch 需要较高的文件描述符限制，因为它会同时打开很多文件（例如索引文件、日志文件等）。默认情况下，操作系统可能只允许最多 4096 个文件描述符，而 Elasticsearch 要求至少 65535 个。
vm.max_map_count 设置过低
错误信息：[bootstrap check failure [2] of [2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]]
解释：vm.max_map_count 是操作系统设置的最大虚拟内存区域数（用于内存映射文件）。Elasticsearch 需要更高的这个值，特别是在处理大数据量时。默认值可能较低（如 65530），而 Elasticsearch 要求至少 262144。
如何解决这些问题：
1. 增加 max file descriptors 限制
你需要增加操作系统中可打开文件的最大数量。方法如下：
查看当前设置：
bash
ulimit -n
如果显示的数字小于 65535，你需要增加它。
临时修改（只对当前会话有效）：
bash
ulimit -n 65535
永久修改（适用于 Linux）：
编辑 /etc/security/limits.conf 文件，添加以下行：
星号（*）代表对所有用户应用该限制
* soft nofile 65535
* hard nofile 65535
如果你知道运行 Elasticsearch 的用户（例如 elasticsearch 用户），你可以替换星号为该用户名：
elasticsearch soft nofile 65535
elasticsearch hard nofile 65535
还需要修改 /etc/pam.d/common-session 或 /etc/pam.d/login 文件（具体路径取决于发行版），并添加以下行：
centos7 用这个/etc/pam.d/login
加在最后
session required pam_limits.so
最后，重新启动机器或注销当前会话后生效。
2. 增加 vm.max_map_count 限制
vm.max_map_count 控制了每个进程可以映射的最大虚拟内存区域数量。需要将其增加到至少 262144：
临时修改：
bash
sudo sysctl -w vm.max_map_count=262144
永久修改：
编辑 /etc/sysctl.conf 文件：
bash
sudo vi /etc/sysctl.conf
添加或修改以下行：
bash
vm.max_map_count=262144
运行以下命令以使配置立即生效：
bash
sudo sysctl -p
3. 重启 Elasticsearch
完成上述设置后，重启 Elasticsearch：
bash
sudo systemctl restart elasticsearch
或者如果你是手动启动 Elasticsearch，则执行：
bash
./bin/elasticsearch
总结：
max file descriptors 的问题：增加文件描述符的限制到 65535。
vm.max_map_count 的问题：增加虚拟内存映射区域的限制到 262144。
完成配置后重启 Elasticsearch，应该能够顺利启动。
如果还有其他问题，或者配置后仍然无法启动，可以查看 Elasticsearch 的日志（/usr/local/software/elasticsearch/logs/elasticsearch.log）来获取更多详细的错误信息。
启动说没权限，继续修改目录权限
如果 Elasticsearch 进程没有足够的权限来写入该目录，你可以更改该目录的权限，使得 Elasticsearch 有权访问它。假设 Elasticsearch 是以 elasticsearch 用户运行的，你可以执行以下命令来修复权限。
给目录赋予适当的权限：
bash
sudo chown -R elasticsearch:elasticsearch /usr/local/software/elasticsearch/logs/
这条命令将目录的所有权授予 elasticsearch 用户和组。
确保目录具有正确的读写权限：
bash
sudo chmod -R 755 /usr/local/software/elasticsearch/logs/
这样，目录将具有所有者的读、写和执行权限，其他用户只有读和执行权限。
3. 检查日志文件权限
同样需要确保日志文件本身（elasticsearch.log）的权限设置正确。执行以下命令来检查日志文件的权限：
查看日志文件的权限：
ls -l /usr/local/software/elasticsearch/logs/elasticsearch.log
删除elasticsearch.keystore
[root@localhost config]# rm elasticsearch.keystore
rm: remove regular file ‘elasticsearch.keystore’? y
从你提供的日志信息来看，Elasticsearch 在启动时遇到了 bootstrap 检查失败，并且因为 缺少配置 导致启动失败。错误消息中指出了如下问题：
错误描述
bootstrap check failure [1] of [1]: the default discovery settings are unsuitable for production use; at least one of [discovery.seed_hosts, discovery.seed_providers, cluster.initial_master_nodes] must be configured;
这意味着 Elasticsearch 发现你没有配置必要的发现设置，这是在生产环境中启动集群时的强制要求。具体来说，Elasticsearch 需要知道如何找到集群的节点和确定主节点。
解决办法
编辑 Elasticsearch 配置文件
Elasticsearch 的配置文件 elasticsearch.yml 存在于你的 Elasticsearch 安装目录下的 config 目录中，例如：/usr/local/software/elasticsearch/config/elasticsearch.yml。
添加 Discovery 配置
在该文件中，你需要添加以下配置来启用节点发现机制。对于单节点部署，可以配置 discovery.seed_hosts 或 cluster.initial_master_nodes。
如果你的环境是 单节点（即只有一个 Elasticsearch 实例），你可以添加以下配置：
yaml
# discovery.seed_hosts 用于指定初始节点列表，Elasticsearch 用它来查找其他节点
discovery.seed_hosts: ["127.0.0.1:9300"]
# 或者你可以使用 cluster.initial_master_nodes 指定初始的主节点列表
cluster.initial_master_nodes: ["localhost"]
如果你部署的是 多节点集群，你需要配置集群中的所有节点的 IP 地址。例如：
yaml
discovery.seed_hosts: ["node1_ip:9300", "node2_ip:9300", "node3_ip:9300"]
cluster.initial_master_nodes: ["node1", "node2", "node3"]
discovery.seed_hosts 用于帮助节点相互发现，而 cluster.initial_master_nodes 用于在集群启动时指定初始的主节点。
重启 Elasticsearch
修改配置文件后，重启 Elasticsearch 服务。你可以使用以下命令来启动 Elasticsearch：
vi /usr/local/software/elasticsearch/config/elasticsearch.yml
discovery.seed_hosts: ["127.0.0.1:9300"]
cluster.initial_master_nodes: ["localhost"]
bash
./bin/elasticsearch